Researchers first measured testosterone of single men in their early 20s who didn’t have children in 2005, then followed up 4 1/2 years later.

Results (1) The serum testosterone, penile growth, height, hand wrest strength, and hemoglobin were increased after androgen replacement (P<0.05).

Conclusion: 1 % of Carbomer 940, 67% of ethanol and isopropyl myristate were the optimum matrix of testosterone gel.