Androstenedione (or “andro”) is a naturally occurring human hormone which is produced in the body as a precursor to other hormones such as testosterone and estradiol. Andro does not appear to be anabolic (does not promote muscle growth) but it can possibly enhance sports performance by temporarily raising testosterone levels in the body (meaning it falls into the category of compounds known as “androgenic”).

The structure of androstenedione.

Andro was legal in North America up until the end of the 1990’s and was used by popular sports figures such as Mark McGwire who, in 1998, broke the record for most home runs hit in a season. So perhaps it does help! It’s not recommended as  a sport supplement, however; as with other androgenic compounds, it carries the risk of side effects ranging from liver problems to cancer.