What is it?
Androstenedione or "Andro" is a hormonal substance that is metabolized into testosterone once it's in the body.
Does it occur naturally in the body?
Yes, but only in very small quantities.
What are the claims?
Androstenedione converts into testosterone in the body, which then helps your body increase muscle mass and become more lean.
Does it work?
Two studies have shown that orally administered androstenedione does increase serum testosterone levels. Strangely it also increased estrogen levels as well. Unfortunately there was no difference in muscle mass for the group taking androstenedione and the control group at the conclusion of either study.
(The studies are King et.al. (JAMA 1999; 281: 2020-2028) and Leder et.al. (JAMA 2000; 283: 779-782))
The authors of both studies point out the following;
...with higher doses and more frequent administration as may characterize use by those interested in performance enhancement, "...it is likely that some individuals may experience sustained and larger increases in testosterone levels..." In addition, they speculate based on their data that differential metabolism to androgens and estrogens across individuals may predispose some to more androgenic responses and others to more estrogenic responses to androstenedione administration.
So in the studies no... but potentially yes. Androstenedione did not live up to it's billing as a product that can increase muscle mass in the King et.al. and Leder et.al. studies, but it might have androgenic (muscle building) qualities if given in higher doses and administered more frequently. Unfortunately we have not been able to find any further studies to prove this hypothesis.
What are the dangers?
Subjects who took androstenedione saw a 12% drop in their HDL cholesterol (the good kind). That kind of drop could very likely increase the risk of heart disease in longtime users.
DANGERS FOR MEN: Testicular atrophy, impotence and the development of female characteristics such as breast enlargement.
DANGERS FOR WOMEN: The development of male characteristics such as male pattern baldness, deepening of the voice, increased facial hair, and enlargement of the clitoris, as well as abnormal menstrual cycle and abnormal bleeding and blood clots. Women may also be at increased risk for breast cancer and endometrial cancer.
CHILDREN AND ADOLESCENTS: Androgenic and estrogenic effects as in adults, for early onset puberty and for premature cessation of growth, such that they will be short as adults.
Without long term studies to rely upon, scientists can only make educated guesses on what other problems may occur. However, it is possible that if a man took androstenedione long enough, the elevated estrogen levels would cause him to grow breasts (gynecomastia). That fact alone would probably stop andro sales cold if it were on a warning level.
The Bottom Line
There does not appear to be any benefit for bodybuilders, with no study showing any significant increase in muscle mass because of androstenedione. In addition there are potentially serious side effects.
Unless prescribed by a doctor for a medical condition, we cannot recommend the supplement androstenedione.
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