Formestane

Formestane belongs to a class of drugs known as aromatase inhibitors. It is used in the treatment of estrogen-receptor positive breast cancer in post-menopausal women. It is available as an intramuscular depot injection (Lentaron).

Formestane is often used to suppress estrogen production from anabolic steroids or prohormones.

Formestane has poor oral bioavailability and as such is no longer popular as many orally available aromatase inhibitors have been developed.

It is available as a supplement for bodybuilders in transdermal formulations.