Flugestone acetate

Flugestone acetate (FGA), sold under the brand name Cronolone among others, is a progestin medication which is used in veterinary medicine.



FGA is used as an intravaginal sponge preparation to synchronize estrus in ewes and goats.


FGA, also known as 17α-acetoxy-9α-fluoro-11β-hydroxyprogesterone or as 17α-acetoxy-9α-fluoro-11β-hydroxypregn-4-ene-3,20-dione, is a synthetic pregnane steroid and a derivative of progesterone and 17α-hydroxyprogesterone. It is the C17α acetate ester of flugestone.


FGA was developed and marketed by G.D. Searle & Company in the 1960s.

Society and culture

Generic names

Flugestone acetate is the generic name of the drug and its and , while flurogestone acetate is its . Flugestone is the and of the unesterified free alcohol form. FGA is also known by its developmental code names NSC-65411 and SC-9880.

Brand names

FGA is or has been marketed under the brand names Chronogest, Chrono-Gest, Crono-Gest, Cronolone, Gyncro-Mate, Ova-Gest, Ovakron, Synchro-Mate, Syncro Part, and Syncropart.


FGA is marketed for veterinary use in Australia, France, Ireland, Israel, Italy, the Netherlands, South Africa, and the United Kingdom.