Androstenedione (popularly known
as Andro) is a natural hormone proven to increase testosterone levels. It is a natural substance found in humans, animals
and in the pollen from many plants. It is produced in the gonads and adrenal glands of all mammals. As a metabolite
of DHEA, it serves as a direct precursor in the bio-synthesis of testosterone. The oral form of
Androstenedione is metabolized, by a single liver enzyme, into testosterone.
is currently used as a nutritional supplement to grow bigger muscles and stronger bones. This implies that
androstenedione may have anabolic properties. Even though it has not been convincingly demonstrated yet that
androstenedione is an anabolic steroid, its anabolic properties are likely based on its proven ability to
increase testosterone levels. The role of testosterone in building stronger muscles and bones is widely accepted.
Thus, high doses of testosterone-boosting drugs combined with strength training have been shown to increase muscle
size and strength even in normal young men. This confirms what thousands of athletes who take anabolic steroids have
known for decades. Yet androstenedione is different from testosterone-boosting drugs in a number of important
aspects. To begin with, androstenedione is a naturally occurring substance that is produced by the body itself. In
contrast to synthetic anabolic steroids, androstenedione is right at home in the human body, and perfectly complements
the complex hormonal network in the body.
Even though much of the publicity on the use of androstenedione is
toward body builders and athletes, it is important to note that people over the age of 40 years claim great benefits by
boosting the amounts of testosterone in the body. The beneficial effect claims include enhanced libido, protection
against age-related diseases, such as heart and prostate disease, osteoporosis and muscle atrophy. Androstenedione
have also claimed to be effective in improving mood and energy levels.
a popular supplement taken to enhance athletic performance, did not enhance muscle-building or increase testosterone in
the blood but appeared to produce adverse health effects in a small study of young men, according to an article in a
recent issue of The Journal of the American Medical Association (JAMA).
Douglas S. King, Ph.D., of Iowa State University in Ames, and
colleagues studied 30 healthy men ages 19-29 with normal testosterone levels in a randomized controlled trial.
Twenty of the men performed eight weeks of whole-body resistance training.
During weeks one, two, four, five, seven and eight, 10 of the men were given 300 mg of androstenedione a day, and the
others were given a placebo.
The researchers discovered that muscle strength did not differ
between the placebo and androstenedione groups before training or after four and eight weeks of resistance
training and supplementation. They also found that testosterone levels in the blood were not affected by the
The researchers did find a significant lowering of high density
lipoprotein (HDL, or “good”) cholesterol in the blood in those receiving androstenedione. Also, certain estrogen
levels in the blood increased in the men taking the supplement. In men, increased blood estrogen levels are
associated with the development of gynecomastia (enlarged breasts), and increased risk of cardiovascular disease and
In an accompanying editorial, Charles E. Yesalis III, MPH, Sc.D.,
of Pennsylvania State University in University Park, writes:
“During the past year, the public was exposed to a barrage of drug scandals in sports. These involved Olympic champions
in track and field, swimming and snowboarding, as well as elite cyclists, a three-time winner of the Boston Marathon,
and a professional tennis player.
However, of all the drug-related stories in 1998, none received more
media attention than home run record holder Mark McGwire's admission that he used androstenedione as a
“When questioned, supporters of McGwire borrowed several pages
from today's political playbook and argued that what McGwire did was not illegal, was a personal matter, and, besides,
the quest for the home run record was good for baseball,” Yesalis continues. “Nevertheless, while androstenedione is
not outlawed in major league baseball, it is on the banned drug lists of the International Olympic Committee, the
National Football League and the National Collegiate Athletic Association. Many expressed concern that the use of
this agent by sports heroes, who may be considered role models, might encourage youngsters to use this steroid
hormone. This apprehension is supported, in part, by the claim by Barry McCaffrey, director of the Office of National
Drug Control Policy, that androstenedione use by youngsters has increased five-fold since McGwire's admission.
Yesalis writes that the authors of this new research have conducted
a well-designed study that has provided valuable information, but that several scientific questions remain
and indicate the need for further investigation.
“For example, of the young men enrolled, only two had ever
engaged in resistance training, and that training had been more than one year earlier. Such inexperienced weight
trainers generally make significant gains in the early phase of resistance training programs. These large strength gains
could overshadow, statistically, any potential gains from androstenedione.”
He adds: “Future studies may need to focus on the effects of a
higher dose of androstenedione administered during a period longer than eight weeks. While the study by King used a
daily dose of 300 mg, recent advertisements for androstenedione recommend a daily dose of 500 to 1200 mg.”
Yesalis concludes: “In the case of androstenedione, the study by
King contributes to the evidence suggesting that the government should carefully consider intervening and remove
androstenedione and its derivatives from the market.”
Known Negative Effects
Information about possible side effects and risks of androstenedione is
very limited. Also, recent studies show that the drug's actions don't support manufacturer's claims. While a few
individuals have shown increased levels of testosterone, most failed to achieve increases in blood testosterone
Initial medical research has raised concerns about this supplement's safety.
Doctors worry that androstenedione may increase the risk of heart disease or liver cancer. In addition, research also
associates androstenedione use with increases in estradiol, a female estrogen.
Athletes should consider the effect rapid testosterone increases have
on their personality. Androstenedione will not convert to estrogen (DHEA does) so there are no negative estrogenic
side effects possible. Androgens are the male sex steroids. They increase body hair, facial hair and acne; deepen the
voice; enhance prostate growth; and promote muscle growth. The best known androgen is testosterone. Too much androgen
shuts off the body's own production of testosterone. This can impair normal testicular function - "it shrinks
your grapes to raisins." The use of androgens is especially dangerous among adolescents in whom it is known
to stunt growth.
While it is almost impossible to take androstenedione without any side
effects, 100 mg per day seems to be the optimum dosage. Adolescents
should not take it at all because the boost in hormones are very harmful, and they normally have a higher level of
testosterone on a daily basis. It would be a waste of money for any one under 25 to take androstenedione, or any
prohormones for that matter. Most athletes take between 50 mg. and 300 mg. daily, depending upon the desired level of
gains and the time spent in the gym.