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Androstenedione, andro for short, is a steroid hormone naturally produced in both men and women.
Androstenedione produced in the body is converted to either testosterone or to an estrogen. It
was widely available
as a dietary supplement and primarily marketed to athletes and bodybuilders in the belief that taking it will
increase strength, stamina and muscle mass.
Androstenedione is synthesized in the adrenal gland and gonads from
dehydroepiandrosterone (DHEA). It is metabolized
by the enzyme 17 beta-hydroxy steroid dehydrogenase to testosterone, and by the aromatase enzyme complex to estrone.
Estrone is metabolized to estradiol.
Androstenedione was classified as a dietary supplement under the Dietary Supplement Health and Education Act of
1994 up until mid 2004. The once over the counter dietary supplement is
no longer available.
MGH research shows androstenedione can raise testosterone levels
A study led by researchers from the Massachusetts General Hospital (MGH) has found that 300 milligram (mg)
doses of androstenedione
can raise blood testosterone levels in healthy young men. The report, in the Feb. 9 issue of the Journal of the
American Medical Association also showed an increase in estrogen levels with both 100 and 300 mg doses. It did not
examine whether taking androstenedione increases strength or muscle mass or whether androstenedione has long-term
side effects.
The MGH-led study was designed only to test the claim that taking oral androstenedione supplements would raise
testosterone levels. The research team led by Benjamin Leder, MD, also of the MGH Endocrine Unit enrolled 42
healthy men aged 20 to 40 with no previous history of taking androstenedione, steroids or any medication known to
affect steroid levels. Participants were divided randomly into three groups: 15 received 100 mg daily doses of
androstenedione, 14 received 300 mg doses of androstenedione, and 13 received no androstenedione. During the
seven-day study, blood tests taken at frequent intervals after participants took the capsules measured levels of
four hormones: androstenedione, testosterone and the estrogens estrone and
estradiol.
While the 100 mg doses had no significant effect on testosterone levels, the 300 mg doses increased testosterone
levels by an average of 34 percent. In one-third of those taking the 300 mg doses, testosterone levels exceeded the
normal range for men. Testosterone levels returned to normal within a day of androstenedione administration. Estrogen
levels also increased in both the 100 and 300 mg groups: estrone increased 74 percent at 100 mg and 196 percent at
300 mg, and estradiol increased 42 percent at 100 mg and 128 percent at 300 mg.
While this study examined only the direct effect of androstenedione on hormone levels, the authors noted that
long-term increases in testosterone or estrogen can have serious side effects in certain susceptible patient
populations. Elevated testosterone levels can lower levels of HDL (or "good") cholesterol and can have masculinizing
effects on women. Men with increased estrogen levels can experience feminizing effects such as the growth of breasts.
Young people who have elevated levels of either hormones could develop early puberty and a premature cessation of bone
growth, leading to shorter-than-normal adult height.
The authors also note that the effects of androstenedione were different for different individuals. Some
participants developed higher or lower hormone levels, suggesting that certain people may be more or less
sensitive to the hormonal effects of
androstenedione.
It has been claimed that supplemental androstenedione can significantly increase blood testosterone levels and
therefore build muscle mass. Recent research is conflicting with respect to the testosterone effect, but is unified
in suggesting that prolonged use of this steroid could result in serious health risks.
Some have suggested that more research is also needed to determine whether androstenedione may have some
usefulness in those with low and declining testosterone levels, such as some women and older men. There is some
evidence that supplementation with the steroid in doses under 300 milligrams a day might increase serum testosterone
levels in those who are hypotestosterogenic.
Pharmacology
The marketed supplement is synthetic. It is a solid lipophilic substance nearly insoluble in water.
Ingredients:
4-androstene-3,17-dione
Precautions
Children, adolescents, pregnant women and nursing mothers should avoid androstenedione supplements.
Potential
Side Effects
No data are available on the long-term safety of taking supplemental androstenedione.
Adverse effects of exogenous testosterone in men include acne, testicular atrophy, gynecomastia, behavioral
changes and possibly an increased risk of prostate cancer. Adverse effects of exogenous testosterone in women
include hirsutism, deepening of the voice, acne, clitoral hypertrophy, amenorrhea, male-pattern baldness and
coarsening of the skin. In adolescents, exogenous testosterone can lead to early closing of bone growth plates
and decreased adult height. Other adverse effects of testosterone include hepatic failure and increased platelet
aggregation.
References
King DS, Sharp RL, Vukovich MD, et al. Effect of oral androstenedione on serum testosterone and adaptations
to resistance training in young men. A randomized controlled trial. J Am Med Assoc. 1999; 281:2020-2028.
Leder BZ, Longcope C, Catlin DH, et al. Oral androstenedione administration and serum testosterone
concentrations in young men. J Am Med Assoc. 2000; 283:779-782.
Rasmussen BB, Volpi E, Gore DC, Wolfe RR. Androstenedione does not stimulate protein metabolism anabolism
in young healthy men. J Clin Endocrin Metab. 2000; 85:55-59.
Wallace MB, Lim J, Cutler A, Bucci L. Effects of dehydroepiandrosterone vs. androstenedione supplementation
in men. Med Sci Sports Exerc. 1999; 31:1788-1792.
Yesalis III CE. Medical, legal, and social implications of androstenedione use. J Am Med Assoc.
1999; 281:2043-2044.
Morales, A., et. al.,
Is Yohimbine Effective in the Treatment of Organic Impotence? Results of a
Controlled Trial, Journal of Urology, Vol. 137, June, 1987.
Reid, K., et. al.,
Double-Blind Trial of Yohimbine in Treatment of Psychogenic Impotence,
Lancet, August 22, 1987.
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