I've used 100mg/day of bio-identical natural testosterone for about three years now. And I've trained for 46 years. My doctor suggested putting me on it due to low test levels. I had a vascetomy 30 years ago. It's estimated that 35% of cases of premature viropause result from vasectomies, while about half the men going to impotence clinics have had them. They are not the "safe" surgeries we've been misled to believe in abstentia of longitudinal studies of those who've had them.
The only problem I've had with test occured a year ago. My PSAs shot up to 4.5. Doctored wanted to take me off it. In the case of that doctor (in a city I used to live in, no longer my physician with a thousand miles between us), he tended to defer to the compounding pharmacist - even seek info from him. With the PSAs, however, he deferred to AMA information. So I did my own research, then consulted with the compounding pharmacist. The vital information is all there in the writings of the late Dr John Lee, father figure of hrt for men and women using bio-identicals.
Compounding pharmacists tell you to apply the test to the inner forearms. Bad idea. The perinimu or balls would be worse. Any area rich in hair follicles is also rich in 5 alpha reductase, the enzyme that metabolizes test to DHT (full name is 5-alpha-dihydroxytestosterone). Areas lacking hair follicles and rich in capillaries are the best deal - such as the base of the neck and those cavities at the side of the neck/front of traps.
5-alpha metabolism can also be slowed down with saw pamento and zinc. Best of all, however, is available over the counter in health food stores in the menopause section: progesterone. half dose applied along with or before the test ensures cutting down metabolism completely.
I had blood work done two months later. Test was up to 850 ng/dl, PSAs down to 2.1. But I wasn't awarded an honorary doctorate for my research!
Does it work? I'm 61. At 200 lbs I rack out 8 reps on the bench with 265, reps with over 300 on the squat, upright row a pair of 80 lb dumbbells. I've learned the mental secrets of training, and am stronger than I've ever been.
Having seen men mature in strength and physique well into their late 70s throughout my life, I see no reason not to believe I'll keep on growing.
Hope this is of some benefit to the discourse here.