New findings can alter attitude to dutasteride

According to a trial, treatment with dutasteride (Avodart), a 5-alpha reductase inhibitor, doesn’t influence negatively on muscle mass in healthy men that apply testosterone.
A research connected with this issue was performed. 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 were given 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 applied clinically to treat benign prostatic hyperplasia (BPH) and androgenic alopecia. These are dysfunctions that usually affect middle-aged and elderly males.
DHT represents the main metabolite of testosterone. But the role of DHT in human development is not is not understood. It is supposed that DHT has important role in development of prostate and phallus.
Middle-aged and elder men with reduced testosterone levels that use testosterone medications have risks connected with reduced muscle size and sexual disorders.
Specialists also put efforts to develop nonsteroidal selective androgen receptor modulators (SARMs). It is claimed that SARMs and 5-alpha reductase inhibitors are safe because DHT is supposedly not necessary for effects on fat-free mass, muscle power and sexual activity. It is also doubted whether DHT has 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 experts evaluated role of 5?-reduction on sexual activity, hematocrit and levels of lipid.
The research conducted by Bhasin and his colleagues involved healthy males who were 18- 50 years old and had normal levels of testosterone. They applied Testosterone Enanthate and dutasteride or placebo. Quantities of Testosterone Enanthate ranged from 50 to 600 mg per week.
Since 5 ?-reductase inhibitors enhance levels of testosterone, all males were given also gonadotropin-releasing hormone agonist in order to block natural testosterone.
The results of the research manifested that fat-free mass was increased due to usage of testosterone. It didn’t differ significantly in men of these 2 groups. Muscle power which was also enhanced due to application of testosterone didn’t differ between the two groups too. Sexual functions, volume of prostate, sebum production, hemoglobin, acne, hematocrit didn’t differ significantly between those who took placebo and dutasteride.
The experts affirm that effectiveness of 5?-reductase inhibitors can be limited in males that have normal or increased testosterone levels. That’s why it is important to check testosterone levels in order to determine how bodies will respond to 5 ?-reductase inhibitors.
So, the research has shown that muscle mass is not affected by 5?-reductase inhibitors.  Men have to know that if they have high testosterone levels or introduce exogenous testosterone in their bodies, 5?-reductase inhibitors will not cause shrinkage of prostate.