Molecule Monday: Androsta-3,5-diene-7,17-dione (Arimistane)



Today I’m going to talk about an aromatase inhibitor that I saw in quite a few products. Androsta-3,5-diene-7,17-dione, also known as Arimistane, is a pretty strong OTC aromatase inhibitor (aromatase is the enzyme that converts androgens into estrogens). This compound is a metabolite of DHEA (dehydroepiandrosterone), which is the most common endogenous steroid hormone in the body, and 7-keto-DHEA. It’s been shown to have a very high binding affinity to aromatase, with a Ki value of around 0.2 uM, (the lower the better) roughly half of the formally sold aromatase inhibitor 6-OXO. It acts as a suicide inhibitor, meaning it irreversibly binds the aromatase and renders it inactive.  This can be very beneficial to people either taking androgens that can convert to estrogen, or taking it when coming off androgens, to control estrogen rebound levels. Another interesting property of this compound is that it may also lower cortisol. The keto group on carbon 7 may act as a hydride acceptor (H-) from the the enzyme 11-betahydroxysteroid dehydrogenase(11-bHSD) which is responsible for turning inactive cortisone into active cortisol. A little bit of cortisol is beneficial, while chronic elevated levels can break down muscle. Based on it’s structure and being a 7-keto-DHEA derivative, it may also have some of the same properties like increasing LH and decreasing sex hormone-binding globulin, although more research is needed. Overall, for an OTC compound, it may have some benefit for athletes.  This compound can be found in Eradicate and PCT V by @blackstonelabs #musclechem