A Discussion on Prohormones

by Panos Prokos, MS, CSCS

Prohormones are naturally occurring chemical compounds similar to actual hormones. However, they do not exert their action directly but only after they have been converted to the final target hormone. This process is achieved through the help of enzymes found naturally within the body. Prohormones require these enzymes in order to complete the conversion process. However, these enzymes can only convert a limited amount of prohormone within a given period. The conversion process, which takes place in the body, is what differentiates prohormones from steroids, and allows the former to remain legal. The downside of this conversion process lies in the limited amount of enzymes which predetermine how much hormone will actually become available. In other words, taking too much prohormone does NOT equal a respective increase in the amount of final hormone. This is one of those cases where more is not always better.

The actual sequence through which a target hormone is produced is the following:

Cholesterol > Pregnenolone > Dehydroepiandrosterone (DHEA) > 4-Androstenedione > 4-Androstenediole > Testosterone

The adrenal glands produce several different hormones. One of them is DHEA. This is an androgen, which is able to convert to sequential products through the enzymatic process. Two of the enzymatically converted products of DHEA are 4-androstenedione and 4 androstenediol which in turn are converted into testosterone via the 17-BHSD and 3-BHSD enzymes respectively. It should be noted though that through this enzymatic conversion, other byproducts are also formed including the dreaded estrogens. It has been suggested, however that high intensity training promotes a pro 17-BHSD and 3-BHSD environment, which in turn results in a favorable conversion rate of these two DHEA conversion products to testosterone.

One other thing to notice is the importance of cholesterol in the hormonal synthesis process. In other words, a limitation in the available cholesterol will result in a decreased amount of hormone produced. Hence the importance of consuming adequate fat during a muscle building stage. Now this does not give you an excuse to indulge in junk food. It just means that complete elimination of fat from your diet may negatively affect hormonal production so keep this in mind, if you are training for mass.

Now, lets go ahead and take a look at some of the most common prohormones available in the market.

1-Testosterone

1-test is actually a target hormone and not a precursor despite it is commonly known as such. Strong anabolic properties and no aromatization to estrogens. It exerts its effects directly and not after an enzymatic conversion. It is therefore responsible for unwanted side effects such as hair loss, benign prostate enlargement (BHP), acne, etc.

1AD (1-androstene-3beta, 17beta-diol)

1AD is the precursor to 1-Testosterone described above and therefore possesses all the pros and cons of this hormone. However, it actually increases the risk of side effects as a result of the conversion byproducts. In addition to this it exhibits a level of efficiency lower than that of 1-Test since only part of it will actually be converted (depending on enzyme efficiency).

4-AD (4-androstenediol)

4-AD is a direct precursor to Testosterone and therefore it provides the same benefits Testosterone does. However, as with 1-AD, it has to undergo a conversion process, which in turn may increase conversion metabolites and decrease the actual amount of converted testosterone. Therefore side effects are again possible.

Nordiol (19-nor-4-androstenediol)

Nordiol does not convert to testosterone but to nortestosterone and therefore produces less androgenic effects (and side effects). Although it does not convert to estrogen through the typical pathways, it still possesses the ability to do give unwanted estrogen like effects through the progesterone pathway.

1,4-Andro (1,4-androstadiene-3, 17-Dione)

This prohormone is relatively free of side effects including water retention, yet it possesses relatively adequate anabolic properties. However, it also converts into estrogen and therefore increases the chances for estrogen related side effects such as gynecomastia, mild water retention, but most of all HPTA inhibition, (see my other article on this).

The above is a simplified model describing the basic characteristics and effects of prohormones. As a closing statement I would like to make clear that use of prohormones may result in dangerous and unwanted side effects similar to the ones obtained from steroids. In fact, if one has to choose between prohormones and steroids, the risk to benefit ratio is clearly in favor of steroids. Neither the results nor the risk ratio afforded by prohormones justify their use as a performance aid.