levonorgestrel butanoate

Levonorgestrel butanoate is a long-acting injectable progestin developed as a contraceptive for women. It is the C17β butanoate ester of levonorgestrel and acts as a prodrug that releases active levonorgestrel after hydrolysis in the body[2][3]. As a member of the 19-nortestosterone group of steroidal progestins, it exerts its effect primarily by inhibiting ovulation and thickening cervical mucus to prevent sperm penetration. Levonorgestrel butanoate was developed by the World Health Organization (WHO) in collaboration with the Contraceptive Development Branch (CDB) of the National Institute of Child Health and Human Development (NICHD)[2][3]. It is administered via intramuscular or subcutaneous injection and has been studied for use as an estrogen-free, long-lasting reversible contraceptive option[7][3]. The drug remains investigational; it has reached at least phase I/III clinical development stages but has not been marketed[2][7].

Other names

levonorgestrel 17β-butanoate17α-ethynyl-18-methyl-19-nortestosterone 17β-butanoate17α-ethynyl-18-methylestr-4-en-17β-ol-3-one 17β-butanoatelevonorgestrel butyrate