New studies have displayed that dutasteride doesn’t affect muscle mass caused by testosterone use

According to a trial, the 5-alpha reductase inhibitor dutasteride (Avodart) doesn’t affect fat-free mass in healthy males who take testosterone.
A study connected with this issue was performed. While fat-free mass was increased by 0,6-7,1 kg during 20 weeks in males who applied dutasteride and Testosterone Enanthate, fat-free mass was enhanced by 0,8-8,1 kg in those that 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 applied clinically for treatment of benign prostatic hyperplasia (BPH) and androgenic alopecia. These are disorders which commonly appear in middle-aged and old men.
DHT represents the chief metabolite of testosterone. But the role of DHT in human development is not is not understood. It is suggested that DHT plays vital role in development of prostate and phallus.
Middle-aged and old men with reduced testosterone levels that take testosterone drugs have risks connected with decreased muscle size and sexual disorders.
Scientists also study and develop nonsteroidal selective androgen receptor modulators (SARMs). It is claimed that SARMs and 5-alpha reductase inhibitors are safe because DHT is probably 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 some other factors.
Shalender Bhasin and his colleagues at the Boston University have performed a clinical trial in order to set whether 5?-reduction to DHT is needed in order to mediate androgen’s effects on muscle mass. Furthermore, the specialists evaluated role of 5?-reduction on sexual functions, hematocrit and levels of lipid.
The research conducted by Bhasin and his colleagues involved healthy males that were 18- 50 years old and had normal testosterone levels. They used Testosterone Enanthate and dutasteride or placebo. Measures of Testosterone Enanthate ranged from 50 to 600 mg per week.
Since 5 ?-reductase inhibitors enhance testosterone levels, all men were given also gonadotropin-releasing hormone agonist in order to block natural testosterone.
The results of the study displayed that fat-free mass was enhanced due to usage of testosterone. It didn’t differ substantially in men of these two groups. Muscle strength which was also increased due to administration of testosterone didn’t differ between the two groups too. Sexual activity, prostate volume, sebum production, hemoglobin, acne, hematocrit didn’t differ essentially between those who used placebo and dutasteride.
The scientists conclude that effectiveness of 5?-reductase inhibitors can 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 enhanced levels of testosterone or introduce exogenous testosterone in their bodies, 5?-reductase inhibitors will not cause shrunken prostate.