The term "anabolic steroids" refers to testosterone derivatives that are used either clinically or by athletes for their anabolic properties. However, scientists have questioned the anabolic effects of testosterone and its derivatives in normal men for decades. Most scientists concluded that anabolic steroids do not increase muscle size or strength in people with normal gonadal function and have discounted positive results as unduly influenced by positive expectations of athletes, inferior experimental design, or poor data analysis. There has been a tremendous disconnect between the conviction of athletes that these drugs are effective and the conviction of scientists that they aren't. In part, this disconnect results from the completely different dose regimens used by scientists to document the correction of deficiency states and by athletes striving to optimize athletic performance. Recently, careful scientific study of suprapharmacologic doses in clinical settings - including aging, human immunodeficiency virus, and other disease states - supports the efficacy of these regimens. However, the mechanism by which these doses act remains unclear. "Anabolism" is defined as any state in which nitrogen is differentially retained in lean body mass, either through stimulation of protein synthesis and/or decreased breakdown of protein anywhere in the body. Testosterone, the main gonadal steroid in males, has marked anabolic effects in addition to its effects on reproduction that are easily observed in developing boys and when hypogonadal men receive testosterone as replacement therapy. However, its efficacy in normal men, as during its use in athletes or in clinical situations in which men are eugonadal, has been debated. A growing literature suggests that use of suprapharmacologic doses can, indeed, be anabolic in certain situations; however, the clear identification of these situations and the mechanism by which anabolic effects occur are unclear. Furthermore, the pharmacology of "anabolism" is in its infancy: no drugs currently available are "purely" anabolic but all possess androgenic properties as well. The present review briefly recapitulates the historic literature about the androgenic/anabolic steroids and describes literature supporting the anabolic activity of these drugs in normal people, focusing on the use of suprapharmacologic doses by athletes and clinicians to achieve anabolic effects in normal humans. We will present the emerging literature that is beginning to explore more specific mechanisms that might mediate the effects of suprapharmacologic regimens. The terms anabolic/androgenic steroids will be used throughout to reflect the combined actions of all drugs that are currently available.
The use of drugs to enhance physical performance has been observed for thousands of years. Today, individuals continue to use a variety of substances, including anabolic-androgenic steroids, in the hope of enhancing their performance and appearance. Rumours persist regarding the incidence of the nonmedical use of anabolic steroids by athletes and nonathletes: however, true estimates are now available based on the results of systematic surveys. Although the vast majority of the athletic community accepts that anabolic steroids enhance performance and appearance, the extent to which this occurs and the factors influencing such effects remain incompletely understood and documented. Refinement of our knowledge of the ergogenic effects of anabolic steroids is not without merit; however, the existing scientific evidence coupled with an overwhelming number of anecdotal accounts argues against devoting significant resources to this area of investigation at present. The short term health effects of anabolic steroids have been increasingly studied and reviewed, and while anabolic steroid use has been associated with several adverse and even fatal effects, the incidence of serious effects thus far reported has been extremely low. The long term effects of anabolic steroid use are generally unknown. Unfortunately, the lack of scientific information on long term health effects has impeded, if not precluded, the formation of effective health education and drug abuse prevention strategies. Consequently, efforts should be expanded in the areas of prevention and education.