Androstenedione and its close cousins androstenediol, norandrostenedione, and others, are natural steroid hormones found in the body and available over the counter. There are several other steroid hormones available without a prescription, including DHEA and pregnenolone.
Basically, pregnenolone is the grandmother of all the steroid hormones. Pregnenolone is able to convert into DHEA, which in turn converts into Andro (short for androstenedione). The body can then convert Andro into testosterone and estrogens.
Steroid hormones are made mostly in the adrenal glands, testicles (in men), and ovaries (in women), but they can also be made in other parts of the body, including the brain, where they are called neurosteroids. Andro and testosterone are known as androgens, while DHEA is known as a pro-androgen since it converts into androgens.
Since Andro is the precursor to testosterone, there has been speculation that Andro has libido boosting properties. There has also been speculation that Andro is beneficial for muscle building.
Andro and Libido
I could not find any research regarding the role of Andro and sex drive. However, there have been countless studies supporting the role of other androgens, such as testosterone, in increasing sex drive and overall sexual enjoyment.
Androgens are known to enhance sexual thoughts and fantasies as well as enhance mood and well-being. Androgens facilitate the action of nitric oxide in causing genital swelling, and they also enhance the sensation of genital organs such as the clitoris and penis. It is possible that androgens also increase sensation of nipples.
Does Andro Build Muscles?
Some body builders anecdotally report that they notice increased strength on the days they work out when they use androstenedione. A highly publicized study indicates that androstenedione may not live up to its hype. The study published in the June 1999 issue of the Journal of the American Medical Association compared 300 mg of androstenedione with a dummy pill in 20 men ages 19 to 29 during an eight-week weightlifting program. Researchers found no difference in strength between the two groups of men.
What About Hormone Replacement?
Since Andro converts into testosterone and estrogens, some doctors use it as a substitute for hormone replacement for women after menopause or for older men. Perhaps low doses used for brief periods of time may be helpful, but no long term research is available to compare the benefits versus the risks.
Mechanism of Action
Since Andro converts into testosterone, it does make sense that it should have sex-boosting properties similar to testosterone. Most studies show Andro raises blood levels of testosterone and estrogens. In addition, Andro very likely enters cells of various organs and tissues in the body and converts to testosterone and estrogens within the cells.
My Experience
I personally have not taken Andro since my skin is very sensitive to androgens, I break out in acne within a few days after taking DHEA or even pregnenolone. However, I have definitely noticed libido-boosting effects from DHEA and pregnenolone.
What My Patients Say
Both male and female patients frequently report to me that they notice a libido-boosting effect from this hormone. Others find that they can ejaculate easier. Occasionally someone will notice the effect within an hour, but more commonly the libido enhancement is noticed the next day or third day of use. Hence, if you expect to be sexually active over the weekend, you could take Andro Thursday and Friday.
On the other hand, and I don't know how to explain it, I have had reports from individuals who have noticed a decrease in libido while taking Andro daily for many weeks. A 32 year-old male patient says, "I tried Andro 100 mg a day for 3 weeks while weight training and noticed no positive effects, and if anything my libido appeared to go down."