Understanding Prohormones - Safety, Precursors and the Effects

Prohormone Effects and Safety

Never put your health above temporary muscle gains

fitFLEX Articles - Learn, Share and Discover


What's the difference, if any, between prohormones, prosteroids and proanabolics?

When discussing bodybuilding supplements, the terms prohormone, prosteroid and proanabolic are interchangeable. All three terms refer to the same type of product.

A prohormone is a precursor or building block that gets converted to testosterone inside the body. Because testosterone is a steroid hormone with anabolic muscle building properties, a prohormone is a prosteroid, which is (hopefully) proanabolic.

Most prohormones are inactive and have only weak anabolic activity. Hence, any potential bodybuilding effect is entirely dependent on the prohormone's conversion to the active, anabolic hormone testosterone.

In theory, these supplements provide a natural method of increasing your body's testosterone level. However, the chemical conversion is the limiting step when it comes to prohormone effectiveness. Some scientific studies suggest only 10 to 15 percent of the prohormone dose is converted to testosterone. In terms of potency, this amount is only a small fraction of the dose.

The most common (human) steroid pre-cursors used by the supplement industry are androstenedione, norandrostenedione and dehydroepiandrosterone (DHEA). These natural products are legally available without prescription at health-food stores and are not subject to the same drug laws as pharmaceutical anabolic steroids. In essence, pro-hormones are legal, less potent, somewhat safer alternatives to anabolic steroids.


Do prohormones work? What's the current scientific opinion?

In theory, supplementing your diet with legal over-the-counter steroid prohormones raises your body's testosterone, which in turn boosts your anabolic muscle building potential. To realize whether steroid precursors work in practical terms, two questions must be addressed.

First, do prohormones elevate testosterone? Current scientific research indicates that the recommended 300 mg dose of pro-hormones, like androstenedione, can increase blood levels of testosterone levels. However, the effect is variable. At best, testosterone levels are raised toward the natural, peak physiologic concentration in young adult men.

Second, does this slight increase in testosterone translate into a bodybuilding advantage by increasing muscle size and strength? I other words, we know that prohormones boost your testosterone level, but does th. increase make you bigger and stronger? S far, clinical studies have failed to demonstrate any significant gains in muscle size and strength from steroid prohormones.

Despite this disappointing result, we must realize that proving bodybuilding benefits in scientific terms is not easy. After all, it took medical researchers almost half a century to finally acknowledge the muscle building powers of anabolic steroids and I suspect more research needs to been done before we draw our final conclusions. Suffice to say at this time, the testosterone boost provided by prohormones could give you an anabolic edge when combined with an appropriate bodybuilding exercise regimen and diet.


I am a natural bodybuilder and I've made some significant gains during my two years of training. Lately, I have hit a plateau and my gains have slowed. I was advised to try prohormones to give my physique a jump-start. Are prohormones safe? I want a great body, but I don't want to jeopardize my health. Any information you could provide on this topic would be helpful. Thank you.

Thanks for raising the issue of hormone safety. Even though these steroid precursors are legal over-the-counter supplements, prohormones are not free of potential problems. Here's the current scientific scoop on prohormones.

Research studies investigating the effects of androstenedione given to healthy adult men in daily doses of 300 mg for up to 12 weeks have found the product to be relatively safe. However, some researchers have raised several concerns about whether prohormones may produce similar side effects to anabolic steroids.

Androstenedione is a steroid precursor and its biochemical inter conversions are complex. Not only does androstenedione convert to the male hormone testosterone, it also aromatizes into the female hormone estrogen.

In men, raised estrogen levels can cause gynecomastia - the development of female breast tissue. Androstenedione has also been shown to reduce the blood concentration of good HDL cholesterol, which may increase the risk of cardiovascular disease. Some male users have experienced acne as a side effect of prohormone use. Women have a risk of developing masculine features (hirsutism) and children may suffer from stunted growth.

Some good news is available. Prohormones, like androstenedione, exhibit less severe side effects than anabolic steroids and lo not appear to affect liver enzymes or suppress the pituitary hormones (FSH and LH).

The bottom line - scientific research suggests the recommended daily dose of prohormones, like androstenedione, taken for short periods of up to three months is relatively safe in healthy adult men.


What chemicals do the so-called barely legal anabolic supplements contain? Are they anabolic steroids?

Several so-called legal or natural anabolic products have emerged in recent years. Such supplements are marketed freely in the United States due to the exemption of natural products from the US Food and Drug Administration regulation. Most of these chemicals are steroid precursors, aka anabolic prohormones. Other poorly defined products contain secret ingredients derived from plant, insect or animal materials.

Unfortunately, being exempt from FDA regulation gives some disreputable manufacturers the ability to deceive consumers. A recent research study took the liberty of analyzing the contents of nine different brands of prohormones. What they discovered is pretty shocking. Six out of the nine brands tested were mislabeled and did not contain the ingredients or the doses listed on the label. Only three brands contained the dosage listed on the side of the bottle. One brand contained only trace amounts and another contained no prohormone at all!

What's even more confusing is that some of these legal anabolic steroid precursors have trade names that bare a striking similarity to pharmaceutical-grade prescription-only anabolic steroids. If these products did contain pharmaceutical agents, such as testosterone, stanozolol, methandrostenolone, boldenone, drostanolone, they would be classed as Schedule III Controlled Substances and would be illegal without a physician s prescription.

When you read the small print most of these products contain legal over-the-counter steroid precursors. Whatever the funky name the manufacturers decide to call their products the active ingredient is usually a prohormone similar to androstenedione, norandrostenedione and dehydroepiandrosterone (DHEA). That's fine because we know from clinical studies that these generic steroid precursors can elevate testosterone levels, giving your body an anabolic advantage.

Although these legal prohormones are not as potent as illegal pharmaceutical anabolics, they still carry a small risk of side effects, such as acne and gynecomastia, especially in larger doses. Whether these new products meet certain theoretical claims like higher anabolic ratios, non-aromatization and improved receptor binding has not been clinically proven.

Related Articles