Androstendione

Supplement companies have seized the opportunity to market pro-hormones like DHEA and androstenedione to consumers who hope for an anabolic explosion of testosterone. Unfortunately, most of these substances have little if any effect on circulating testosterone levels in healthy people. Even if pro-hormones were more effective at elevating testosterone levels than the research indicates, lack of testosterone is seldom the limiting factor in the muscle growth of the healthy young males who buy this stuff.

Androstenedione is a direct hormone precursor of testosterone. The theory behind supplementation is that if you put more of the pre-testosterone hormone in your system, your body will manufacture more testosterone. This is true only if you have sub-standard testosterone levels to begin with. Hormone formation and use is under extremely delicate control of multiple enzymes, eicosanoids, and other body chemicals. If all you had to do was take precursors of hormones to boost testosterone levels, you could just eat lots of cholesterol — that’s the raw material for all your steroid hormones!

The problem with supplementing with androstenedione, or any other pro-hormone, is that your body increases or decreases other hormones in the testosterone chain to balance things out. That’s where the health problems come in. Androstenedione by itself is highly androgenic¹, supplying all the undesirable side effects of elevated androgens – hair loss, prostate hypertrophy, acne, etc. Androstenedione can also be directly converted into estrogen, and this is apparently one of the safeguards our bodies initiate when androstenedione levels begin climbing². Elevated estrogen levels in men promote breast swelling and increased body fat storage. Estrogens seem to have a detrimental effect on the cardiovascular system in men and are positively correlated with many risk factors for atherosclerosis^3,4.

In a recent study on the effects of oral androstenedione supplementation on healthy young men, the results showed that testosterone concentrations were not affected by androstenedione administration, but estrogen concentrations were higher in the androstenedione group compared to their pre-supplement levels. There was no difference between the androstenedione group and the placebo group in knee extension strength, muscle fiber increase, lean body mass, or decrease in body fat levels. HDL cholesterol (the good kind), was lowered in the androstenedione group. The authors concluded that in normal men, androstenedione supplementation does not increase serum testosterone levels or enhance skeletal muscle, and may result in adverse health consequences⁵.

MAIN STEPS IN HUMAN SYNTHESIS
OF STEROID HORMONES

This diagram shows some of the checks and balances that keep oral pre-testosterone supplements from raising testosterone levels too high. Many andro-stack products try to sneak around our bodies regulatory mechanisms by including ingredients that try to overcome our natural limiting factors. Common additions are DHEA, chrysin, saw palmetto, Indole-3-carbinol, and Tribulus terrestris.

1. DHEA and androstenedione combinations are not smart if your sole purpose is to raise testosterone. 17b-HSD (17 beta-hydroxysteroid dehydrogenase) is necessary to convert DHEA to testosterone, and also to convert androstenedione to testosterone. Metabolic competition for this enzyme creates a bottleneck. Adding DHEA to the Andro stack is purely marketing strategy⁶.
2. Chrysin is worthless due to its very poor bioavailability. It’s also a known carcinogen⁷.
3. Saw palmetto inhibits the 5-alpha-reductase enzyme. This works well for its medical use of reducing prostatic hypertrophy, but when you’re talking about building muscle tissue, there are some problems. When you inhibit the conversion of testosterone to DHT (via inhibiting 5-alpha reductase), more testosterone is aromatized, which converts testosterone into estradiol (an estrogen).
4. Indole-3-carbinol is intended to bind to the estrogen receptors, which it does. But it is also an androgen disrupter which lowers testosterone levels in all the animal studies, so we would expect the same effect in humans⁷.

There is a recent study that shows that higher doses of androstenedione do in fact temporarily raise serum testosterone levels. It also showed that estrogen levels rose commensurately⁸, and with that come all the associated problems. The important thing to remember is that the overall androgen/estrogen ratio and testosterone/DHT ratio will not change significantly with oral androstenedione⁶.

Research Cited:

1. Anabolic Steroids in Sport and Exercise, Human Kinetics, 1993.
2. J Amer Med Assoc, 1999;281:2020-2028.
3. The Coronary Drug Project Research Group. The Coronary Drug Project: findings leading to discontinuation of the 2.5-mg/day estrogen group. J Amer Med Assoc.1973;226:652-657.
4. Mendoza SG, Zerpa A, Carrasco H, et al. Estradiol, testosterone, apolipoproteins, lipoprotein cholesterol, and lipolytic enzymes in men with premature myocardial infarction and angiographically assessed coronary occlusion. Artery.1983;12:1-23.
5. King, et al. Effect of oral androstenedione on serum testosterone and adaptations to resistance training in young men. J Amer Med Assoc, 1999;281:2020-2028.
6. Greenwalt, David, androstendione specialist, in an interview in Muscle and Fitness, July, 1998.
7. Thomas Inclendon RD, Director of Sports Nutrition, Human Performance Specialists, Inc. via e-mail, 2000.
8. J Amer Med Assoc, Oral Androstenedione Administration and Serum Testosterone Concentrations in Young Men 2000;283:779-782.

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