Androstenedione is a "pre-hormone," meaning that it is an inactive precursor of another hormone – in this case, a precursor of both female (estrogen) hormones and male (testosterone) hormones.
Supplement makers claim that a 100-milligram dose of androstenedione increases testosterone levels by 300% over a duration of 2-4 hours
In the body, "andro" becomes active upon conversion to testosterone - the major "male" hormone responsible for muscle growth and other male characteristics such as growth of facial hair and development of a deep voice. Higher levels of testosterone are thought to help athletes exercise more intensely and recover faster. Use of andro is banned in some sports, but not others. It is widely assumed that andro may be consumed by some athletes in order to "mask" the fact they are also taking anabolic steroids such as testosterone.
Unfortunately, there is not been a lot of credible research conducted on androstenedione as a dietary supplement. A recent study published in the Journal of the American Medical Association, however, concluded that androstenedione "does not increase serum testosterone concentrations of enhance skeletal muscle adaptations to resistance training" in young men with normal testosterone levels. The study found no augmentation of muscle size or strength when weight lifters used andro or a placebo pill. Of serious concern is the finding that andro supplements of 300 mg 3 times per day lowered blood levels of the "good" HDL cholesterol and increased levels of the “bad” LDL cholesterol (both by about 12%) and increased blood levels of two other hormones, estradiol and estrone, which have been associated with cardio vascular disease and breast cancer in women and pancreatic cancer in men. Although andro supplements increased androstenedione levels in the blood, there was no effect of short term or chronic intake on testosterone levels, muscle strength, muscle size
In one study, an open-label randomized design was used to investigate the effect of androstenedione supplements in 42 healthy men (20-40 years old). Subjects received either 100 mg/d (15 subjects) or 300 mg/d (14 subjects) of androstenedione, while 13 subjects were used as controls (receiving no androstenedione) for 7 days. Results showed that levels of testosterone in the blood were significantly higher (compared to the control group) in subjects consuming the 300mg, but not the 100mg dose of androstenedione. Interestingly, blood levels of estradiol (estrogen) were also significantly elevated in these young men by both the 100mg and 300 mg doses of androstenedione.
In a similar study, 20 young men (aged 19-29 years) performed 8 weeks of whole-body resistance training and consumed either 300mg/day of androstenedione or a placebo. In another portion of the study, another 10 young men received a single 100mg dose of androstenedione to determine the effects on serum testosterone and estrogen concentrations. Results showed that blood levels of testosterone were not affected by short- or long-term androstenedione consumption, but blood levels of estradiol were increased by more than 50% compared with pre-supplementation values. Following 8 weeks of androstenedione consumption there were no differences between the placebo and androstenedione groups in terms of muscle strength, lean body mass or fat mass. In the androstenedione group, however, blood levels of high-density lipoprotein (HDL) cholesterol (the “good” kind) was reduced after 2 weeks and remained low after 5 and 8 weeks of training and supplementation. The overall conclusions of the study were that, androstenedione supplementation does not increase serum testosterone concentrations or enhance muscle strength (in young men with normal testosterone levels) – but that it may result in adverse health consequences (increased estrogen levels and reduced HDL).
Although no long-term studies have been conducted on the safety of andro as a dietary supplement, there is a fairly substantial body of literature concerning the adverse effects associated with other anabolic steroids such as testosterone. In particular, prolonged use of steroids can result in a number of dangerous side effects such as blood lipid abnormalities (elevated LDL and reduced HDL cholesterol) which may increase the risk of heart disease, promotion of hormone-sensitive cancers such as breast and prostate cancer and various liver abnormalities.
The psychological effects of anabolic steroid use are well-known and include increased aggression (‘roid rage), depression and psychosis. From an appearance standpoint, steroid use will almost certainly result in increased muscle mass - provided the right exercise program is being followed. On the down-side, however are other cosmetic changes such as acne, hair loss (baldness) and hair growth (back), reduced testicle size and breast growth in men. In teenagers, steroid use could fool the body into shutting off its normal hormone production and causing stunted growth.
Despite the clear evidence against anabolic steroid use in general, many andro manufacturers claim that since no safety studies have been conducted specifically on andro, we should not assume that it has the same adverse effects as excessive testosterone levels. The findings of adverse alterations in blood lipid profile, however, should be reason enough for intelligent consumers to avoid dietary supplements containing androstenedione unless specifically recommended by a nutritionally-oriented physician.
Due to the lack of positive research findings and the potential for serious health risks from anabolic steroids and altered hormone profiles, androstenedione supplements should be considered to be of low value as a dietary supplement for healthy individuals.
Typical dosage recommendations are in the range of 50-200mcg NOTE: Competitive athletes should be aware of the potential for Androstenedione supplementation to alter the testosterone-epitestosterone ratio so it exceeds the 6:1 limit set by both the International Olympic Committee (IOC) and NCAA in their screening for testosterone doping.