Inclusion Criteria:

1. Type 2 diabetes mellitus.
2. Serum testosterone 12 nmol/L or less on two consecutive samples taken on different days and symptoms compatible with hypogonadism.

3. Peripheral vascular disease as defined by

   • previous diagnosis by a specialist vascular surgeon OR
   • ABPI less than 0.92 and ischaemic leg pain (claudication or rest pain) or distal complications (non-healing arterial foot ulcer or gangrene).
4. Agreement to maintain antihypertensive and antilipid treatments at prior doses during 3 month duration of study.
5. Ability to give written informed consent after verbal and written explanation in the English language.
6. Ability to comply with all study requirements.

Exclusion Criteria:

1. Current or previous breast cancer.
2. Current or previous prostate cancer.
3. Raised prostate specific antigen (PSA) or abnormal per rectal examination unless prostate cancer excluded after specialist urology opinion.
4. Severe symptoms of benign prostatic hypertrophy (‘prostatism’)
5. Treatment with testosterone in the 3 months prior to the trial.
6. Investigational drug treatment in the 3 months prior to the trial.