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Anabolic Steroids

by Patrick G. O’Connor, MD, MPH

Anabolic steroids are often used to enhance physical performance and promote muscle growth. When used inappropriately, chronically at high doses and without medical supervision, they can cause erratic and irrational behavior and a wide range of physical adverse effects.

Anabolic steroids include testosterone and any drugs chemically and pharmacologically related to testosterone that promote muscle growth; numerous drugs are available. Anabolic steroids are used clinically to treat low testosterone levels (see Male Hypogonadism). Additionally, because anabolic steroids are anticatabolic and improve protein utilization, they are sometimes given to burn, bedbound, or other debilitated patients to prevent muscle wasting. Some physicians prescribe them to patients with AIDS-related wasting or with cancer. However, there are few data to recommend such therapy and little guidance on how supplemental androgens may affect underlying disorders. Testosterone has been reputed to benefit wound healing and muscle injury, although few data support these claims.

Anabolic steroids are used illicitly to increase lean muscle mass and strength; resistance training and a certain diet can enhance these effects. There is no direct evidence that anabolic steroids increase endurance or speed, but substantial anecdotal evidence suggests that athletes taking them can perform more frequent high-intensity workouts. Muscle hypertrophy is unequivocal.

Estimates of lifetime incidence of anabolic steroid abuse range from 0.5 to 5% of the population, but subpopulations vary significantly (eg, higher rates for bodybuilders and competitive athletes). In the US, the reported rate of use is 6 to 11% among high school–aged males, including an unexpected number of nonathletes, and about 2.5% among high school–aged females.


Anabolic steroids have androgenic effects (eg, changes in hair or in libido, aggressiveness) and anabolic effects (eg, increased protein utilization, increased muscle mass). Androgenic effects cannot be separated from the anabolic, but some anabolic steroids have been synthesized to minimize the androgenic effects.

Testosterone is rapidly degraded by the liver; oral testosterone is inactivated too rapidly to be effective, and injectable testosterone must be modified (eg, by esterification) to retard absorption or delay breakdown. Analogs modified by 17α-alkylation are often effective orally, but adverse effects may be increased. Transdermal preparations are also available.

Chronic effects

Adverse effects vary significantly by dose and drug. There are few adverse effects at physiologic replacement doses (eg, methyltestosterone 10 to 50 mg/day or its equivalent). Athletes may use doses 10 to 50 times this range. At high doses, some effects are clear; others are equivocal (see Adverse Effects of Anabolic Steroids). Uncertainties exist because most studies involve abusers who may not report doses accurately and who also use black market drugs, many of which are counterfeit and contain (despite labeling) varying doses and substances.

Adverse Effects of Anabolic Steroids

Clearly shown


Abnormal lipid profile (decreased HDL, increased LDL)

Liver abnormalities: Peliosis hepatitis, adenoma

Mood disorders (with high doses)

Androgenic effects: Acne, baldness, virilization and hirsutism in females

Gonadal suppression (decreased sperm count, testicular atrophy)


Premature closure of epiphyses


Hypertension and LVH

Worsening of prostatic hypertrophy or preexisting carcinoma

Hepatic carcinoma

Poorly shown*

Increased risk of sudden death in athletes

Significant mood disorder with low doses

*Predominantly with 17α-alkylated analogs.

HDL = high-density lipoprotein; LDL = low-density lipoprotein; LVH = left ventricular hypertrophy.

Athletes may take steroids for a certain period, stop, then start again (cycling) several times a year. Intermittently stopping the drugs is believed to allow endogenous testosterone levels, sperm count, and the hypothalamic-pituitary-gonadal axis to return to normal. Anecdotal evidence suggests that cycling may decrease harmful effects and the need for increasing drug doses to attain the desired effect.

Athletes frequently use many drugs simultaneously (a practice called stacking) and alternate routes of administration (oral, IM, or transdermal). Increasing the dose through a cycle (pyramiding) may result in doses 5 to 100 times the physiologic dose. Stacking and pyramiding are intended to increase receptor binding and minimize adverse effects, but these benefits have not been proved.

Symptoms and Signs

The most characteristic sign is a rapid increase in muscle mass. The rate and extent of increase are directly related to the doses taken. Patients taking physiologic doses have slow and often unnoticeable growth; those taking megadoses may increase lean body weight by several pounds per month. Increases in energy level and libido (in men) occur but are more difficult to identify.

Psychologic effects (usually only with very high doses) are often noticed by family members:

  • Wide and erratic mood swings

  • Irrational behavior

  • Increased aggressiveness (“roid rage”)

  • Irritability

  • Increased libido

  • Depression

Increased acne is common in both sexes; libido may increase or, less commonly, decrease; aggressiveness and appetite may increase. Gynecomastia, testicular atrophy, and decreased fertility may occur in males. Virilizing effects (eg, alopecia, enlarged clitoris, hirsutism, deepened voice) are common among females. Also, breast size may decrease; vaginal mucosa may atrophy; and menstruation may change or stop. Virilization and gynecomastia may be irreversible.


  • Urine testing

A urine screen usually identifies users of anabolic steroids. Metabolites of anabolic steroids can be detected in urine up to 6 mo (even longer for some types of anabolic steroids) after the drugs are stopped. Testosterone taken exogenously is indistinguishable from endogenous testosterone. However, if high levels of testosterone are detected, the ratio between testosterone and epitestosterone (an endogenous steroid that chemically is nearly identical to testosterone) is measured. Normally, the ratio is < 6:1; if exogenous testosterone is being used, the ratio is higher.


  • Cessation of use

The main treatment is cessation of use. Although physical dependence does not occur, psychologic dependence, particularly in competitive bodybuilders, may exist. Gynecomastia may require surgical reduction.


Physicians caring for adolescents and young adults should be alert to the signs of steroid abuse and teach patients about its risks. Education about anabolic steroids should start by the beginning of middle school. Use of programs that teach alternative, healthy ways to increase muscle size and improve performance through good nutrition and weight training techniques may help.

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