Levonorgestrel cyclobutylcarboxylate

Levonorgestrel cyclobutylcarboxylate (or levonorgestrel 17β-cyclobutylcarboxylate; developmental code name HRP-001) is a progestin and a progestogen ester which was studied for potential use as an injectable hormonal contraceptive but was never marketed. It was developed by the World Health Organization's Special Programme on Human Reproduction in the 1980s. Analogues of levonorgestrel cyclobutylcarboxylate include levonorgestrel butanoate (HRP-002) and levonorgestrel cyclopropylcarboxylate (HRP-003).