New findings of specialists at Boston University

According to a trial, treatment with dutasteride (Avodart), a 5-alpha reductase inhibitor, doesn’t influence negatively on muscle mass in healthy men who use testosterone.
A research related to this issue was conducted. While fat-free mass was increased by 0,6-7,1 kg during 20 weeks in men that used dutasteride and Testosterone Enanthate, fat-free mass was increased by 0,8-8,1 kg in those who administered placebo and testosterone. As for muscle power, sexual functions and volume of prostate, they didn’t differ in males of these two groups.
5-alpha reductase inhibitors are used clinically for treatment of benign prostatic hyperplasia (BPH) and androgenic alopecia. These are disorders which commonly affect middle-aged and elderly men.
DHT represents the main metabolite of testosterone. But the role of DHT in human development is not studied well. It is suggested that DHT has relevant role in development of prostate and phallus.
Middle-aged and old men with low testosterone levels who apply testosterone medicines have risks connected with decreased muscle mass and sexual problems.
Specialists also put efforts to develop nonsteroidal selective androgen receptor modulators (SARMs). It is affirmed that SARMs and 5-alpha reductase inhibitors are safe because DHT is supposedly not necessary for effects on fat-free mass, strength and sexual activity. It is also doubted whether DHT plays any role for androgen’s effects on hematocrit, hemoglobin, lipids and several other factors.
Shalender Bhasin and his colleagues at the Boston University have conducted a clinical trial in order to see whether 5?-reduction to DHT is required in order to mediate androgen’s effects on muscle mass. Moreover, the experts evaluated role of 5?-reduction on sexual functions, hematocrit and levels of lipid.
The research conducted by Bhasin and his colleagues implicated healthy men that were 18- 50 years old and had normal levels of testosterone. They used Testosterone Enanthate and dutasteride or placebo. Quantities of Testosterone Enanthate varied from 50 to 600 mg weekly.
Since 5 ?-reductase inhibitors increase testosterone levels, all males were given also gonadotropin-releasing hormone agonist in order to block natural testosterone.
The results of the study manifested that fat-free mass was enhanced due to usage of testosterone. It didn’t differ significantly in males of these two groups. Muscle power which was also increased due to application of testosterone didn’t differ between the two groups as well. Sexual activity, prostate volume, sebum production, hemoglobin, acne, hematocrit didn’t differ essentially between those who were given placebo and dutasteride.
The experts affirm that effectiveness of 5?-reductase inhibitors may be limited in males that have normal or high testosterone levels. That’s why it is necessary to check testosterone levels in order to determine how bodies will respond to 5 ?-reductase inhibitors.
So, the study has manifested that muscle mass is not affected by 5?-reductase inhibitors.  Males should know that if they have high testosterone levels or introduce exogenous testosterone in their bodies, 5?-reductase inhibitors will not lead to shrunken prostate.