According to a trial, treatment with dutasteride (Avodart), a 5-alpha reductase inhibitor, doesn’t influence negatively on fat-free mass in healthy men who administer testosterone.
A study linked with this issue was conducted. While fat-free mass was enhanced by 0,6-7,1 kg during 20 weeks in males that applied dutasteride and Testosterone Enanthate, fat-free mass was increased by 0,8-8,1 kg in those that administered placebo and testosterone. As for muscle strength, sexual functions and volume of prostate, they didn’t differ in males of these two groups.
5-alpha reductase inhibitors are utilized clinically to treat benign prostatic hyperplasia (BPH) and androgenic alopecia. These are dysfunctions which commonly occur in middle-aged and elderly males.
DHT represents the chief metabolite of testosterone. But the function of DHT in human development is not studied well. It is supposed that DHT plays relevant role in development of prostate and phallus.
Middle-aged and elder men with reduced testosterone levels that take testosterone drugs have risks linked with reduced muscle size and sexual disorders.
Scientists also study and develop nonsteroidal selective androgen receptor modulators (SARMs). It is confirmed 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 plays 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 set whether 5?-reduction to DHT is required in order to mediate androgen’s effects on fat-free 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 implicated healthy men who were 18- 50 years old and had normal testosterone levels. They were given Testosterone Enanthate and dutasteride or placebo. Dosages of Testosterone Enanthate ranged from 50 to 600 mg per week.
Since 5 ?-reductase inhibitors enhance levels of testosterone, all men were given also gonadotropin-releasing hormone agonist in order to block natural testosterone.
The results of the research displayed that fat-free mass was enhanced due to application of testosterone. It didn’t differ essentially in men of these 2 groups. Muscle strength that was also enhanced due to administration of testosterone didn’t differ between the two groups too. Sexual functions, volume of prostate, sebum production, hemoglobin, acne, hematocrit didn’t differ substantially between those who took placebo and dutasteride.
The experts affirm that effectiveness of 5?-reductase inhibitors may be limited in males who have normal or increased testosterone levels. 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 study has manifested that muscle mass is not affected by 5?-reductase inhibitors. Men should know that if they have enhanced testosterone levels or introduce exogenous testosterone in their bodies, 5?-reductase inhibitors will not lead to shrinkage of prostate.