Norgestrel, sold under the brand name Ovral among others, 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 female sex hormone progesterone in the body. A progestin is a ''synthetic'' progestogen. Pro ...

medication which is used in birth control pills and in menopausal hormone therapy. It is available both in combination with an

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...

and alone. It is taken by mouth. Side effects of norgestrel include menstrual irregularities,

headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of th ...

, breast tenderness, mood changes,

acne Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...

, increased hair growth, and others. Norgestrel is a progestin, or 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 ...

progestogen Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the bod ...

, and hence is an

agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ag ...

of the progesterone receptor, the biological target of progestogens like

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 majo ...

. It has weak androgenic activity and no other important hormonal activity. Norgestrel was patented in 1961 and came into medical use, specifically in birth control pills, in 1966. It was subsequently introduced for use in menopausal hormone therapy as well. Norgestrel is sometimes referred to as a "second-generation" progestin. It is marketed widely throughout the world. Norgestrel is available as a

generic medication A generic drug is a pharmaceutical drug that contains the same chemical substance as a drug that was originally protected by chemical patents. Generic drugs are allowed for sale after the patents on the original drugs expire. Because the active ...

. In 2020, the version with ethinylestradiol was the 316th most commonly prescribed medication in the United States, with more than 900thousand prescriptions.

Medical uses

Norgestrel is used in combination with ethinylestradiol or quinestrol in

combined birth control 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: progesti ...

s, alone in progestogen-only birth control pills, and in combination with estradiol or conjugated estrogens in menopausal hormone therapy. It has also been used as an

emergency contraceptive Emergency contraception (EC) is a birth control measure, used after sexual intercourse to prevent pregnancy. There are different forms of EC. Emergency contraceptive pills (ECPs), sometimes simply referred to as emergency contraceptives (ECs), ...

in the Yuzpe regimen.

Side effects

Pharmacology

Pharmacodynamics

Norgestrel is a

, or an

of the progesterone receptor. The

biological activity In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or ...

of norgestrel lies in the ''levo''

enantiomer In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical anti ...

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 ...

, whereas the ''dextro'' isomer is inactive. As such, norgestrel is identical in its hormonal activity to levonorgestrel except that it is half as potent by weight. Levonorgestrel, and by extension norgestrel, have some androgenic activity, but no

ic, antimineralocorticoid, or glucocorticoid activity. The ovulation-inhibiting dose of norgestrel appears to be greater than 75μg/day, as ovulation occurred in 50 to 75% of cycles with this dosage of norgestrel in studies. The ovulation-inhibiting dosage of levonorgestrel, which is twice as potent as norgestrel, is approximately 50 to 60μg/day. One review lists the ovulation-inhibiting dose of norgestrel as 100μg/day. The endometrial transformation dose of norgestrel is listed as 12mg per cycle and the

menstrual delay test Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of horm ...

dose of norgestrel is listed as 0.5 to 2mg/day.

Pharmacokinetics

The

pharmacokinetics Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered ...

of norgestrel have been reviewed.

Chemistry

Norgestrel, also known as ''rac''-13-ethyl-17α-ethynyl-19-nortestosterone or as ''rac''-13-ethyl-17α-ethynylestr-4-en-17β-ol-3-one, is a

estrane Estrane is a C18 steroid derivative, with a gonane core. ''Estrenes'' are estrane derivatives that contain a double bond, with an example being nandrolone. ''Estratrienes'' (estrins) are estrane derivatives that contain three double bonds, for i ...

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 ...

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. ...

testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...

. It is a

racemic mixture In chemistry, a racemic mixture, or racemate (), is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as racemates. ...

of stereoisomers dextronorgestrel (the C13α isomer; l-norgestrel, L-norgestrel, or (+)-norgestrel) and

(the C13β isomer; d-norgestrel, D-norgestrel, or (–)-norgestrel), the former of which is inactive (making norgestrel exactly half as potent as levonorgestrel). Norgestrel is more specifically a derivative of

norethisterone Norethisterone, also known as norethindrone and sold under many brand names, is a progestin medication used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders. The medication is available in b ...

(17α-ethynyl-19-nortestosterone) and is a member of the

gonane Gonane is a chemical compound with formula , whose molecule can be described as three molecules or entities of cyclohexane and one of cyclopentane, fused in a particular way. More specifically, the molecule can be described as that of cycloh ...

(18-methylestrane) subgroup 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 ...

family of progestins.

Synthesis

Chemical syntheses of norgestrel have been published.

History

Norgestrel was first introduced, as a birth control pill in combination with ethinylestradiol, under the brand name ''Eugynon'' in

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

in 1966. It was subsequently marketed as a combined birth control pill with ethinylestradiol in the United States under the brand name Ovral in 1968, and was marketed in many other countries as well.

Society and culture

Generic names

''Norgestrel'' is the generic name of the drug and its , , , , , , and . It is also known as ''dl-norgestrel'', ''DL-norgestrel'', or ''(±)-norgestrel''.

Brand names

Norgestrel has been marketed under a variety of brand names including Cyclacur, Cryselle, Cyclo-Progynova, Duoluton, Elinest, Eugynon, Microgynon, Lo/Ovral, Low-Ogestrel, Logynon, Microlut, Minicon, Nordette, Neogest, Ogestrel, Ovral, Ovran, Ovranette, Ovrette, Planovar, Prempak, Progyluton, and Trinordiol among others.

References

{{Progesterone receptor modulators Tertiary alcohols Ethynyl compounds Androgens and anabolic steroids Estranes Hormonal contraception Ketones Progestogens