Androstenedione, Grand Daddy of All Prohormones: Carcinogenic Poison or Non-Toxic Muscle Builder?

I suspect you have already read statements like "prohormones will kill your liver", "prohormones will give you gyno" and/or "prohormones will induce prostate cancer", haven't you? Well, Androstenedione is not methylated, so bro-science would tell you that your liver won't take a beating. Yet, all gynecomastia issues aside, what if its not the methyl-group but the prohormone itself that is liver toxic or carcinogenic? A recent study published in the journal of Food and Chemical Toxicology on May 30 2011 (Blystone. 2011) sheds some light onto potential side effects of the "grand daddy of all prohormones".

Chard R. Blystone and his colleagues administered  "subchronic" doses of androstenedione @ 10, 20, or 50 mg/kg body weight to male and @ 2, 10, or 50 female mice. And they did that for two years.

Figure 1: Cancer risk of male F344/N rats after 2 years of chronic exposure to androstenedione at 10, 20, or 50mg/kg body weight relative to 0mg control (data adapted from Blystone. 2011)

To put that into perspective, an average androstenedione cycle lasts anywhere from 4-8 weeks and dosages range from 100-600mg/day, considering the fact that the average laboratory rat weighs about 300g and the human equivalent dose of the highest, 50mg/kg dose, is 8.1mg/kg (this would equal a 650mg daily dose for a 80kg human being), the rats receiving 50mg/kg androstenedione per day for two years were exposed to the equivalent of 473513.51mg or roughly 440g of androstenedione. In their abstract the scientists summarize their observations as follows:

Increased incidences of lung alveolar/bronchiolar adenoma and carcinoma occurred in the 20 mg/kg male rats and increases in mononuclear cell leukemia occurred in the 20 and 50 mg/kg female rats, [...]. In male and female mice, androstenedione was carcinogenic based upon a significant increase in hepatocellular tumors [cancerous growth in the liver]. A marginal increase in pancreatic islet cell adenomas in male (50 mg/kg) and female (2, 10, 50 mg/kg) mice was considered to be related to androstenedione administration.

While this does sound pretty dangerous looking beyond the abstract and at the actual data, part of which I plotted for you in figure 1, does yet speak a very different language. Although the scientists also mention that to their own surprise androstenedione decreased "incidences of male rat Leydig cell adenomas and female rat mammary gland fibroadenomas", they did not mention that it did so (if not always in a statistically significant manner) in mononuclear cell leukemia and interstitial cell adenoma, as well (cf. figure 1). While the situation is somewhat different in female rats (who would have suspected that supra-physiological doses of testosterone //this is what andro will initially convert to// would be bad for female mice ;-), this is another incidence, where someone who relied solely on the abstract, would be fooled into overestimating the negative and to underestimate unexpected positive effects of a drug that has been vilified like very few compounds before it.

In view of these results, some bros may now argue that taking androstenedione could actually be beneficial for your health, "protecting" you from several types of cancer! Well, before you jump on that bandwagon, remember that these are probably the same bros of whom you will read on various boards, that they use androstenedione or similar "mild" prohormones to fill the gaps between cycles of much harder steroids... As a reader of the SuppVersity, you get the facts, the interpretations and, even more importantly, the real world choices you make are up to you.