A March 2017 study published in The Journal of Sexual Medicine reveals for the first time the highly damaging effects of an entire class of drug compounds called 5-alpha reductase inhibitors. They are often used in medications prescribed to treat urogenital problems, especially in men suffering from an enlarged prostate or benign prostatic hyperplasia. They are also found in medicines against androgenic alopecia – male pattern baldness. Scientists at Boston University School of Medicine found that taking these compounds was directly linked to the development of severe erectile dysfunction, depression and a severe decrease in libido, even long after the medication was no longer taken. Less common ejaculatory disorders and reduced volume of ejaculate have also been reported. Over the last decade, the use of reductase inhibitors, which were recently recognized as dangerous, has steadily increased, being prescribed to more and more young men suffering from androgenic alopecia or enlarged prostate. Taking the compound is most harmful for them, because the developed sexual dysfunctions can have a long duration. NEWS_MORE_BOX The main pharmacologic problem of reductase inhibitors is a mechanism considered until a few months ago to be a “very rare side effect.” It is expressed in the inhibition or suppression of the synthesis of a compound extremely important for the central nervous system. It is a neurosteroid known as 5-alpha dihydrotestosterone. Its synthesis is most often carried out through the conversion of testosterone in the prostate gland, epididymis, skin, hair follicles, liver and brain. The synthesis and secretion of this testosterone-like neurosteroid is controlled by an enzyme called 5-alpha reductase. It is this enzyme that is suppressed by the 5-alpha reductase inhibitors such as dutasteride and finasteride, which are found in drugs such as Proscar, Propecia and Avodart.