Death, A. K., McGrath, K. C., Kazlauskas, R., & Handelsman, D. J. (2004). Tetrahydrogestrinone is a potent androgen and progestin. The Journal of Clinical Endocrinology and Metabolism 89, 2498-2500.

THG (Tetrahydrogestrinone) was shown to interact with human androgen receptors and progestin receptors transformed in a yeast-based in vitro bioassay. Gestrinone and Trenbolone were also evaluated for interactions.

THG was shown to be more reactive than either of its two derivative steroids, Gestrinone and Trenbolone. As well, it was more reactive than Nandrolone, indicating a high level of androgen potential, and more reactive than Progesterone, indicating a high level of progestin potential.

The investigators suggested: "Further studies are required to characterize the full spectrum of hormonal and toxicological properties of THG" (p. 2499). This is important because it means the demonstrated effects of the current study are insufficient to conclude about other properties or effects on humans. One would be in error to infer attributes of THG to human performance from the little that is known about the substance.

Implication. THG may have androgen and progestin properties but one cannot infer performance-enhancing properties to human activities.

Return to Table of Contents for this issue.