Hair Loss/Testosterone and hair
We know that testosterone also has a negative effect on human head hair follicles albeit less of an affect than DHT. Dutasteride raises scalp testosterone by 104% at .5 mg dosed every day. Blood serum testosterone levels also rise (likely because there is less testosterone being converted to DHT since 5 alpha reductase is being inhibited by dutasteride). Are dutasteride users potentially setting themselves up for a slower failure? What I mean by that is we are inhibiting DHT but slowly allowing testosterone to shrink away follices long term?
There are no long term studies for dutasteride, which would mimic a Type I and Type II 5 alpha reductase enzyme deficiency. What we do know is that a Type II enzyme deficiency does exist and the men in those families never go bald and never get prostate cancer. So, for a long term study already done by nature it would seem lowering DHT by 66% with finasteride right after puberty onwards or the Type II inherited deficiency both should show beneficial effects the longer you take them. I have not seen any long term thinning in my patients on dutasteride. If it exists after four decades of use someone will write a paper on it. Personally I do not think it will happen.