Rapid Changes in Serum Testosterone in Men with Newly Diagnosed Type 2 Diabetes With Intensive Insulin and Metformin

RCT (n=70) reports metformin lowered total (12.7 vs. 15.3 nmol/L), free (0.20 vs. 0.24 nmol/L), and bioavailable (4.56 vs. 5.31 nmol/L) testosterone vs. continued intensive insulin only (all P < 0.05); and effects of long-term metformin on testosterone in men need further study.

Source:

Diabetes Care