Nonessential Micronutrient



Touted as the “natural steroid alternative,” andro has become as well known as Prozac — thanks to the media. Having reached its height of popularity during Mark McGuire’s homerun-record-setting season, it has since been banned by nearly every major sport, making androstenedione — a direct precursor to testosterone — nearly as controversial as the steroids it was intended to replace.

Other names for Androstenedione

andro, androstenediol, 19-norandrostenedione, 19-norandrostenediol, 4-androstenediol, 5-androstenediol

Where to find Androstenedione

Androstenedione, naturally made by our bodies, is produced in the adrenal glands and gonads.

Interestingly enough, it can also be found in nature within the pollen of Scotch pine trees.


Why athletes use Androstenedione

Androstenedione is primarily used by male athletes and aging men who hope to increase testosterone levels. It is surrounded by controversy because while it does appear to increase testosterone for short periods of time, there isn’t significant evidence that it in turn increases muscle mass or strength. Androstenedione does, nonetheless, appear to significantly increase libido and is more recently becoming popular for that reason.
Ways that Androstenedione can enhance Muscle Gain & Recovery:

  • Increase strength and muscle mass by raising natural testosterone levels

Ways that Androstenedione can enhance Longevity:

  • Increase libido (sex drive) by reversing the natural age-related decline of testosterone


Signs of Androstenedione deficiency

No deficiency conditions exist; however, levels of natural testosterone in the body may decline with age.

Potential uses for Androstenedione

Research indicates that Androstenedione may be useful in the treatment of:

  • Low libido (sex drive)
  • Low testosterone levels


More about Androstenedione

As you’re probably well aware, testosterone is the hormone produced in our bodies that is responsible for our more masculine characteristics, such as deepening of the voice and facial hair. Because testosterone plays such a significant role in the maturing of our bodies as well as its ability to help build muscle, it’s long been coveted by athletes seeking to enhance their physiques.

After first being used by East Germans to enhance the performance of their Olympic athletes and later studied extensively throughout the 1980’s, a supplement touted as being able to significantly boost testosterone levels and naturally increase muscle gains came about. Its name? Androstenedione.

What is it, and how does it work?

Androstenedione is an androgenic hormone produced naturally in men and women that’s converted by the liver into testosterone. It’s produced in the adrenal glands and gonads by DHEA (dehydroepiandrosterone) or 17-a-hydroxyprogesterone for those technical gurus. In essence, androstenedione is a mere single step away (that is, one metabolic reaction in the body) from testosterone.

So from this, the assumption has been made that when androstenedione is ingested, it readily converts to testosterone, and when combined with physical exercise, the direct result is muscular growth. But, it’s not that simple. You see, androstenedione’s effects on human muscle growth are still “up in the air” in the scientific community since no studies to date have revealed direct positive effects. Although there does appear to be a definite surge of testosterone in the blood when androstenedione is supplemented before a workout, which may lead to more “aggressive” weight-training sessions, potentially resulting in increased muscle growth.

Buyer beware

Although there is good evidence that andro can stimulate sex drive while you’re using it, numerous people have commented on the fact that libido is significantly, and perhaps even completely, reduced once supplementation has been stopped. You see, when the testes feel there is sufficient testosterone in the system, they shut down. So, unfortunately, people may be left with no libido, among other complications, after ceasing supplementation. A number of companies are trying to overcome this particular side effect by adding potential anti-estrogens, namely Tribulus terrestris, to their products to help kick start the natural production of testosterone when a “cycle” of andro is completed.

Other concerns include acne caused by the imbalance of hormones. Sadly, this isn’t ordinary, mild acne. Many people face large, unsightly boils. Hair loss can also be quite significant in people who are already prone to male-pattern baldness. More seriously, overuse could possibly lead to gynecomastia (the unsightly swelling of breast tissue in men). There is also concern that andro may lead to prostate enlargement and potentially increase the risk of cancer in this area. While these side effects don’t occur in everyone in every case, there is a scary reality that they can occur.

Highly controversial

Androstenedione remains a highly controversial supplement in the athletic and scientific communities alike. While its use has skyrocketed in the quest for increased muscle mass and performance, clearly more research is needed to explore its positive attributes and to learn more about its possible negative side effects before any recommendations can be made.

Acknowledgement as well as understanding the effects of the hormone testosterone may or may not deter you from using this highly debatable supplement. And since it is not yet documented if androstenedione produces similar results regarding increased muscle mass, it might be worth sitting this one out. Nonetheless, andro does have one effect that seems to be agreed upon — it increases libido. While it’s yet to have documented abilities to help build bigger, stronger muscles, it does appear to stimulate sex drive.

In conclusion

There is still a real need for long-term human research on all forms of this prohormone (androstenedione, 19-norandrostendione/diol, 4-androstenediol, 5-androstenediol, and androstenediols). The limited data that does exist offers evidence that the results for athletes are often negative. Still, anecdotal evidence suggests that some people benefit from andros, while others face a whole host of side effects.

Alternate, Similar Forms of Andro, Using Andro as a Basis:

Androstenedione Although androstenedione is the most well known, research indicates it fails to increase testosterone over the long term and that it can increase estrogen levels. It appears to be more beneficial in the bedroom than the gym and is recommended by some experts for short-term increases in sex drive.

Androstenediol Androstenedione and androstenediol are both direct precursors to testosterone. However, androstenediol uses a different enzyme to convert and may have a higher conversion rate.

19-Norandrostendione/diol The name implies what this supplement is for those folks who are into chemistry. For the rest of us, it simply means the 19th carbon atom was removed from androstenedione. Well, maybe that’s for the tech folks as well. Anyway, this small change in the chemical structure is theorized to make this product potentially more effective as an anabolic, while, more importantly, less androgenic. Still, experts are concerned that this one may have an even greater risk of shutting down the body’s natural production of testosterone than any of the other andro-like supplements and could result, for those who try it, in testing positively for steroids in a drug test.

4-Androstenediol The number four again indicates the chemical difference for this form of andro. (The 4 indicates the position of the double bond in the steroid family. This form is actually a precursor to androstenedione.) This product is believed to be superior in terms of conversion to testosterone, at least in test-tube studies. But, unfortunately, there’s no solid research that’s been performed with humans. New delivery systems are bringing this andro product to the forefront, but only time will tell if the research supports the manufacturers positive claims.

5-Androstenediol Like 4-androstenediol, there are great claims about this andro product, but there seems to be even less scientific data to support the claims regarding its benefits. While believed to potentially have less androgenic side effects, it still may raise estrogen levels. Again, the 5 indicates the position of the chemical bond in the steroid molecule. This form is a precursor to DHEA.



The ideal intake of androstenedione has not yet been determined, but in research, oral doses given to men at levels of 50 mg and 100 mg per day were shown to raise testosterone levels from 140% to 183% and 211% to 237%, respectively.


Androstenedione is typically taken in the morning before breakfast and again in the evening before dinner.

Strength trainers take note

Because testosterone levels peak in about 60 minutes, it has been theorized by some experts that an oral dose taken 60 minutes before a weight-training session may add a “strength boost” during a workout by increasing the immediate production of testosterone.

Consumer beware

Because andro is technically an androgen hormone, it may have somewhat of a “drug-like” effect within the body and reduce the body’s potential to naturally produce testosterone. Because of this, most experts recommend “cycling,” or going on and off androstenedione, for periods of no longer than three to four weeks on, followed by three to four weeks off.

Synergists of Androstenedione

Androstenedione is often used with DHEA and Tribulus terrestris to enhance the benefits of each.

Lysophosphatidylcholine may increase absorption of androstenedione.

Zinc, a mineral necessary for the natural production of testosterone, may boost the effects of androstenedione.

Chrysin and indole 3 carbinol are often used in formulas with androstenedione to help inhibit the conversion into or production of the potentially damaging hormone estrogen.

Safety of Androstenedione

This supplement is not recommended for women, as elevated testosterone levels may cause unwanted masculine characteristics, such as deepened voice, facial hair, and enlarged genitals.

Increased testosterone, which is the desired result of supplements such as androstenedione, can also lead to enlargement of the breasts, prostate, and other glandular tissues, increase the risk of glandular cancers, water retention, impotence, acne, oily skin, and increase sex drive.

Toxicity of Androstenedione

No known toxicity.

Bans and restrictions

Androstenedione has been banned by the National Football League, the International Olympic Committee, and the National Collegiate Athletic Association.


  • Earnest, C., et al., “In Vivo 4-Androstene-3,17-Dione and 4-Androstene-3Beta,17Beta-Diol Supplementation in Young Men,” Eur J Appl Physiol 81.3 (2000) : 229-32.
  • King, D.S., et al., “Effect of Oral Androstenedione on Serum Testosterone and Adaptations to Resistance Training in Young Men: A Randomized Controlled Trial (see comments),” JAMA 281.21 (1999) : 2020-8.
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