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Anabolic Steroids

ByMasaya Jimbo, MD, PhD, Thomas Jefferson University Hospital
Reviewed/Revised Apr 2025 | Modified Jul 2025
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Anabolic steroids (also called anabolic androgenic steroids) are synthetic (man-made) versions of the hormone testosterone and related substances that are often used to increase muscle size and strength.

  • Anabolic steroids are hormones that promote muscle growth and increase strength and energy.

  • Anabolic steroids can also have many side effects, including psychologic (mood swings, aggressive behavior, irritability) and physical (acne, masculinizing effects in women; infertility and suppression of natural testosterone production, Anabolic steroids can also have many side effects, including psychologic (mood swings, aggressive behavior, irritability) and physical (acne, masculinizing effects in women; infertility and suppression of natural testosterone production,gynecomastia in men).

  • These substances can be detected in urine for up to 6 months.

  • Treatment of most of the side effects involves stopping use.

Anabolic steroids include the hormone testosterone and related drugs. Anabolic steroids have many physical effects, including promoting muscle growth and increasing strength and energy. Thus, these drugs are often used illegitimately to gain a competitive edge in sports. Users are often athletes. Approximately 2% of females and 6% of males worldwide use or abuse anabolic steroids, with similar estimates for the United States. These estimates apply to both adults and adolescents.

Anabolic steroids have many medical uses, including treating low testosterone levels (hypogonadism) and sometimes to prevent muscles from wasting away in people who are confined to bed or who have severe burns, cancer, or severe human immunodeficiency virus infection. However, using anabolic steroids purely to increase muscle size and strength, especially without a prescription, is considered abuse. In the United States, most anabolic steroids are regulated by the Controlled Substances Act, and it is illegal to possess them without a prescription.

The drugs may be taken by mouth, injected into a muscle, or applied to skin as a gel or in a patch.

Athletes may take steroids for a certain period, stop, then start again several times a year. This process is called cycling. Athletes also often use many steroids at the same time (a practice called stacking), and they take them by different routes (by mouth, injection, or patch). They may also increase the dose through a cycle (called pyramiding). Pyramiding may result in very high doses. Cycling, stacking, and pyramiding are intended to enhance desired effects and minimize harmful effects, but little evidence supports these benefits.

At doses used to treat medical disorders, anabolic steroids cause few problems. However, individuals may take doses 10 to 50 times these doses for their effects on muscle size and strength.

Symptoms and Signs of Anabolic Steroid Use

Anabolic steroids have physical and psychologic effects. The more drug is taken, the greater the effect.

Physical effects

The main physical effect of anabolic steroids is

  • Increased muscle size

Other physical effects include

  • Gynecomastia (breast enlargement) and shrunken testicles with decreased sperm count, and usually infertility, in men

  • Virilization (masculinizing effects) in women, such as baldness, excess body hair (hirsutism), an enlarged clitoris, a deepened voice, shrunken breasts, and thinning of the lining (atrophy) of the vagina

Gynecomastia in men and masculinizing effects in women may be irreversible.

Increased acne is common in both sexes. Aggressiveness and appetite may increase, especially with high doses. In younger adolescents, steroids can interfere with the development of arm and leg bones.

Long-term use can cause the body to produce too many red blood cells and abnormal levels of fats (lipids) in the blood. Low-density lipoprotein (LDL)—the bad—cholesterol levels increase, and high-density lipoprotein (HDL)—the good—cholesterol levels decrease. Severe cardiovascular complications, including high blood pressure,heart attack, and blood clots, are reported with the use of anabolic steroids. Complications affecting the liver or kidneys may also occur.

Psychologic effects

Steroids have several psychologic effects (usually only with high doses):

  • Wide and erratic mood swings

  • Irrational behavior

  • Increased aggressiveness (steroid, or "roid" rage)

  • Irritability

  • Increased sex drive (libido) in men and sometimes in women

  • Depression

Diagnosis of Anabolic Steroid Use

  • Urine tests

  • Blood tests

Urine tests are done to check for breakdown products of anabolic steroids. These products can be detected up to 6 months after use is stopped.

Blood tests can be performed to check the person's current level of testosterone and determine whether it is higher than normal. Blood levels of other reproductive hormones (such as follicle stimulating hormone [FSH], luteinizing hormone [LH]) can also be measured. If the testosterone is very high but the FSH and LH levels are low, this provides evidence that the person is using anabolic steroids.

Treatment of Anabolic Steroid Use

  • Stopping use of steroids

The main treatment is stopping use. Although physical dependence does not occur, psychologic dependence, particularly in competitive bodybuilders, may exist. Gynecomastia (enlarged breast tissue in men) may require surgical reduction.

Men who develop infertility as a result of anabolic steroid use may be given medications to help restore fertility.

Prevention of Anabolic Steroid Use

Adolescents and young adults should be taught about the risks of taking anabolic steroids starting in middle school. Also, programs that teach alternative, healthy ways to increase muscle size and improve performance may be useful. Such programs emphasize good nutrition and weight training techniques.

More Information

The following English-language resources may be useful. Please note that The Manual is not responsible for the content of these resources. 

  1. National Institute on Drug Abuse (NIDA): Anabolic Steroids and Other Appearance and Performance Enhancing Drugs (APEDs)

Drugs Mentioned In This Article

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