Anabolic-androgenic steroids (AAS) have for years been the most used substances for improving muscle strength, mass and performance. Most users are not competitive athletes, and unfortunately a portion of the users are teenagers.
When using steroids, users try to maximize the anabolic (tissues growth stimulating) effect and minimize the androgenic (male type) effect. The anabolic/androgenic ratio of testosterone is one to one. In actual anabolic steroids, this ratio varies and can be even over 30.
It is not possible to avoid androgyny but it is strongly dependent on the dosage and how long steroids are used . To maximize the desired effects and avoid side effects, other hormone preparations are usually used simultaneously to help, for example, in preventing breast growth.
Anabolic androgens have a significant effect on gonadal function. The effects are individual-specific: in some users sperm production ceases totally and in others the changes are minor.
Testicular function and disturbances
The function of the testicles is to produce sperm and sex hormone, in other words testosterone. Normal testosterone production generates masculine sexual characteristics and ensures high testosterone level in testes (about a 100 times larger concentration than in blood circulation) that is indispensable for normal sperm production.
The functioning of the testicles is controlled by hypophysis. Anabolic androgens prevent the normal functioning of the hypophysis. The testicles’ own testosterone production and concentration decrease and, as a consequence, sperm production decreases and may cease totally.
The effect of anabolic androgens on sperm production is well-known among physicians who treat childlessness. According to studies, about one fourth of the users of anabolic steroids had no sperm production, in about half the sperm production was worse than normally, and only one fourth had normal sperm production [2, 3]. Anabolic steroids also have an effect on the structure of sperm cells.
The changes that androgens cause in sperm production are usually reversible. However, it can take a year before normal sperm cell amounts reappear after the use of large doses. No exact information exists on how using anabolic androgens before puberty affects testicular function in adulthood. In this sensitive phase, anabolic androgens can cause several, possibly irreversible, changes in testicular function.
Effect of anabolic androgens to sexual desire
Sexual desire (libido) is mostly controlled by testosterone. Anabolic steroids can increase the libido. The increased libido may be a problem because large androgen doses may also increase violence.
A more common problem is that the body's testosterone production usually ceases for several months after using steroids. Then the testosterone concentration in blood circulation is insufficient for normal libido and the hormone imbalance causes sexual apathy.
Very low testosterone concentrations may also cause erection problems. When simultaneously, for example, a weightlifter's results get significantly worse, the need to begin a new androgen cure is usually significant .
Examination of the effects and their treatment
Anabolic-androgenic steroids prevent the normal functioning of the hypophysis. A similar effect occurs in women with combination birth-control pills. Users are very aware of the problems caused by anabolic steroids and some of them seek medical care and visit a doctor, but they won’t necessarily initiate a discussion about their use.
Besides the typical appearance, other apparently abnormal things are not always found in the medical examination. The side effects (for example acne, skin stretching scars, breast growth, and possible marks of injections) related to the androgen treatment may be seen. As a result of prolonged androgen use testicles may be really small.
The effect of anabolic androgens on fertility function depends remarkably on the preparations used, doses and how long they are used. In hormone tests depicting testicular function typical anomalies are found. In most cases, the total lack of sperm cells is found in semen examinations. In some of the users, the anomaly is smaller.
The changes caused by anabolic androgens are reversible, but the recovery of sperm production can take as long as a year. In most cases, the most efficient and effective treatment is stopping the use of anabolic androgens. A precondition for treatment success is the individual understanding of the factual connections and knowing that it takes time to recover . Motivating the user is important.
Maintenance of physiological testosterone concentrations (i.e. testosterone replacement treatment) may be necessary in the recovery phase if the hypofunction has been severe and prolonged. However, there is a possibility for the risk of abuse. The replacement treatment prolongs the sperm production recovery.
The use of anabolic steroids doesn’t exclude other reasons for male infertility. If the findings don’t appear to be caused by anabolic androgens or if the changes don’t return to normal after stopping the use of AAS, other reasons for the bad sperm should be considered.
M.D. h.c., Docent
Reproductive Medicine and Andrology
Specialist Doctor of Gynecopathies, the Department of Obstetrics and Gynecology in Turku University Hospital
Biomedical department/Physiology, University of Turku
 Evans (2004): Current concepts in anabolic-androgenic steroids. American Journal of Sports Medicine 32: 534-42.
 Karila & Hovatta & Seppälä (2004): Concomitant abuse of anabolic androgenic steroids and human chronionic gonadotrophin impairs spermatogenesis in power athletes. International Journal of Sports Medicine 25: 257-63.
 Torres-Calleja, Gonzales-Unzaga, DeCelis-Carrillo, Calzada-Sanchez & Pedron (2001): Effect of androgenic anabolic steroids on sperm quality and serum hormone levels in adult male bodybuilders. Life Science 68: 1769-74.
 Brower, Eliopulos, Blow, Catlin & Beresford (1990): Evidence for physical and psychological dependence on anabolic androgenic steroids in eight weight lifters. American Journal of Psychiatry 147: 510-2.
 Drakeley, Gazvani & Lewis-Jones (2004): Duration of azoospermia following anabolic steroids. Fertility and Sterility 81:226.