MedlinePlus Herbs and Supplements: Zinc

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Zinc

Contents of this page:
Background Synonyms Evidence Dosing	Safety Interactions Methodology Selected references

Zinc

BackgroundReturn to top

Zinc has been used since ancient Egyptian times to enhance wound healing, although the usefulness of this approach is only partially confirmed by the clinical data of today.

Zinc is necessary for the functioning of more than 300 different enzymes and plays a vital role in an enormous number of biological processes. Zinc is a cofactor for the antioxidant enzyme superoxide dismutase (SOD) and is in a number of enzymatic reactions involved in carbohydrate and protein metabolism.

Its immune-enhancing activities include regulation of T lymphocytes, CD4, natural killer cells, and interleukin II. In addition, zinc has been claimed to possess antiviral activity. It has been shown to play a role in wound healing, especially following burns or surgical incisions. Zinc is necessary for the maturation of sperm and normal fetal development. It is involved in sensory perception (taste, smell, and vision) and controls the release of stored vitamin A from the liver. Within the endocrine system, zinc has been shown to regulate insulin activity and promote the conversion thyroid hormones thyroxine to triiodothyronine.

Based on available scientific evidence, zinc may be effective in the treatment of (childhood) malnutrition, acne vulgaris, peptic ulcers, leg ulcers, infertility, Wilson's disease, herpes, and taste or smell disorders. Zinc has also gained popularity for its use in the prevention of the common cold.

The role for zinc is controversial in some cases, as the results of published studies provide either contradictory information and/or the methodological quality of the studies does not allow for a confident conclusion regarding the role of zinc in those diseases.

SynonymsReturn to top

Atomic number 30, Indian tin, pewter, polaprezinc, zinc acetate, zinc acexamate, zinc aspartate, zinc carbonate, zinc citrate, zinc chloride, zinc gluconate, zinc methionate, zinc methionine, zinc monomethioine, zinc oxide, zinc picolinate, zinc sulfate, Zink, ZN, Zn.

Brands used in clinical trials: A-84, Articulin-F®, Astra, Curiosin® (zinc and hyaluronic acid), Herpigon, Nels Cream®, Orazinc®, Solvezink®, Virudermin Gel®, Zeta N, Zicam® Nasal Gel, Zincolak, Zincomed, Zineryt®, Zinvit-C250.

EvidenceReturn to top

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidence	Grade^*
Diarrhea (children) Multiple studies in developing countries found that zinc supplementation in malnourished children with acute diarrhea may reduce the severity and duration of diarrhea, especially in children with low zinc levels.	A
Gastric ulcers The healing process of gastric ulcers may be enhanced through treatment with zinc, although further studies will be needed to determine to what extent zinc may be beneficial for patients with this condition. Most studies report no or few adverse effects associated with its use.	A
Sickle cell anemia (management) There is strong scientific evidence to suggest that zinc may help manage or reduce symptoms of sickle cell anemia. Most of these studies reported increased height, weight, immune system function, and testosterone levels and decreased numbers of crises and sickled cells following zinc treatment.	A
Zinc deficiency Causes: Zinc deficiency is caused by inadequate intake or absorption, increased zinc excretion, or increased bodily need for zinc. Symptoms: Zinc deficiency symptoms include growth retardation, hair loss, diarrhea, delayed sexual maturation, impotence, eye and skin conditions, and loss of appetite. Additional symptoms may include weight loss, delayed wound healing, taste changes, and mental lethargy.Diagnosis: Zinc can be measured in plasma, red blood cells, white blood cells, and hair.	A
Acne vulgaris Based on high-quality studies, topical or oral use of zinc seems to be a safe and effective treatment for acne vulgaris; however, some studies report no or negative effects of zinc. Additionally, many studies used combination treatments. Several studies have identified a positive correlation between serum zinc levels and severity of acne, while others did not, and it remains to be determined to what degree internal zinc levels may correlate with the severity of acne.	B
Attention deficit hyperactivity disorder (ADHD) Early studies have shown a correlation between low serum free fatty acids and zinc serum levels in children with attention deficit hyperactivity disorder. Additional studies found that zinc supplements reduced hyperactive, impulsive, and impaired socialization symptoms, but did not reduce attention deficiency symptoms. Zinc supplementation may be a more effective treatment for older children with higher body mass index (BMI) scores.	B
Down's syndrome In several studies, zinc supplements seemed to counteract hypothyroidism and slightly reduce the number of infections in children with Down syndrome. However, zinc did not seem to improve depressed immune systems. Additional human research is needed before a firm conclusion can be made.	B
Fungal infections (scalp) Evidence from human trials suggests that zinc pyrithione shampoo may be an effective treatment for tinea versicolor fungal infections of the scalp. No side effects were noted. Additional research is needed before a strong recommendation can be made.	B
Herpes simplex virus Low-quality studies have been conducted to assess the effects of zinc (topical or taken by mouth) on herpes type I or II. Several of these studies used combination treatments or permitted the continued use of other medications, so the exact role of zinc in those studies is unclear. However, the positive results obtained in most trials suggest that zinc may represent a safe and effective alternative treatment for herpes type I and II and should encourage further research into the topic using well-designed studies.	B
High cholesterol Zinc may improve blood cholesterol levels in hemodialysis patients. There is some evidence that zinc may improve cholesterol ratio of HDL "good cholesterol" versus LDL "bad cholesterol," which would be considered a positive effect. Well-designed clinical trials are needed before a strong recommendation can be made.	B
Immune function Zinc appears to be an essential trace element for the immune system, but research on the effect of zinc supplementation on immune function is scant and mostly focuses on patients with specific diseases. Zinc gluconate appears to have beneficial effects on immune cells. There are relatively few studies that examine zinc levels and the effects of zinc supplementation on the health of the elderly population. Further research is needed before a recommendation can be made.	B
Plaque/ gingivitis A few studies have reported significant reduction in plaque accumulation following treatment with zinc rinses and dentifrices. Preliminary research suggests that zinc citrate dentifrice may reduce the severity and occurrence of supragingival calculus formation. However, more well-designed studies are needed to confirm such benefits. More research might help to determine zinc's potential efficacy in other dental applications.	B
Wilson's disease Wilson's disease is an inherited disorder of copper metabolism characterized by a failure of the liver to excrete copper, which leads to its accumulation in the liver, brain, cornea, and kidney, with resulting chronic degenerative changes. Early research suggests that zinc treatment may be effective in the management of Wilson's disease. Relatively few cases of adverse effects have been reported, including one case report presenting a fatality; however, it is unclear whether or not the death was caused by zinc. Several studies have been conducted by the same authors, resulting in possible bias. More well-designed trials are needed to confirm these early results.	B
Alopecia (hair loss) A few studies that examined the efficacy of zinc in treating alopecia report conflicting results. Additional information is needed before a conclusion can be made.	C
Anorexia nervosa Reports of zinc's effectiveness in treating symptoms of anorexia nervosa observed in young adults are based on small, low-quality studies, but all agree on the beneficial effects of zinc. Well-designed trials with a larger number of participants are needed to confirm these results.	C
Bad breath Chewing gum containing zinc or rinsing out the mouth with a solution containing zinc seemed to reduce bad breath (halitosis) in early studies.	C
Beta-thalassemia (hereditary disorder) One small study noted that children with beta-thalassemia who took oral zinc supplements for 1-7 years increased in height more than those who did not take zinc. More studies are needed to confirm these findings.	C
Blood disorders (aceruloplasminemia) Data from case reports suggest a potential role for zinc supplementation in aceruloplasminemia, a neurodegenerative disease caused by a gene mutation.	C
Boils In one study, patients with recurrent boils (furunculosis) treated with zinc found their furuncles did not reappear. Well-designed clinical trials are needed to confirm this potential benefit.	C
Burns Study results of zinc sulfate supplements given to burn victims to increase healing rate yield mixed results. Further research is needed before a recommendation can be made.	C
Chronic prostatitis (CP) Early studies suggest that zinc supplements taken with antibiotics may be more effective than antibiotics alone in reducing pain, urinary symptoms, quality of life, and maximum urethra closure pressure for patients with chronic prostatitis. Further research is needed to confirm these results.	C
Closed head injuries Early poorly designed studies indicate that zinc supplementation may enhance neurological recovery in patients with closed head injuries. Further research is needed to confirm these results.	C
Cognitive deficits (children) Early studies indicate that daily supplementation with zinc may be of limited usefulness for improving cognition in lead-exposed schoolchildren. Further study may be warranted in this area.	C
Common cold There are conflicting results regarding the effect of zinc formulations in treating duration and severity of common cold symptoms. Although zinc might be beneficial in the treatment of cold symptoms, more studies are needed to clarify which zinc formulations may be most effective, which rhinoviruses are affected by zinc, and if nasal sprays provide a useful alternative application route for zinc treatment. A recent study found no significant differences between zinc nasal spray and placebo.Negative results may be caused by using doses of zinc that are too low or they may be affected by the presence of compounds like citric or tartaric acid, which may reduce efficacy due to chelating of the zinc ion.	C
Crohn's disease Early studies of zinc supplements in patients with Crohn's disease have found positive results. Well-designed clinical trials are needed to confirm these results.	C
Dandruff Shampoo containing 1% of zinc pyrithione has been shown to reduce dandruff in some people.	C
Diabetes (type 1 and type 2) Diabetic patients typically have significantly lower serum zinc levels compared with healthy controls. In early high-quality studies, zinc supplementation for type-2 diabetics may have beneficial effects in elevating serum zinc level and in improving glycemic control that is shown by decreasing HbA1c concentration. Further study is needed before a strong recommendation can be made.	C
Diabetic neuropathy (nerve damage) Oral zinc supplementation may improve glycemic control and severity of peripheral neuropathy. Further research is needed before a recommendation can be made.	C
Diaper rash Zinc may reduce the incidence of diaper rash and have a preventative effect.	C
Eczema There are conflicting data regarding the correlation of zinc serum levels and eczema. One study noted that zinc might have caused an increase in itching after several weeks of supplementation. Additional information is needed to help clarify these results.	C
Exercise performance Zinc may improve exercise performance in athletes with low serum zinc or zinc deficiencies. Additional evidence is needed before a recommendation can be made.	C
Gilbert's syndrome Gilbert's syndrome is a common, often inherited disorder that affects processing by the liver of the greenish-brown pigments in bile (called bilirubin). The resulting abnormal increase of bilirubin in the bloodstream can lead to yellowing of the skin (jaundice), but the liver itself remains normal. It is more common in men than women and is named after a French gastroenterologist. Zinc sulfate supplementation seemed to decrease serum unconjugated bilirubin levels in a small study. Well-designed clinical trials are needed to confirm these results.	C
Growth (stunted infants) Evidence suggests that supplementation with zinc plus iron (but not with zinc alone) may improve linear growth (length) of stunted infants with low hemoglobin.	C
Hepatic encephalopathy Hepatic encephalopathy is abnormal brain function caused by passage of toxic substances from the liver to the blood. Early high-quality trials of zinc for this indication have yielded conflicting results.	C
Hepatitis C viral infection (chronic) Early studies have shown that zinc in combination with interferon or interferon and ribavirin for hepatitis C viral infection patients did not show significant benefits, except for lower incidence of gastrointestinal side effects in one study. Further study may be warranted in this area. Recent high-quality evidence suggests that supplementation with polaprezinc in patients undergoing treatment with pegylated interferon alpha-2b and ribavirin may decrease damage to the liver cells.	C
HIV/AIDS Patients with HIV/AIDS, especially those with low zinc levels, may benefit from zinc supplementation. Some low-quality studies cite reduction in infections, enhanced weight gain, and immune system function, including increased CD4 and CD8 cells. However, other low quality studies conflict with these findings. Further research is needed before a conclusion can be drawn.	C
Hypothyroidism Case report data suggest zinc supplementation may improve thyroid hormone levels (particularly T3) among women with hypothyroidism.	C
Incision wounds Although zinc is frequently thought to have beneficial effects on incision wound healing, few studies have investigated this use. Further research is needed before a firm recommendation can be made.	C
Infertility Many studies report beneficial results of zinc supplements on infertility, as expressed in improved sperm quality and number, although this effect may depend on the cause of infertility. A minor increase in abnormal spermatozoa in subfertile males taking zinc was noted in one study. Additional information is needed before a firm conclusion can be drawn.	C
Kidney function Early studies show potential improvement in uremic patients taking zinc supplements. Further research is needed to confirm these results. Zinc supplementation may be recommended only in the patients with proven zinc deficiency, but for all chronic renal failure patients it is questionable.	C
Kwashiorkor (malnutrition from inadequate protein intake) Short-term zinc supplementation may increase weight gain and decrease infections, swelling, diarrhea, anorexia, and skin ulcers in children with extreme malnourishment.	C
Leg ulcers There are conflicting findings regarding the potential benefit of zinc for healing leg ulcers. All studies, however, reported no or few adverse effects.	C
Leprosy A few studies have examined the efficacy of zinc treatment in leprosy. Studies of zinc taken by mouth report positive results, while one study of topical zinc reports negative results. Further research is needed before a conclusion can be drawn.	C
Liver cirrhosis People with alcoholic liver cirrhosis may be deficient in zinc. Preliminary studies suggest that zinc may benefit these patients. Further evidence is needed to confirm these findings.	C
Lower respiratory infections in children Results from large clinical trials suggest that supplementation with zinc may reduce the incidence and severity of lower respiratory infections. Some studies suggest these effects to be only apparent in boys and not girls. A trend toward increased respiratory infections in children has been noted in one study. A recent study does not support the use of zinc supplementation in the management of acute lower respiratory infections requiring hospitalization in indigenous children living in remote areas. Due to conflicting results, further research is needed before a conclusion can be drawn. Future studies could examine whether these adult populations have a similar response.	C
Macular degeneration Most studies examining the relationship between dietary zinc intake over many years and macular degeneration have not reported positive correlations. However, one large high-quality study, which examined the efficacy of zinc supplements in preventing loss of visual acuity, found that zinc supplements helped prevent the occurrence of age-related macular degeneration. Since study results are conflicting, additional well-designed clinical trials are needed before a recommendation can be made.	C
Malaria Results are contradictory for the effect of zinc on malaria symptoms. Some high-quality studies suggest no effect of zinc supplementation on the severity of malaria. Other studies suggest that zinc supplementation may reduce the number of stays in hospital and death rate due to P . falciparum infection. Further well-designed trials are required to address these discrepancies.	C
Menstrual cramps Case report data suggest a possible role for zinc supplementation in menstrual cramps. Additional study is needed to confirm these findings.	C
Muscle cramps (cirrhosis) The results of one case series suggest that zinc supplementation may improve muscle cramps in patients with cirrhosis. Further research is needed to confirm these results.	C
Mortality Evidence from high-quality studies found no association between zinc supplementation and mortality among children. Additional study is needed in this area.	C
Parasites In a few studies of varying quality, patients with cutaneous leishmaniasis were injected with zinc sulfate intralesionally. One study found zinc sulfate was better than meglumine antimoniate for the first four weeks, but no statistical differences were observed after six weeks. Zinc may decrease the severity of infection and re-infection of S . mansoni , but does not seem to prevent initial infection. More research should be done in this area to examine how zinc affects the S . mansoni life cycle and whether this data can be extrapolated to other species of Schistosoma . The effects of zinc on the rate of parasitic re-infestation have been examined in children. No significant effect of zinc treatment was found. Recent high-quality study data suggest that supplementation with zinc and vitamin A may favorably alter infection rate and duration among children. Due to conflicting results in this area, more research is needed before zinc can be recommended for the treatment of parasites.	C
Poisoning (arsenic) Results from one study show that a combination of spirulina extract plus zinc may be useful for the treatment of chronic arsenic poisoning with melanosis and keratosis. More research is needed to confirm the effects of zinc alone.	C
Pregnancy According to multiple reviews, there is no evidence to suggest that zinc supplementation offers benefits during pregnancy, although there is a possible reduction in labor complications and pre-term deliveries. However, results from individual studies suggest a possible benefit of zinc supplementation on blood pressure during pregnancy. Further research is needed before a conclusion can be drawn.	C
Psoriasis There are only a few studies that examine the efficacy of zinc treatment on symptoms of psoriasis, including psoriasis induced arthritis-like symptoms. One trial noted a reduction in pain and joint swelling. Other studies do not support a role for zinc in alleviating the symptoms of psoriasis. Further, well-designed clinical trials are required to clarify these results.	C
Radiation-induced mucositis Radiation has the potential side effect of mucositis, which is inflammation of mucous membranes inside of the mouth, nose, and throat. Two trials suggest that zinc may lower the degree of mucositis in patients on radiation. Further research is needed to confirm these results.	C
Respiratory disease (respiratory papillomatosis) Evidence from case reports suggests a possible role for zinc supplementation as adjuvant therapy in JORRP. This area warrants further investigation.	C
Rheumatoid arthritis Most trials do not show significant improvements in arthritis symptoms following zinc treatment. Interpretation of some data is difficult because patients in the studies were permitted to continue their previous arthritis medication and most studies used a small number of participants. Well-designed clinical trials are needed before a decision can be made.	C
Skin damage caused by incontinence Early evidence suggests that topical zinc oxide oil may help manage perianal and buttock skin damage in incontinent patients. Further research is needed to confirm these results.	C
Stomatitis Zinc sulfate has been studied for the treatment of recurrent aphthous stomatitis (RAS, mouth ulcer). Study results conflict and no clear conclusion can be drawn at this time.	C
Taste perception (hemodialysis, cancer) Results from studies investigating the potential role of zinc in treating taste and smell disorders are contradictory. Recently, a large high-quality trial showed no evidence of a benefit of zinc supplementation on taste alterations among patients undergoing radiation therapy for head and neck cancer. Well-designed research is needed to determine if zinc contributes to the treatment of taste and smell disorders.	C
Tinnitus Studies on the efficacy of zinc in treating tinnitus yield contradictory results based on subjective findings. Further research is necessary before a conclusion can be drawn.	C
Trichomoniasis Little research is available on the efficacy of zinc for the treatment of trichomoniasis, a sexually transmitted disease (STD). One very small study suggests that a zinc sulfate douche and the prescription antibiotic metronidazole may effectively treat patients with recalcitrant trichomoniasis. However, more well-designed human studies are necessary before a firm conclusion can be drawn.	C
Viral warts Studies have found conflicting results of the effect of zinc on viral warts. Well-conducted studies are needed to clarify these early results.	C
Celiac disease In a very small study, oral zinc supplements did not seem to improve the clinical condition of patients with unresponsive celiac syndrome.	D
Chronic inflammatory rheumatic disease Early studies found that zinc supplementation did not seem to benefit patients with chronic inflammatory rheumatic disease.	D
Continuous ambulatory peritoneal dialysis (CAPD) Zinc supplementation did not improve the nutritional status in patients on CAPD based on one well-designed trial.	D
Cystic fibrosis Zinc supplementation does not seem to affect clinical status, growth velocity, or lung function in children with cystic fibrosis.	D
Inflammatory bowel disease Early studies have found that zinc supplementation does not seem to improve inflammatory bowel disease.	D
Pneumonia (children) Studies have found that zinc supplementation does not seem to lessen the duration of abnormally fast breathing, hypoxia (inadequate oxygen), chest indrawing, inability to feed, lethargy, severe illness, or hospitalization in children.	D

*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.

Grading rationale

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Acrodermatitis enteropathica, alcoholism, Alzheimer's disease, benign prostate hyperplasia, bladder cancer, bulimia, cancer, diabetic retinopathy, diarrhea (AIDS), encephalopathy, eye disorders (night blindness, retinol pigmentation abnormalities), hypoxia, human papilloma virus, hypogonadism, hyperprolactinemia, liver enlargement and disorders, menopause, nutritional deficiencies (consumption of dirt), pancreatitis, psychosis, Parkinson's disease, poisoning (nickel), schizophrenia, seizures, skin disorders (parakeratosis), smell disorders, spleen disorders (enlargement), tuberculosis, wound healing.

DosingReturn to top

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

Oral:

Acetazolamide side effects: 0.2 grams zinc sulfate three times daily has been studied in those with grave acetazolamide-induced side effects.

Acne vulgaris: Doses ranging from 45-220 milligrams of zinc sulfate (Orazinc® or effervescent), three times daily, up to 12 weeks have been studied. Doses of 45-135 milligrams of zinc in divided doses have been studied for up to 12 weeks, and 30-200 milligrams zinc gluconate has been used for three months.

Acrodermatitis enteropathica: Various doses have been studied: 100 milligrams zinc, three times daily; 45 milligrams, two times daily; 30-65 milligramsdaily; 200 milligrams per day (Solvezink®, Tika AB); 135 milligrams zinc sulfate daily; 220 milligrams, three time daily, or 50 milligrams, twice daily; 45 milligrams zinc, three times daily (Solvezink®, Tika AB); and 45 milligrams zinc, three times daily for two months.

Acute lymphoblastic leukemia: 0.02 milligrams/kilogram body weight of zinc has been studied as an adjunct therapy for leukemia.

Alopecia areata: Zincomed, 220 milligrams zinc sulfate twice daily has been studied for three months.

Anorexia: 45-100 milligrams daily of zinc, zinc sulfate, or zinc acetate have been studied. 15 milligrams zinc (as sulfate), three times daily for two weeks, followed by 50 milligrams, three times daily, has also been used.

Burns: A dose of 660 milligrams of zinc sulfate (ZnSO4) has been used.

Cancer: 90 milligrams zinc sulfate per day for five days, with a maintenance dose of 180 milligrams per day, has been used to treat pustules in a woman with squamous cell carcinoma and a zinc deficiency.

Chronic inflammatory rheumatic disease: 45 milligrams zinc as gluconate has been used daily for two months.

Cirrhosis/alcoholism: 200 milligrams as sulfate has been used three times daily. A daily oral intake of 200 milligrams of zinc sulfate for two months has been studied for its immune-enhancing effects in these patients.

Common cold/lower respiratory infection: Doses ranged from 4.5-23.7 milligrams zinc/lozenge and were taken every half hour during waking hours. Lozenges containing 5 milligrams or 11.5 milligrams zinc acetate or 13.3 milligrams zinc gluconate (Quigley Corporation PA) were taken every 2-3 waking hours (total of six lozenges per day). Zinc lozenges (Heiko Chemicals, PA) containing zinc acetate, 42.96 milligrams, 12.8 milligrams zinc) have been studied. Zinc lozenges with 10 milligrams zinc (Quigley Corporation) has been used three times daily. 23 milligrams zinc (as gluconate) lozenges has been taken daily for seven days. Lozenges (Quigley Corporation, PA) containing zinc (13.3 milligrams zinc gluconate trihydrate with molar concentrations of glycine) have been used every two hours of waking time. Effervescent lozenges (containing 10 milligrams zinc acetate) taken for three days, and at least four lozenges a day, have also been studied. 23 milligrams zinc lozenges containing 2% citric acid were taken every half hour while awake. 23 milligrams zinc lozenges (Truett Laboratories, TX) were used in one study where patients were instructed to let them dissolve in their mouth. Initial dose consisted of two lozenges, then one every two hours.

Continuous ambulatory peritoneal dialysis (CAPD): 100 milligrams per day of elemental zinc for three months has been studied.

Crohn's disease: 60 milligrams per day ZnSO4; 200 milligrams per day ZnSO4 for three months has been studied for thyroid function in Crohn's disease patients. 200 milligrams of zinc sulfate daily for six weeks has also been studied.

Cutaneous leishamaniasis: 2.5-10 milligrams of zinc sulfate has been used (Analar [BDH]).

Dental application: One or two pieces of a zinc chewing gum for at least 10 minutes, three times daily for one week has been studied to treat halitosis. 0.5% zinc citrate dentifrice has also been studied for three months.

Diabetes: 30 milligrams per day as amino acid chelate for three weeks. 30 milligrams of zinc, (as glycine) for three weeks has been given to alleviate oxidate stress in diabetics; 30 milligrams of zinc (as gluconate) has been studied; 50 milligrams zinc has been used daily for 28 days.

Diabetic neuropathy: Zinc sulfate (660mg) for six weeks has been studied.

Dialysis: 50 milligrams per day as acetate have been used in dialysis patients for effects on lymphocyte and granulocyte function.

Diaper rash: 10 milligrams zinc gluconate supplements have been used as an adjunct to anti-fungal cream for diaper rash.

Down syndrome/hypothyroidism: Zinc supplements (1mg/kg/body weight) for two months, followed by a 10-month break, and then again for two months of zinc treatment. 135 milligrams zinc (as sulfate) daily for two months.

Dysgeusia: Zinc gluconate 140 milligrams daily has been used.

Eczema: 220 milligrams of daily oral zinc treatment as sulfate has been studied.

Exercise performance: Zinc at 3 milligrams/kilogram body weight has been studied for four weeks.

Furunculosis: 45 milligrams have been used three times daily (Solvezink®, Tika) for four weeks.

Gastro-duodenal ulcers: Doses of zinc acexamate 300-1,800 milligrams, three times daily have been studied for five weeks with maintenance doses of 600 milligrams for up to six months. 220 milligrams zinc sulfate taken three times daily for three weeks has also been used

Gastro-intestinal disease: 300 milligrams zinc acexamate has been taken per day.

Gastric/gastroduodenal ulcers: A-84, 300 milligrams, three times daily for three weeks. Doses of zinc acexamate 300-600 milligrams per day. 220 milligrams as sulfate, three times per day for four weeks.

Gilbert's syndrome: 40 milligrams of ZnSO4 in a single dose has been used for acute conditions, and 100 milligrams ZnSO4 in a single dose has been given for seven days for chronic conditions.

Hepatic encephalopathy: Zinc sulfate or zinc acetate, 600 milligrams, has been used for seven to ten days.

Hypercholesterolemia: 7.7 micromoles zinc sulfate (50 milligrams elemental zinc) for 90 days has been studied.

Hyperlipidemia: 150 milligrams zinc daily for 12 weeks has been studied.

Hyperprolactinemia: 37.5 micrograms oral zinc as sulfate and 15.9 milligrams as sulfate has been used three times daily for 60 days.

HIV/AIDS: 200 milligrams of zinc sulfate has been used daily for four weeks as an aid in immune response. Zinc gluconate (125 milligrams of zinc gluconate has been used twice daily for three weeks.

Immune function: 30 milligrams zinc daily for 14 weeks has been investigated. 200 milligrams of zinc sulfate has been used for two months.

Immune function in the elderly: 25 milligrams of zinc phosphate has been investigated. 220 milligrams zinc sulfate, twice daily for one month. 50, 100, and 150 milligrams elemental zinc has been used daily. 12 milligrams of Zn+ has been used daily for one month in infected elderly subjects.

Infertility: 50 milligrams zinc per day. 66 milligrams zinc sulfate per day for 26 weeks has been used to improve sperm count in fertile and subfertile males. 250 milligrams of zinc sulfate has been used twice daily for three months. 220 milligrams of zinc sulfate has been used once daily, for four months (Cap, ZINCOLAK, Shalaks Chemicals). 440 milligrams zinc sulfate for 12 months. 220 milligrams zinc sulfate for impotence and hypogonadism in hepatic cirrhosis patients. 500 milligrams zinc has been used daily as a supplement with hydrochlorothiazide and sexual side effects.

Inflammatory bowel disease: 300 milligrams zinc aspartate (equal to 60 milligrams elemental zinc) has been used daily for four weeks.

Intestinal malabsorption: 100 milligrams, three times daily and 19 milligrams daily have been used.

Leg ulcers: 220 milligrams zinc sulfate, 1-3 times daily for up to 10 months has been studied. 200 milligrams zinc sulfate, three times daily (Solvezink®, Astra), for up to one year.

Leprosy: 220 milligrams zinc sulfate daily has been studied as an adjunct to leprosy medication for up to 18 months.

Macular degeneration: 100 milligrams, two times per day for up to two years.

Muscle cramps (cirrhosis): 220 milligrams twice-daily oral zinc sulfate thrice weekly for 12 weeks has been used.

Nickel-positive patients: Zinc sulfate 100 milligrams, three times per day, for 30 days has been studied.

Pancreatitis/home parenteral nutrition: 30 milligrams zinc sulfate for the first three days of total parenteral nutrition has been used.

Pregnancy: 30 milligrams elemental zinc has been studied during the last two trimesters of pregnancy, but did not improve birth outcome in Bangladeshi urban poor. 14 milligrams iron and 250 micrograms folate with 15 milligrams zinc has been studied in pregnancy.

Psoriasis: 220 milligrams, three times daily for the first for six weeks, then six months. 220 milligrams zinc sulfate three times daily for two months. 50 milligrams of zinc, three times daily.

Rheumatoid arthritis: 220 milligrams of zinc sulfate three times daily has been used up to (Mericon Industries, Ill) 12 weeks. 220 milligrams has been used three times daily for six months (356). 200 milligrams has been used three times daily. 220 milligrams zinc sulfate, three times daily for at least two months (Solvezink®, Astra). 600 milligrams has been used every 24 hours, (divided up into three doses) for eight months, but showed little success.

Sickle cell anemia: 220 milligrams zinc, three times per day has been used. 75 milligrams of zinc supplements have been used daily for up to three years. A solution of 1% of zinc sulfate in distilled water has been used. 15 milligrams zinc as acetate has been used twice daily. 25 milligrams every four hours has been studied to enhance healing of leg ulcers and control sickling of erythrocytes in people with sickle cell anemia. 15 milligrams zinc as acetate, has been used three times daily for 12 months to treat serum testosterone deficiency in adults with sickle cell anemia.

Skin lesions: 400 milligrams zinc sulfate has been used daily.

Stomatitis: A dose of 200 milligrams zinc sulfate once daily for up to 12 weeks has been studied.

Supplementation: 15 milligrams or 100 milligrams daily for three months has been studied in healthy, elderly people.

Supragingingival calculus formation: Dentrifices containing 0.5% zinc citrate have been used.

Taste disorders: 45 milligrams zinc sulfate, three times daily has been used as an adjunct to external radiotherapy. 100 milligrams zinc ion has been used daily for three months. 220 milligrams of zinc sulfate has been used daily for six weeks. 29 milligrams of zinc picolinate capsules have been used three times daily for three months. 100 milligrams zinc sulfate has been used daily for six months. 50 milligrams of zinc acetate has been used daily.

Tinnitus: 22 milligrams of zinklet tablets (slow release tablets) have been taken three times daily for over eight weeks. 50 milligrams of zinc has been taken daily. Zinc (34-68 milligrams per day, for two weeks).

Trichomoniasis: 220 milligrams Zincaps has been used twice daily for three weeks to treat trichomoniasis infection that was unresponsive to metronidazole.

Viral warts: Oral zinc sulfate has been given at doses ranging from 10 to 600 milligrams per kilogram-1 daily for up to six months.

Wilson's disease: Various maintenance doses have been studied. For example, 25-150 milligrams zinc acetate in divided doses has been taken for up to one year. Doses of 25-50 milligrams three times daily have been investigated for maintaining copper balance in those with Wilson's disease. For zinc sulfate, doses used have ranged from 100 to 400 milligrams, three times per day.

Wound healing: 220 milligrams zinc sulfate, three times per day has been used following surgery to promote wound healing.

Topical:

Acne vulgaris: Erythromycin (4%) plus 1.2% zinc for 12 weeks is a commonly studied dose. This dose has been studied for up one year in clinical studies.

Dandruff: Shampoo containing 1% zinc pythione (ZPT) has been shown to reduce the number of PAS-positive microorganisms (but not Gram-positive micro-organisms).

Dental application: 0.5% zinc citrate has been used.

Herpes: Two applications daily of 0.3% zinc oxide/glycine cream has been studied. Virunderim Gel®, containing 10 milligrams zinc sulfate has also been used up to 12 days. 0.01%-0.05% zinc sulfate solutions has been applied often during a breakout and once a week during remission. Immersion treatment with liquid soap containing 1% zinc sulfate has been used for three months followed by weekly application. A 4% zinc sulfate solution in water has also been used.

Immune enhancement: 10 milligrams zinc gluconate has been studied, and during diarrhea, 20 milligrams of zinc gluconate has been reported.

Leg ulcers: Topical 250-510 micrograms/centimeter2 topical zinc oxide in polyvinyl pyrrolidone has been studied for eight weeks. Zinc oxide dressings (Mezinc®) have been investigated for eight weeks. Gauze compress medicated with zinc oxide (400 micrograms ZnO/cm2) has been studied for eight weeks.

Psoriasis: Cow udder ointment (containing zinc) has been studied for psoriasis.

Sebum levels: Erythromycin lotions (4%) with (1.2%, Zineryt® lotion) have been studied for three months for effects on sebum levels.

Sickle cell anemia: 10 milligrams daily of zinc in a 5 milliliter cherry soup has been taken for one year.

Trichomoniasis: Zinc sulfate douche (1%) and metronidazole has been used.

Intravenous, Intramuscular:

Anorexia: 40 micromoles of zinc per day, intravenously for seven days, followed by 15 milligrams per day for 60 days has been reported.

Cutaneous leishmaniasis: Intralesional injections of ZS 2% and ZnSO4 2% have been studied.

Nasal:

Common cold: 0.12% zinc sulfate nasal spray administered four times per day into each nostril has been reported. Gels containing zinc gluconate (Zicam®) have been used at the recommended dose of one spray (120 microliters) into each nostril, every four hours.

Children (under 18 years old)

Childhood malnutrition: 10 milligrams per day or 1milligram/kilogram body weight per day by mouth has been studied.

Common cold: 10 milligrams per day taken by mouth or 23 milligrams zinc lozenges (Truett Laboratories, TX) have been studied with initial dose consisting of one lozenge (half of the adult dose) every two hours, not to exceed six per day.

Diarrhea: Children aged six months to two years received zinc (20 milligrams as acetate, in syrup) for treatment of dehydration and diarrhea; 14.2 milligrams zinc acetate or 40 milligrams zinc acetate has also been studied in six month-old to two year-old children, respectively. In 3-24 month-old infants, 20 milligrams zinc acetate per day for two weeks has been used. Zinc syrup containing 15 milligrams zinc was used on 6-11 month-old children and 30 milligrams with 12-35 month-old children. 15 milligrams (in children younger than or equal to 12 months old) or 30 milligrams (in children older than 12 months old) elemental zinc daily in three divided doses has been studied for 14 days. Another study reported using 10 milligrams zinc per day for five days of the week or 50 milligrams zinc once weekly for 16 weeks. Other doses used in children include 20 milligrams zinc daily for up to two weeks; 20 milligrams of zinc as sulfate, two times per day; 10-20 milligrams zinc in a multivitamin formula for six months; multivitamin juice with 15 milligrams zinc acetate/kilogram body weight; 10 milligrams zinc sulfate in 4 milliliters liquid per day, for seven months; and zinc gluconate (elemental zinc 10 milligrams) to infants and 20 milligrams to older children.

Down syndrome: 20 milligrams/kilogram zinc per day for two months showed an increase in DNA synthesis. 50 milligrams (for up to six months) and 1 milligram/kilogram per day (for up to four months) zinc have shown a reduction in the number of infections.

Eczema: 22.5 milligrams zinc, three times per day (in sustained release capsules), for eight weeks has been reported.

HIV/AIDS: 1.8-2.2 milligrams/kilogram body weight per day, for three to four weeks, has been studied as an immune response aid in children.

Infection: 20 milligrams zinc for one year has been studied for stunted growth and episodes of infectious disease.

Infection with Schistosoma mansoni : 30-50 milligrams, as zinc sulfate five times a week for 12 months, has been studied for S . mansoni infection in children .

Kwashiorkor: Doses of 2-5 milligrams/kilogram zinc supplements have been studied for one week in children.

Lower respiratory tract infections: Studied doses include 10 milligrams zinc gluconate six times a week; 10 milligrams zinc sulfate in 4 milliliters liquid per day, for seven months; 10 milligrams to infants and 20 milligrams to older children or placebo for four months; and 10 milligrams zinc as acetate (twice daily for five days).

Malaria: Studied doses include 12.5 milligrams zinc sulfate for six days per week for six months; 10 milligrams zinc gluconate per day, six days per week; 10 milligrams elemental zinc for six days a week for 46 weeks; and zinc 20 milligrams day for infants or 40 milligrams per day for older children for four days.

Parasites: Zinc supplements 10 milligrams as amino acid chelate have been used.

Sickle cell anemia: Zinc 10 milligrams per day in 5 milliliters cherry soup has been used in children.

Taste perception: Zinc chelate 1 milligram/kilogram daily for three months has been used in children.

Wilson's disease: Pediatric patients of 1-5 years of age were given 25 milligrams of zinc twice daily; patients of 6-15 years of age, if under 125 pounds body weight, were given 25 milligrams of zinc three times daily; and patients 16 years of age or older were given 50 milligrams of zinc three times daily.

SafetyReturn to top

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Case study evidence reports a patient with zinc oxide allergy.

Side Effects and Warnings

Zinc is regarded as a relatively safe and generally well tolerated when taken at recommended doses, and few studies report side effects. Occasionally, adverse effects such as nausea, vomiting, or diarrhea have been observed.

Sideroblastic anemia, leukopenia, microcytic anemia, and neutropenia have been reported in individual case reports following the ingestion of large amounts of zinc.

Reduced levels of high-density-lipoprotein (HDL) "good" cholesterol have been observed following daily supplementation with zinc.

Unpleasant taste, taste distortion, and abdominal cramping have been occasionally reported, especially in studies examining the efficacy of zinc containing lozenges in treating symptoms of common cold or treatment of diarrhea in children. Bleeding gastric erosion, hepatitis (liver inflammation), liver failure, and intestinal bleeding have been reported in individual case reports following the ingestion of higher zinc doses.

Acute tubular necrosis and interstitial nephritis have been reported following the ingestion of large amounts of zinc (doses not specified). Patients with severe kidney disease should reduce or omit taking zinc because it is primarily eliminated in urine.

There is one case report of a fatal outcome from cystic degeneration in putamen and necrosis in the hypothalamus. It was reported as a consequence of zinc treatment for Wilson's disease; however, the patient had received penicillamine, followed by a relatively high dose of zinc per day for several weeks, followed by penicillamine again for an unspecified time so it remains unclear if zinc was responsible for the death.

Slight tingling or burning sensation in the nostril has been reported from zinc nasal gel. A trend toward increased respiratory infections in children has been noted. One case of hypersensitivity pneumonitis has been reported.

Reports of skin conditions have been noted. In one study, worsening of an acne condition was observed following topical application of zinc, although many studies show positive effects of zinc on acne. A case report suggested the presence of dermatitis due to zinc deficiency.

High-quality studies have found evidence of an association between high-dose zinc supplement use and hospitalization for urinary complications, including benign prostatic hyperplasia/urinary retention, urinary tract infection, and urinary lithiasis. This was especially evident among males.

There is one report of death following the ingestion of 400 coins (mostly pennies). Pennies are composed mostly of zinc. Reduced immune responses have also been observed in a small study.

Pregnancy and Breastfeeding

Pregnancy, Category A: Zinc is categorized as Pregnancy Category A. If this drug is used during pregnancy, the possibility of fetal harm appears remote. Because studies cannot rule out the possibility of harm, however, zinc acetate should only be used during pregnancy if clearly needed. Zinc appears to be safe in amounts that do not exceed the established tolerable upper intake level.

Pregnancy, Category C: Animal reproduction studies have not been conducted with zinc chloride. It is also not known whether zinc chloride can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Zinc chloride should be given to a pregnant woman only if clearly needed under medical supervision.

InteractionsReturn to top

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

Hormone replacement therapy and cholestyramine may reduce zinc excretion in the urine. Amiloride (Midamor®) reduces urinary zinc excretion and increases zinc blood levels. Theoretically, concurrent use of amiloride with zinc supplementation could cause zinc toxicity. Chlorthalidone (Hygroton®) may increase serum zinc levels.

Caffeine and alcohol may decrease zinc concentrations. Birth control pills, loop and thiaide diurectics may decrease zinc absorption.

Deferoxamine (Desferal®) increases urinary zinc elimination. Captopril (Capoten®) and enalapril (Vasotec®) might increase urinary zinc excretion in patients with high blood pressure. Data on other ACE-inhibitor (ACEIs) drugs is lacking. The clinical consequence of urinary zinc loss in patients with high blood pressure is unknown.

Zinc sulfate may interact with carbenoxolone analog (BX24).

Supplementation with zinc has the potential to improve the efficacy of oral cholera vaccine in children.

Zinc may interact with LDL, HDL lipoproteins, and triglycerides, reducing HDL "good" cholesterol levels. Use cautiously with cholesterol medications, due to possible additive effects.

Zinc may increase the cytotoxicity of cisplatin (Platinol-AQ®) when in the presence of the chelate ethylenediaminetetraacetic acid (EDTA), as compared to cisplatin treatment alone.

Zinc may decrease the absorption of erythromycin. However, in a study comparing erythromycin with and without added zinc, the results showed a significant reduction in severity and number of acne vulgaris lesions (including inflamed lesions) in the zinc treated group compared to those taking erythromycin alone.

Zinc may decrease the effectiveness of fluoroquinolone antibiotics (e.g. Cipro®). Zinc decreases the absorption and serum levels of demeclocycline, minocycline, and tetracycline due to zinc binding. Doxycycline does not seem interact with zinc. Penicillamine (Cuprimine®) chelates zinc and can reduce the effects of supplemental zinc. Dosing time should be separated by at least two hours.

Zinc may improve both insulin secretion and insulin sensitivity and may exert insulin-like effects. Use cautiously with diabetes medications.

High amounts of zinc may result in the prevention of interferon release, and interact with Interferon Alfa-2B (Intron A®).

Pancreatic enzyme replacements may improve absorption of zinc compared to pancreatic insufficiency.

Zinc supplementation has been shown to alter thyroid hormone metabolism in disabled patients with zinc deficiency.

Interactions with Herbs and Dietary Supplements

Zinc may interact with LDL, HDL lipoproteins, and triglycerides, reducing HDL "good" cholesterol levels. Use cautiously with herbs and supplements taken for cholesterol, due to possible additive effects.

Zinc may interfere with copper metabolism. However, one study indicates no detrimental effects of zinc on plasma copper levels in healthy volunteers over a period of six weeks.

Non-heme iron may decrease zinc absorption. Non-heme iron and zinc compete for a common absorption pathway in the gut. However, when iron and zinc are taken with food, this interaction is not likely to occur. When taken with food, zinc absorption is facilitated by proteins in food through an alternate pathway that does not compete with iron. Protein-bound heme iron (found in red meats) does not seem to affect zinc absorption.

Zinc supplementation has been shown to alter thyroid hormone metabolism in disabled patients with zinc deficiency.

Zinc may intereact with herbs and supplements that contain caffeine or have blood pressure-altering, antibiotic, hormonal, diabetic, hypoglycemic, or diuretic effects.

Methodology Return to top

This information is based on a systematic review of scientific literature, and was peer-reviewed and edited by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com): Dawn Costa, BA, BS (Natural Standard Research Collaboration); Jenna Hollenstein, MS, RD (Natural Standard Research Collaboration); Shaina Tanguay-Colucci, BS (Natural Standard Research Collaboration); Catherine Ulbricht, PharmD (Massachusetts General Hospital); Christine Ulbricht, BS (University of Massachusetts); Wendy Weissner, BA (Natural Standard Research Collaboration).

Methodology details

Selected references Return to top

Aggarwal R, Sentz J, Miller MA. Role of zinc administration in prevention of childhood diarrhea and respiratory illnesses: a meta-analysis. Pediatrics 2007 Jun;119(6):1120-30.
Al-Maroof RA, Al-Sharbatti SS. Serum zinc levels in diabetic patients and effect of zinc supplementation on glycemic control of type 2 diabetics. Saudi Med J 2006 Mar;27(3):344-50.
Dvornik S, Cuk M, Racki S, Zaputovic L. Serum zinc concentrations in the maintenance hemodialysis patients. Coll Antropol 2006 Mar;30(1):125-9.
Eby GA, Halcomb WW. Ineffectiveness of zinc gluconate nasal spray and zinc orotate lozenges in common-cold treatment: a double-blind, placebo-controlled clinical trial. Altern Ther Health Med 2006 Jan-Feb;12(1):34-8.
Halyard MY, Jatoi A, Sloan JA, et al. Does zinc sulfate prevent therapy-induced taste alterations in head and neck cancer patients? Results of phase III double-blind, placebo-controlled trial from the North Central Cancer Treatment Group (N01C4). Int J Radiat Oncol Biol Phys 2007 Apr 1;67(5):1318-22.
Hodkinson CF, Kelly M, Alexander HD, et al. Effect of zinc supplementation on the immune status of healthy older individuals aged 55-70 years: the ZENITH Study. J Gerontol A Biol Sci Med Sci 2007 Jun;62(6):598-608.
Lukacik M, Thomas RL, Aranda JV. A meta-analysis of the effects of oral zinc in the treatment of acute and persistent diarrhea. Pediatrics 2008 Feb;121(2):326-36.
Mahomed K, Bhutta Z, Middleton P. Zinc supplementation for improving pregnancy and infant outcome. Cochrane Database Syst Rev 2007 Apr 18;(2):CD000230.
Prasad AS, Beck FW, Bao B, et al. Zinc supplementation decreases incidence of infections in the elderly: effect of zinc on generation of cytokines and oxidative stress. Am J Clin Nutr 2007 Mar;85(3):837-44.
Richard SA, Zavaleta N, Caulfield LE, et al. Zinc and iron supplementation and malaria, diarrhea, and respiratory infections in children in the Peruvian Amazon. Am J Trop Med Hyg 2006 Jul;75(1):126-32.
Rico JA, Kordas K, Lopez P, et al. Efficacy of iron and/or zinc supplementation on cognitive performance of lead-exposed Mexican schoolchildren: a randomized, placebo-controlled trial. Pediatrics 2006 Mar;117(3):e518-27.
Sazawal S, Black RE, Ramsan M, et al. Effect of zinc supplementation on mortality in children aged 1-48 months: a community-based randomized placebo-controlled trial. Lancet 2007 Mar 17;369(9565):927-34.
Suzuki H, Sato K, Takagi H, et al. Randomized controlled trial of consensus interferon with or without zinc for chronic hepatitis C patients with genotype 2. World J Gastroenterol 2006 Feb 14;12(6):945-50.
Tielsch JM, Khatry SK, Stoltzfus RJ, et al. Effect of daily zinc supplementation on child mortality in southern Nepal: a community-based, cluster randomised, placebo-controlled trial. Lancet. 2007 Oct 6;370(9594):1230-9. Comment in: Lancet. 2007 Oct 6;370(9594):1194-5.
Walker CL, Bhutta ZA, Bhandari N, et al. Zinc during and in convalescence from diarrhea has no demonstrable effect on subsequent morbidity and anthropometric status among infants <6 mo of age. Am J Clin Nutr 2007 Mar;85(3):887-94.

March 01, 2008.

Natural Standard Logo This evidence-based monograph was prepared by the Natural Standard Research Collaboration. The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. Talk to your health care provider before taking any prescription or over the counter drugs (including any herbal medicines or supplements) or following any treatment or regimen. Copyright© 2009 Natural Standard (www.naturalstandard.com). All Rights Reserved.