A prohormone is a substance that is a precursor to a hormone, usually having minimal hormonal effect by itself.

Prohormones of anabolic steroids
In the last two decades, prohormones have also been used by bodybuilders, athletes, and nonmedical users of anabolic steroids and other hormones to refer to substances that are expected to convert to active hormones in the body. The intent is to provide the benefits of taking an anabolic steroid without the legal risks, and to achieve the hoped-for benefits or advantages without use of anabolic steroids themselves. Many of these compounds are legal to manufacture, sell, possess and ingest eliminating the legal problems associated with real steroids.

A typical prohormone is intended to be a precursor of an anabolic steroid like testosterone, which is taken in order to boost the body’s available hormone supply. These precursors are intended to be converted to full, active hormones via an enzymatic process that occurs during metabolism, typically resulting in the addition of whichever atoms happen to be missing from the chemical structure of the compound.

Prohormones are used mainly by athletes looking to increase size, strength, endurance, reduce recovery time or add lean body mass. They are most often used for increasing muscle mass or reducing body fat levels. Life extension groups are also increasingly using prohormones as a means of hormone replacement therapy, as an alternative to prescription drug use.

The use of prohormones has become popular among bodybuilders, since the effects can be similar (though normally much less drastic) to those achieved through the use of synthetic anabolic steroids, including gains in muscular strength and hypertrophy. There are currently many companies manufacturing prohormone products for this purpose.

Prohormones have the same side effects as anabolic steroids, and are dependent upon the user as to which side effects one might experience. Some side effects are acne, hair loss, breast tissue enlargement, and prostate swelling.

The potential for these side effects does exist, but it can be reduced if one uses proper precautionary measures such as post cycle therapy (PCT). Generally, if a person is genetically predisposed to a side effect it will occur (i.e.: if someone has a history of male pattern baldness in the family, it could be assumed that this could be a side effect experienced if prohormones are used)

On October 22, 2004, President Bush signed into law the Anabolic Steroid Control Act of 2004 (118 Stat. 1661). The bill was written to become effective in 90 days, which was January 20, 2005. This legislation places both anabolic steroids and some prohormones on a list of controlled substances (a new type of "regulatory control") This bans the selling or possessing of only the following prohormones.

The Pros and Cons of Pro-Hormones
Pro-hormones are easily found in every pharmacy, whole foods and supplement store. They used as a performance enhancing drug that people take as a professional aid. Pro-hormones are a naturally occurring chemical compound that is quite similar to actual hormones. The difference lies in the fact that they don't actually exert their actions immediately upon ingestion; it is only after being converted to the final target hormone that it starts acting on the body. The pro-hormones are converted to the final target hormone with the help of enzymes that are naturally found in the human body. It is only with the help and presence of these enzymes that its conversion process is completed. However, there is a drawback that the enzymes can convert only a small amount of pro-hormones in a given period of time. It is basically this conversion of pro-hormones with enzymes that differentiates a pro-hormone from a steroid and what permits pro-hormones to remain as a legal drug. The only drawback over a pro-hormone and a steroid is that there is no point in taking too much of the pro-hormone as this does not promise a respective increase in the final amount of hormones.

It should be noted that the enzymatic processes of pro-hormones gives numerous byproducts; and one of them is the dreaded hormone, estrogen. It is only with a high intensity workout and training that this hormone will get converted to testosterone. Another point to remember about pro-hormones is that there is a necessity of the presence of cholesterol in the body for the hormonal synthesis process of pro-hormones. This means that a reduction in the availability of cholesterol in the body only leads to a reduction in the amount of hormones produced. So it is important to consume fat during the muscle building stage of the body. However this does not imply that it is necessary to consume junk food; only that eliminating fat from the body will only lead to a negative effect on hormonal production.

There are many pro-hormones available on the market today; each having its own pros and cons. I-Testosterone is a target hormone having strong anabolic properties where there is no aromatization to estrogens. Instead, it exerts its effects immediately, and not with an enzymatic conversion; it is responsible for some side effects like hair loss, benign prostate enlargement and acne.

IAD (I-androstene-3beta, 17beta-diol) is the precursor to I-Testosterone and has similar pros and cons. However, as there are conversion byproducts here, there is an increase in the risk of side effects. Moreover, it offers a lower efficiency than I-Testosterone as only a part of it is converted in the conversion process.

4-AD (4-androstenediol) is another precursor to testosterone and offers the same benefits. However, as in the case of IAD, there is a conversion process here which leads to an increase in the conversion of metabolites. In addition to this, there is a decrease in the amount of converted testosterone wherein there may be side effects.

Nordiol (19-nor-4-androstenediol) is another pro-hormone that doesn't convert into testosterone. Instead it converts to nortestosterone to produce less androgenic effects and side effects. Thought there is no conversion to estrogen with typical pathways, you find that it produces unwanted estrogen through progesterone pathway.

1, 4-Andro (1, 4-androstadiene-3, 17-Dione) is a pro-hormone that has relatively fewer side effects. One of its side effects is water retention. However, it is a pro-hormone that has sufficient anabolic properties and also converts to estrogen in its conversion process. There is a possibility of an increase in estrogen related side effects like water retention, gynecomastia and most HPTA inhibitions.

Basically, the use of pro-hormones may result in dangerous and unwanted side effects that are similar to those that steroids produce. In fact, comparatively, when choosing between steroids and pro-hormones, the ratio of risk to benefit is in favor of steroids as both the results and risk ratio of pro-hormones offer no justification as a performance aid. I SUGGEST TO STAY AWAY FROM PRO-HORMONES AND STEROIDS THE RISKS AND NEGATIVES FAR OUTWEIGH ANY POSITIVES YOU MAY SEE!!!