Norgestrel, sold under the brand name Opill among others, is a progestin which is used in birth control pills. It is often combined with the estrogen ethinylestradiol, marketed as Ovral. It is also used in menopausal hormone therapy.
of norgestrel include menstrual irregularities, , nausea, and breast tenderness.
Norgestrel was patented in 1961 and came into medical use, specifically in birth control pills, in 1966.[ ]
Medical uses
Norgestrel is used in combination with
ethinylestradiol or
quinestrol in combined birth control pills, 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 in the
Yuzpe regimen.
Side effects
Pharmacology
Pharmacodynamics
Norgestrel is a progestogen, or an
agonist of the progesterone receptor.
The biological activity of norgestrel lies in the
levo enantiomer,
levonorgestrel, 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
activity, but no estrogenic, 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.
Pharmacokinetics
The
pharmacokinetics 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 synthetic
estrane steroid and a derivative of
testosterone.
It is a
racemic mixture of
dextronorgestrel (the C13α isomer; l-norgestrel, L-norgestrel, or (+)-norgestrel) and
levonorgestrel (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 (17α-ethynyl-19-nortestosterone) and is a member of the
gonane (18-methylestrane) subgroup of the 19-nortestosterone 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 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.
The contraceptive efficacy of norgestrel was established in the U.S. with the original approval for prescription use in 1973.
In July 2023, the FDA approved norgestrel for over-the-counter sale.
Society and culture
Generic names
Norgestrel is the
generic term of the drug and its international nonproprietary name, United States Adopted Name, United States Pharmacopeia, British Approved Name, Dénomination Commune Française, Denominazione Comune Italiana, and Japanese Accepted Name.
It is also known as dl-norgestrel, DL-norgestrel, or (±)-norgestrel.
Brand names
Norgestrel is 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, Opill, Ogestrel, Ovral, Ovran, Ovranette, Ovrette, Planovar, Prempak, Progyluton, and Trinordiol among others.
