Cymegesolate (developmental code name Progestin No. 1), also known as cypionyl megestrol acetate or as megestrol acetate 3β-cypionate, is a

progestin A progestogen, also referred to as a progestagen, gestagen, or gestogen, is a type of medication which produces effects similar to those of the natural product, natural female sex hormone progesterone in the body. A progestin is a ''synthetic co ...

medication which was never marketed.Chi-ming, L. (1983). New Long Acting Contraceptive Progestagen Studies on Synthesis of “Cymegesolate” Reproduction & Contraception, 4, 011.Hui-ling, Y. Y. C. C., & Jin-fen, S. (1982). Key Words: Long-acting Progestogen Contraceptive 3-Cyclopentyl Propionate of Megestrol Acetate (Progestin No. 1), Pharmacology, Rabbits; Pharmacological Study on a Long-Acting Progestogen Contraceptive 3-Cyclopentyl Propionate of Megestrol Acetate (Progestin No. 1) Reproduction & Contraception, 4.Xue-jing, W. J. Z. Y., & Mo-zhen, W. (1983). Clinical Study of a Long-Acting Progestogen Contraceptive 3-Cyclopentyl Propionate of Megestrol Acetate (Progestin No. 1) Reproduction & Contraception, 2, 009. It was developed in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

in the late 1970s and early to mid 1980s for use as a

hormonal contraceptive Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The origin ...

. The medication was formulated at a dose of 50–100 mg in combination with a "trace" dose of 0.25–0.5 mg quinestrol as a long-lasting, once-a-month

combined oral contraceptive pill The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. The pill contains two important hormones: progest ...

. This combination has been studied in 1,213 women across a total of 9,651

menstrual cycle The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that make pregnancy possible. The ovarian cycle controls the production and release of eggs a ...

s, with contraceptive effectiveness of over 99.13% and "very few side effects." At the high dose (100 mg / 0.5 mg), it showed an anovulation rate of only about 60%, and instead mediated its contraceptive effects via a marked anti-implantation effect.

Chemistry

Cymegesolate, also known as megestrol acetate 3β-cypionate, as well as 17α-acetoxy-6-dehydro-6-methylprogesterone 3β-cyclopentylpropionate or 17α-acetoxy-6-methylpregna-4,6-diene-3,20-dione 3β-cyclopentylpropionate, is a

synthetic Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to: Science * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic o ...

pregnane

steroid A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...

and a

derivative In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. F ...

progesterone Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the m ...

and

17α-hydroxyprogesterone 17α-Hydroxyprogesterone (17α-OHP), also known as 17-OH progesterone (17-OHP), or hydroxyprogesterone (OHP), is an endogenous progestogen steroid hormone related to progesterone. It is also a chemical intermediate in the biosynthesis of many ot ...

. It is the C3β

cypionate Cypionic acid, also known as cyclopentylpropionic acid, is an aliphatic carboxylic acid with the molecular formula C8H14O2. Its salts and esters are known as cypionates or cipionates. The primary use of cypionic acid is in pharmaceutical formula ...

(cyclopentylpropionate)

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...

of megestrol acetate. A closely related medication is acetomepregenol (mepregenol diacetate; also known as megestrol 3β,17α-diacetate), which, in contrast, has been marketed.

References

{{Progesterone receptor modulators Abandoned drugs Acetate esters Carboxylate esters Conjugated dienes Cyclopentanes Hormonal contraception Ketones Pregnanes Prodrugs Progestogens