Inclusion Criteria:

• Males and females between the ages of 18-55. A female is eligible to enter and participate if she is of: non-childbearing potential (i.e., physiologically incapable of becoming pregnant); or, child-bearing potential, has a negative pregnancy test (urine or serum) at screen, and agrees to one of the following: Complete abstinence from intercourse from 2 weeks prior to administration of the investigational product, throughout the study, and for a time interval (5 days) after completion or premature discontinuation from the study; subjects utilizing this method must agree to use alternate method of contraception if they become sexually active and will be queried on whether they have been abstinent when they present to the clinic for the Final Visit or, Female sterilization; or, Sterilization of male partner; or, Implants of levonorgestrel; or, Injectable progestogen; or, Oral contraceptive (combined or progestogen only); or, Any intrauterine device (IUD) with published data showing highest expected failure rate is less than 1% per year (not all IUDs meet this criterion); or, Spermicide plus a mechanical barrier (e.g., spermicide plus a male condom or a female diaphragm). Any other barrier methods (only if used in combination with any of the above acceptable methods) or, Any other methods with published data showing highest expected failure rate for that method is less than 1% per year.
• Formally diagnosed ICHD 5.2.2 chronic post traumatic headache
• Have had traumatic brain injury (TBI) not more than 5 years prior to enrollment
• Medically stable as determined by Investigator
• On stabilized dosage of any headache preventive medications for 3 months prior to screening
• On stabilized dosage of concomitant medications at discretion of investigator
• Chronic headache history only after the TBI
• Able to understand and communicate intelligibly with study observer
• Able to take oral medication, adhere to the medication regimens and perform study procedures
• Able to read and comprehend written instructions and be willing to complete all procedures and assessments required by protocol
• Subject is able to demonstrate willingness to participate by signing and understanding an informed consent after full explanation of study
• Self-reported cognitive inefficiency or "brain-fog" during headache

Exclusion Criteria:

• History of hypersensitivity to triptan-like medication
• Pathology of salivary glands such as sialadenitis (e.g., Sjorgen's Syndrome, viral or bacterial sialadenitis, or obstructive sialadenitis)
• Any condition or symptom that would knowingly alter content of saliva
• History of, symptoms or signs of ischemic cardiac, cerebrovascular or peripheral vascular syndromes or other significant underlying cardiovascular disease. Ischemic cardiac syndromes include, but are not limited to, angina pectoris of any type (e.g. stable angina of effort and vasospastic forms of angina such as Prinzmetal variant, all forms of myocardial infarction, and silent myocardial ischemia. Cerebrovascular syndromes include, but are not limited to, strokes of any type as well as transient ischemic attacks. Peripheral vascular disease includes, but is not limited to, ischemic bowel disease.
• Any medication overuse that in the opinion of the investigator has exacerbated or contributed to current headache pattern of subject
• Uncontrolled hypertension, severe renal impairment, severe hepatic impairment, hemiplegic or basilar headache
• History of hypersensitivity to naratriptan or any components
• Pregnant, trying to get pregnant, or lactating
• Recent history of abuse of alcohol or other drugs that would interfere with participation
• Participation in another investigative drug study within previous 30 days
• Chronic pain syndromes, fibromyalgia, Gulf War Syndrome, and other multisystem diseases characterized by poor or no response to pain-reducing interventions
• Secondary gain is currently active complication to recovery (e.g., has a pending lawsuit for injuries from MVA in which concussion was sustained)