<p><strong>GYNECOMASTIA (Bitch Tits)</strong></p>

- Thomas O’Connor

Anabolic-androgenic steroid (AAS) use is associated with a host of side effects; some can be serious and cause medical disease, while others are more of a nuisance and can lead to poor quality of life and cosmetic issues like gynecomastia. Of all the known side effects of AAS, gynecomastia has to be one of the most infamous among users. On the Internet steroid boards, there are endless numbers of blog posts discussing it; a review of what we actually know about AAS-related gynecomastia should be useful.

Since the early days of AAS use, men have been suffering with anabolic steroid-induced gynecomastia (ASIG)— ironically known as “bitch tits” among men who take these drugs to be big, strong, and to enhance their masculine physiques. Soon after starting these agents, many men develop tender, puffy nipples that resemble a woman’s breast. This issue is a common reason why men come to see me.

Let’s review the basic physiology of how AAS lead to increased or supraphysiologic estrogen levels and resultant gynecomastia. It should be noted that not all AAS that cause gynecomastia do so by direct conversion to estrogen. Some can directly and or indirectly cause gynecomastia via other specific mechanisms of action (MOA). For example, Anadrol and its relation to inherent estrogenic activity and the AAS trenbolone and nandrolone, are associated with developing gynecomastia via direct stimulation of breast progesterone receptors in addition to causing elevated levels of systemic prolactin.

We know that the classic “estrogenic&rdquo