Butagest, also known as buterol is a modification of megestrol acetate in which the C-3 ketone has been replaced by a C3β butanoyloxy moeity. It is chemically known as 3β-hydroxy-6-methyl-17α-hydroxypregna-4,6-dien-20-one 3β-butanoate 17α-acetate or 6-methyl-17α-hydroxy-δ⁶-progesterone 3β-butanoate 17α-acetate and is a steroidal progestin which was developed in Russia for potential clinical use as a progesterone supplement primarily for Hormone replacement therapy but it was never marketed for reasons which are still unclear.

Butagest is a synthetic progestin that mimics the physiological actions of natural progesterone. It is used in various therapeutic contexts, including hormone replacement therapy, fertility treatments, and menstrual irregularities.

Butagest acts as an agonist at progesterone receptors in various tissues. Its primary actions include:

By stabilizing the endometrium, it prevents abnormal uterine bleeding and aids in maintaining hormonal balance during assisted reproductive therapies.

The use of Butagest, which contains progesterone, is associated with several adverse effects. These vary depending on the dose, route of administration, and individual susceptibility.

These effects require immediate medical attention:

Butagest should be used cautiously in patients with a history of:

Regular monitoring is recommended for those with: