Various AAS and related compounds.
Since the discovery and synthesis of testosterone in the 1930s, AAS have been used by physicians for many purposes, with varying degrees of success. These can broadly be grouped into anabolic, androgenic, and other uses.
Bone marrow stimulation: For decades, AAS were the mainstay of therapy for
anemias due to
kidney failure, especially
 AAS have largely been replaced in this setting by synthetic protein hormones (such as
epoetin alfa) that selectively stimulate growth of
blood cell precursors.
Growth stimulation: AAS can be used by
pediatric endocrinologists to treat children with
 However, the availability of synthetic
growth hormone, which has fewer side effects, makes this a secondary treatment.
- Stimulation of
appetite and preservation and increase of
muscle mass: AAS have been given to people with
chronic wasting conditions such as
- Stimulation of lean body mass and prevention of
bone loss in elderly men, as some studies indicate.
 However, a 2006 placebo-controlled trial of low-dose testosterone supplementation in elderly men with low levels of testosterone found no benefit on body composition, physical performance,
insulin sensitivity, or
quality of life.
- Prevention or treatment of
Nandrolone decanoate is approved for this use.
 Although they have been indicated for this indication, AAS saw very little use for this purpose due to their virilizing side effects.
Androgen replacement therapy for men with
low levels of testosterone; also effective in improving libido for elderly males.
- Induction of male
puberty: Androgens are given to many boys distressed about extreme
delay of puberty. Testosterone is now nearly the only androgen used for this purpose and has been shown to increase height, weight, and fat-free mass in boys with delayed puberty.
Masculinizing hormone therapy for
transgender men, other
transmasculine people, and
intersex people, by producing masculine secondary sexual characteristics such as a
voice deepening, increased bone and muscle mass,
masculine fat distribution, facial and body hair, and
clitoral enlargement, as well as mental changes such as alleviation of
gender dysphoria and increased sex drive.
- Treatment of
breast cancer in women, although they are now rarely used for this purpose due to virilizing side effects.
- In low doses as a component of
hormone therapy for
transgender women, for instance to increase
quality of life, as well as to reduce
 Testosterone is usually used for this purpose, although
methyltestosterone is also used.
Male contraception, in the form of
testosterone enanthate; potential for use in the near-future as a safe, reliable, and reversible male contraceptive.
Numerous vials of injectable AAS
Most steroid users are not athletes.
 Between 1 million and 3 million people (1% of the population) are thought to have used AAS in the United States.
 Studies in the United States have shown that AAS users tend to be mostly middle-class
heterosexual men with a
median age of about 25 who are noncompetitive bodybuilders and non-athletes and use the drugs for cosmetic purposes.
 "Among 12- to 17-year-old boys, use of steroids and similar drugs jumped 25 percent from 1999 to 2000, with 20 percent saying they use them for looks rather than sports, a study by insurer Blue Cross Blue Shield found."(Eisenhauer) Another study found that non-medical use of AAS among college students was at or less than 1%.
 According to a recent survey, 78.4% of steroid users were noncompetitive bodybuilders and non-athletes, while about 13% reported unsafe injection practices such as reusing needles, sharing needles, and sharing multidose vials,
 though a 2007 study found that sharing of needles was extremely uncommon among individuals using AAS for non-medical purposes, less than 1%.
 Another 2007 study found that 74% of non-medical AAS users had post-secondary degrees and more had completed college and fewer had failed to complete high school than is expected from the general populace.
 The same study found that individuals using AAS for non-medical purposes had a higher employment rate and a higher household income than the general population.
 AAS users tend to research the drugs they are taking more than other controlled-substance users; however, the major sources consulted by steroid users include friends, non-medical handbooks, internet-based forums, blogs, and fitness magazines, which can provide questionable or inaccurate information.
AAS users tend to be unhappy with the portrayal of AAS as deadly in the media and in politics.
 According to one study, AAS users also distrust their physicians and in the sample 56% had not disclosed their AAS use to their physicians.
 Another 2007 study had similar findings, showing that, while 66% of individuals using AAS for non-medical purposes were willing to seek medical supervision for their steroid use, 58% lacked trust in their physicians, 92% felt that the medical community's knowledge of non-medical AAS use was lacking, and 99% felt that the public has an exaggerated view of the side-effects of AAS use.
 A recent study has also shown that long term AAS users were more likely to have symptoms of
muscle dysmorphia and also showed stronger endorsement of more conventional male roles.
 A recent study in the Journal of Health Psychology showed that many users believed that steroids used in moderation were safe.
AAS have been used by men and women in many different kinds of professional sports to attain a competitive edge or to assist in recovery from injury. These sports include
shot put and other
track and field,
mixed martial arts,
cricket. Such use is prohibited by the rules of the governing bodies of most sports. AAS use occurs among adolescents, especially by those participating in competitive sports. It has been suggested that the prevalence of use among high-school students in the U.S. may be as high as 2.7%.
 Male students used AAS more frequently than female students and, on average, those that participated in sports used steroids more often than those that did not.
A vial of injectable testosterone cypionate
There are four common forms in which AAS are administered: oral pills; injectable steroids; creams/gels for topical application; and skin patches. Oral administration is the most convenient. Testosterone administered by mouth is rapidly absorbed, but it is largely converted to inactive metabolites, and only about one-sixth is available in active form. In order to be sufficiently active when given by mouth, testosterone derivatives are alkylated at the 17α position, e.g.
fluoxymesterone. This modification reduces the liver's ability to break down these compounds before they reach the systemic circulation.
Testosterone can be administered
parenterally, but it has more irregular prolonged absorption time and greater activity in muscle in
ester form. These derivatives are hydrolyzed to release free testosterone at the site of injection; absorption rate (and thus injection schedule) varies among different esters, but medical injections are normally done anywhere between semi-weekly to once every 12 weeks. A more frequent schedule may be desirable in order to maintain a more constant level of hormone in the system.
 Injectable steroids are typically administered into the muscle, not into the vein, to avoid sudden changes in the amount of the drug in the bloodstream. In addition, because estered testosterone is dissolved in oil, intravenous injection has the potential to cause a dangerous
embolism (clot) in the bloodstream.
Transdermal patches (adhesive patches placed on the skin) may also be used to deliver a steady dose through the skin and into the bloodstream. Testosterone-containing creams and gels that are applied daily to the skin are also available, but absorption is inefficient (roughly 10%, varying between individuals) and these treatments tend to be more expensive. Individuals who are especially physically active and/or bathe often may not be good candidates, since the medication can be washed off and may take up to six hours to be fully absorbed. There is also the risk that an intimate partner or child may come in contact with the application site and inadvertently dose himself or herself; children and women are highly sensitive to testosterone and can suffer unintended masculinization and health effects, even from small doses. Injection is the most common method used by individuals administering AAS for non-medical purposes.
The traditional routes of administration do not have differential effects on the efficacy of the drug. Studies indicate that the anabolic properties of AAS are relatively similar despite the differences in pharmacokinetic principles such as
first-pass metabolism. However, the orally available forms of AAS may cause
liver damage in high doses.
Examples of AAS
Chemical structure of the synthetic steroid
(Dianabol). 17α-Methylation (upper-right corner) enhances oral
The AAS that have been used most commonly in medicine are
testosterone and its many
esters (but most typically
testosterone cypionate, and
nandrolone decanoate and
 Others that have also been available and used commonly but to a lesser extent include
oxymetholone, as well as
drostanolone propionate (dromostanolone propionate),
metenolone (methylandrostenolone) esters (specifically
metenolone acetate and
metenolone enanthate), and
Dihydrotestosterone (DHT), known as androstanolone or stanolone when used medically, and its
esters are also notable, although they are not widely used in medicine.
Boldenone undecylenate and
trenbolone acetate are used in
Designer steroids are AAS that have not been approved and marketed for medical use but have been distributed through the black market.
 Examples of notable designer steroids include
Boldenone undecylenate (vet)
||Aveed, Andriol, Nebido
Trenbolone acetate (vet)