Progestogen-only injectable contraceptives (POICs) are a form of

hormonal contraception 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 original ...

and progestogen-only contraception that are administered by

injection Injection or injected may refer to: Science and technology * Injective function, a mathematical function mapping distinct arguments to distinct values * Injection (medicine), insertion of liquid into the body with a syringe * Injection, in broadca ...

and providing long-lasting

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

. As opposed to combined injectable contraceptives, they contain only a

progestogen Progestogens, also sometimes written progestins, 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 progestoge ...

without an

estrogen Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...

, and include two

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. ...

preparations: *

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 ...

(brand names Depo-Provera, Provera, Depo-subQ Provera 104) – 150 mg (

intramuscular 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 ...

ly) or 104 mg ( subcutaneously) every 3 months *

Norethisterone enanthate Norethisterone enanthate (NETE), also known as norethindrone enanthate, is a form of hormonal birth control which is used to prevent pregnancy in women. It is used both as a form of progestogen-only injectable birth control and in combined inje ...

(brand names NET EN, Noristerat, Norigest, Doryxas) – 200 mg (intramuscularly) every 2 months

Mechanism of action

These POICs work by providing an influx of

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 ma ...

into the female body. This influx will signal to the body that it does not need to synthesize its own hormones to induce the cycle. Since the body does not release any hormones of its own, there are no fluctuations in levels to trigger the phases in menstruation and

ovulation Ovulation is an important part of the menstrual cycle in female vertebrates where the egg cells are released from the ovaries as part of the ovarian cycle. In female humans ovulation typically occurs near the midpoint in the menstrual cycle and ...

does not occur.

Potential side effects

As will all

medications, certain

side effects In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually used ...

may occur from taking the hormonal supplements. Changes in menstrual bleeding may occur, such as a lighter flow or complete stop to the regular monthly

menses Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and Mucous membrane, mucosal tissue from the endometrium, inner lining of the uterus through the vagina. The menstrual cycle is characterized ...

, or abnormal bleeding throughout the cycle. Others have reported small weight gain, and increase in headaches or mood swings, and a decrease in

libido In psychology, libido (; ) is psychic drive or energy, usually conceived of as sexual in nature, but sometimes conceived of as including other forms of desire. The term ''libido'' was originally developed by Sigmund Freud, the pioneering origin ...

Links to cancer

Some research has shown that women who have taken hormonal birth controls could possible be less likely to develop certain cancers, such as endometrial, cervical, and ovarian. This is likely due to the fact that the hormonal birth controls stop the monthly cycle of injury and repair to the endometrial tissue. This consistent injury to the uterine tissues is thought to be a factor in developing certain cancers, so if it is stopped for a period of time, the tissue will be less damaged than that of someone who has never taken birth control. On the contrary, it was shown that women who has previously or were currently taking a hormonal birth control had an increased risk in developing breast cancer. This risk decreased as the individuals stopped the birth control, but no data was found linked to the duration of time one was taking a

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

Research

Progestogens that have been studied for potential use as POICs but were never marketed as such include the

derivatives

algestone acetophenide Algestone acetophenide, also known more commonly as dihydroxyprogesterone acetophenide (DHPA) and sold under the brand names Perlutal and Topasel among others, is a progestin medication which is used in combination with an estrogen as a form ...

(dihydroxyprogesterone acetophenide) (100 mg/month), chlormadinone acetate (250 mg/3 months),

hydroxyprogesterone caproate Hydroxyprogesterone caproate, sold under the brand name Delalutin among others, is a medication used to reduce the risk of preterm birth in women pregnant with one baby who have a history of spontaneous preterm birth. In March 2023, the manuf ...

(250–500 mg/month), gestonorone caproate (2.5–200 mg/1–2 months), and oxogestone phenpropionate (50–75 mg/month), and the

testosterone Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...

derivatives lynestrenol phenylpropionate (25–75 mg/month), levonorgestrel butanoate, levonorgestrel cyclobutylcarboxylate, and levonorgestrel cyclopropylcarboxylate. Some of these have been introduced for use in combined injectable contraceptives instead.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

References

{{Progesterone receptor modulators Hormonal contraception Progestogens

Mechanism of action

Potential side effects

Links to cancer

Research

See also

References