Anabolic steroids have been associated with many undesirable or adverse effects in laboratory and therapeutic studies. The most relevant effects are those that occur in the liver, as well as in the cardiovascular system, reproductive system and the psychological state of individuals using anabolic steroids.

Adverse liver effects – An excretory dysfunction of the liver resulting in jaundice has been associated with the use of anabolic steroids in a number of tertiary studies. The possible cause-effect relationship of this association is reinforced by the observation of the remission of jaundice after discontinuation of the drug. In studies of athletes who used anabolic steroids, no evidence of cholestasis was found.

Structural alterations of the liver were found as a consequence of treatment with steroids in animals and in humans. There are no conclusions about the clinical importance of these changes in the short or long term. Studies in athletes to evaluate these changes have not yet been performed, but there is no reason to believe that athletes who use anabolic steroids are immune to these undesirable effects.

The most serious hepatic complications associated with anabolic steroids are hepatic peliosis (blood-filled liver cysts of unknown etiology) and liver tumors. Cases of hepatic peliosis have been reported in individuals undergoing anabolic steroid treatment for a number of reasons. Cysts rupture or hepatic insufficiency was fatal in some individuals. In other case reports, this condition was a necropsy finding. The possible cause-effect relationship between hepatic peliosis and the use of anabolic steroids is reinforced by the observation of its improvement with the interruption of the use of these drugs in some cases. There are no reported cases of this condition in athletes who use anabolic steroids, but specific studies for this complication have not been performed in athletes.

Hepatic tumors have been associated with the use of anabolic steroids in individuals undergoing clinical treatment with these drugs. These tumors are generally benign, but malignant lesions associated with the use of these drugs have been observed. The possible cause-effect relationship of this association between steroid use and tumor development is reinforced by the report of tumor regression following discontinuation of steroid therapy. There is one reported case of a 26-year-old bodybuilder who died of hepatic neoplasm after using several types of anabolic steroids for at least four years. The examinations necessary for the detection of these tumors are not usually performed and it is possible that other tumors associated with the use of steroids by athletes remain undiagnosed.

There have been reports that liver function tests are unchanged with the use of steroids in some studies involving training and altered in other similar studies and in tests performed on athletes who were known to be using anabolic steroids. However, hepatic peliosis lesions and liver tumors do not always produce abnormalities in these exams and some authors maintain that hepatic scintigraphy, ultrasonography or computed tomography for this diagnosis are required.

In summary, hepatic function tests have been shown to be altered by anabolic steroids. The short- and long-term consequences of these changes, while potentially deleterious, are still to be reported in athletes who use these drugs.

Adverse effects on the cardiovascular system – Among the changes induced by anabolic steroids that may predispose to the development of cardiovascular diseases, we may include hyperinsulinism and an impaired glucose tolerance, a reduction cholesterol levels and an increase in blood pressure. These effects vary from one individual to another in different clinical situations. In some individuals who use anabolic steroids, triglycerides are reduced increasing in others. Histological analysis of myofibrils and myocardial mitochondria of laboratory animals have shown that the administration of anabolic steroids produces pathological alterations in these structures. Although the cardiovascular effects of anabolic steroids are potentially deleterious, more research is needed before any conclusions can be drawn.

Adverse effects to the male reproductive system – The effects of anabolic steroids on the male reproductive tract include oligospermia (reduction of sperm count), azoospermia (absence of sperm in semen), reduction of testicle size, abnormalities found in testicular biopsy, and reduction levels of testosterone and gonadotropic hormones. These effects were demonstrated in studies involving training, studies with healthy volunteers, therapeutic studies, and studies with athletes who were using anabolic steroids. Observing the changes that occur in the pituitary-gonadal axis, it is believed that the dysfunction occurs due to suppression of steroid-induced gonadotrophin production. Changes in these hormones are usually reversible after discontinuation of treatment, but the long-term effects of this hypothalamic-pituitary-gonadal axis disorder remain unknown. However, there are reports of residual abnormalities in the testicular morphology of healthy men six months after discontinuation of steroids. It has been reported that the metabolism of androgens in estrogenic compounds can lead to gynecomastia in men.

Adverse effects on the female reproductive tract – The effects of androgenic steroids on the female reproductive tract include the reduction of circulating levels of luteinizing hormone, follicle-stimulating hormone, estrogens and progesterone; inhibition of folliculogenesis and ovulation; and changes in the menstrual cycle which include follicular phase extension, shortening of the luteal phase and amenorrhea.

Adverse effects in the psychological sphere – In both sexes, the psychological effects of anabolic steroids include increases or decreases in libido, mood changes and aggressive behavior, which are related to plasma testosterone levels. Steroid administration produces electroencephalogram changes similar to those produced by psychostimulant drugs. Consideration should be given to the possible consequences of uncontrollably aggressive and possibly unfriendly behavior prior to the use of anabolic steroids.

Other adverse effects – Other adverse effects associated with anabolic steroids include: ataxia; premature closure of the growth plate in adolescents; virilization in adolescents and women, including hirsutism, clitoromegaly and irreversible aggravation of voice; acne; and alopecia. These adverse reactions may occur with the use of anabolic steroids and are believed to be dependent on the type of steroid, dose and duration of use15. There is no method that predicts which individuals would be more likely to develop these adverse effects, some of which are potentially deleterious.