Levonorgestrel butanoate (LNG-B) (developmental code name HRP-002), or levonorgestrel 17β-butanoate, is a

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 ...

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 female sex hormone progesterone in the body. A progestin is a ''synthetic'' progestogen. Pro ...

of the

19-nortestosterone Nandrolone, also known as 19-nortestosterone, is an androgen and anabolic steroid (AAS) which is used in the form of esters such as nandrolone decanoate (brand name Deca-Durabolin) and nandrolone phenylpropionate (brand name Durabolin). Nandrolon ...

group which was developed by the

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...

(WHO) in collaboration with the Contraceptive Development Branch (CDB) of the

National Institute of Child Health and Human Development The ''Eunice Kennedy Shriver'' National Institute of Child Health and Human Development (NICHD) is one of the National Institutes of Health (NIH) in the United States Department of Health and Human Services. It supports and conducts research aime ...

as a long-acting injectable

contraceptive Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent unwanted pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth contr ...

. It is the C17β butanoate

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 ...

levonorgestrel Levonorgestrel is a hormonal medication which is used in a number of birth control methods. It is combined with an estrogen to make combination birth control pills. As an emergency birth control, sold under the brand name Plan B One-Step amon ...

, and acts as a

prodrug A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the dru ...

of levonorgestrel in the body. The drug is at or beyond the phase III stage of clinical development, but has not been marketed at this time. It was first described in the literature, by the WHO, in 1983, and has been under investigation for potential clinical use since then.Benagiano, G., & Merialdi, M. (2011). Carl Djerassi and the World Health Organisation special programme of research in human reproduction. Journal für Reproduktionsmedizin und Endokrinologie-Journal of Reproductive Medicine and Endocrinology, 8(1), 10-13. http://www.kup.at/kup/pdf/10163.pdf LNG-B has been under investigation as a long-lasting injectable contraceptive for women. A single

intramuscular injection Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles hav ...

of an aqueous suspension of 5 or 10 mg LNG-B has a duration of 3 months, whereas an injection of 50 mg has a duration of 6 months. The drug was also previously tested successfully as a

combined injectable contraceptive Combined injectable contraceptives (CICs) are a form of hormonal birth control for women. They consist of monthly injections of combined formulations containing an estrogen and a progestin to prevent pregnancy. CICs are different from progestoge ...

with estradiol hexahydrobenzoate, but this formulation was never marketed. LNG-B has been tested successfully in combination with

testosterone buciclate Testosterone buciclate (developmental code names 20 Aet-1, CDB-1781) is a synthetic, injected anabolic–androgenic steroid (AAS) which was never marketed. It was developed in collaboration by the Contraceptive Development Branch (CDB) of the N ...

as a long-lasting injectable contraceptive for men as well. LNG-B may have several advantages over

depot medroxyprogesterone acetate Medroxyprogesterone acetate (MPA), also known as depot medroxyprogesterone acetate (DMPA) in injectable form and sold under the brand name Depo-Provera among others, is a hormonal medication of the progestin type. It is used as a method of bir ...

, including the use of much lower comparative dosages, reduced progestogenic

side effect In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...

s like

hypogonadism Hypogonadism means diminished functional activity of the gonads—the testes or the ovaries—that may result in diminished production of sex hormones. Low androgen (e.g., testosterone) levels are referred to as hypoandrogenism and low estroge ...

and

amenorrhea Amenorrhea is the absence of a menstrual period in a woman of reproductive age. Physiological states of amenorrhoea are seen, most commonly, during pregnancy and lactation (breastfeeding). Outside the reproductive years, there is absence of menses ...

, and a more rapid return in

fertility Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Ferti ...

following discontinuation. The drug has a well-established

safety Safety is the state of being "safe", the condition of being protected from harm or other danger. Safety can also refer to the control of recognized hazards in order to achieve an acceptable level of risk. Meanings There are two slightly di ...

record owing to the use of levonorgestrel as an oral contraceptive since the 1960s.

References

{{Progesterone receptor modulators Abandoned drugs Androgens and anabolic steroids Butyrate esters Contraception for males Estranes Hormonal contraception Prodrugs Progestogen esters Progestogens World Health Organization

See also

References