Introduction: Anabolic-androgenic steroids (AASs) are a complex cluster of synthetic derivatives of testosterone. AAS abuse is considered a major public health issue since it has increased among young/adolescent males. The use of steroids has a prevalence rate of 14% in young athletes and 30-75% in professional athletes or bodybuilders. AASs simulate the testosterone mechanism, binding the intracellular androgen receptor, and dysregulating the normal hypothalamic-pituitary-gonadal axis in the same way as exogenous testosterone. Abuse can produce several side effects on organs, such as the genital system. The physio-pathological mechanisms that cause AAS abuse-related, genital system disorders in humans are still not completely known.

Evidence acquisition: This study focuses on the effect of AASs on the male reproductive organs in humans and animals.

Evidence synthesis: A systematic review was performed using SCOPUS, PubMed, Google Scholar, and Web of Sciences database up to 31 December 2021 using the keywords: "anabolic-androgenic steroids," "erectile dysfunction," "spermatogenesis" and "infertility;" (anabolic agents) "erectile dysfunction," "spermatogenesis" and "infertility." The review of the literature identified 66 articles published until 2021. Sixty-two articles were included. The use of AASs induces testicular atrophy and azoospermia known as "anabolic steroid-induced hypogonadism." Anabolic steroid induced infertility is characterized by oligo or azoospermia and abnormalities in sperm motility and morphology. Although sperm quality recovers in most cases within 4 months of stopping anabolic steroid abuse, the negative consequences on spermatogenesis can take up to 3 years to disappear. Human studies reported a positive correlation between AAS abuse in athletes and an increase in morphologically abnormal spermatozoa. Animal studies showed the destruction of Leydig cells and testicular atrophy in animals treated with cycles of AASs.

Conclusions: The present review of the literature highlights how little is known about the action of AASs on the male genital system. However, although their use is prohibited in many countries, the black market for these substances is still very frequent. The scientific landscape still has a lot to invest in the research of AAS on the male genital system to make young people even more aware of the negative aspects of these substances, contributing to the reduction of these products in an inappropriate way.