What was responsible for Tarzan's one year suspension? As reported by UDN.com, Clomiphene (Clomiphene citrate) is the answer.
Interesting excerpts from wiki on the substance:
-Rare adverse effects (<0.1%>alopecia-Clomifene is commonly used by male anabolic steroid users to bind the estrogen receptors in their bodies, thereby blocking the effects of estrogen, i.e., gynecomastia. It also restores the body's natural production of testosterone. It is commonly used as a "recovery drug" and taken toward the end of a steroid cycle.
In all fairness to Tarzan though, he did not test positive for anabolic steroid use. Also clomiphene citrate has been used to help restore fertility in men.
This is what Tarzan has been claiming is the root of why he tested positive for a banned substance. Tarzan has been married since 1999 and is still childless.