New findings can change attitude to 5-alpha reductase inhibitors

According to a trial, treatment with dutasteride (Avodart), a 5-alpha reductase inhibitor, doesn’t influence negatively on muscle mass in healthy men who apply testosterone.
A study linked with this issue was performed. While fat-free mass was increased by 0,6-7,1 kg during 20 weeks in males that took dutasteride and Testosterone Enanthate, fat-free mass was increased by 0,8-8,1 kg in those who were given placebo and testosterone. As for muscle power, sexual functions and volume of prostate, they didn’t differ in men of these 2 groups.
5-alpha reductase inhibitors are utilized clinically to treat benign prostatic hyperplasia (BPH) and androgenic alopecia. These are disorders that usually affect middle-aged and elderly men.
DHT represents the chief metabolite of testosterone. But the role of DHT in human development is not is not understood. It is supposed that DHT has vital role in development of prostate and phallus.
Middle-aged and elder men with low testosterone levels who apply testosterone products have risks related to reduced muscle size 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 life. It is also doubted whether DHT has any role for androgen’s effects on hematocrit, hemoglobin, lipids and certain other factors.
Shalender Bhasin and his colleagues at the Boston University have conducted a clinical trial in order to define whether 5?-reduction to DHT is needed in order to mediate androgen’s effects on muscle mass. Moreover, the experts evaluated role of 5?-reduction on sexual activity, hematocrit and levels of lipid.
The study conducted by Bhasin and his colleagues involved healthy men who were 18- 50 years old and had normal levels of testosterone. They administered Testosterone Enanthate and dutasteride or placebo. Quantities of Testosterone Enanthate varied from 50 to 600 mg per week.
Since 5 ?-reductase inhibitors increase testosterone levels, all men 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 intake of testosterone. It didn’t differ significantly in men of these 2 groups. Muscle power that was also increased due to application of testosterone didn’t differ between the two groups as well. Sexual activity, volume of prostate, sebum production, hemoglobin, acne, hematocrit didn’t differ substantially between those who were given placebo and dutasteride.
The specialists conclude that effectiveness of 5?-reductase inhibitors can be limited in men who have normal or increased levels of testosterone. That’s why it is necessary to measure levels of testosterone in order to determine how bodies will respond to 5 ?-reductase inhibitors.
So, the research has demonstrated that muscle mass is not affected by 5?-reductase inhibitors.  Men have to know that if they have high levels of testosterone or introduce exogenous testosterone in their bodies, 5?-reductase inhibitors will not cause shrunken prostate.