Progestogen Only Pills or Progestin Only Pills (POP) are contraceptive pills that only contain synthetic progestogens (progestins) and do not contain oestrogen. They are colloquially known as mini pills. Common disk-shaped pills A pharmacological tablet is a medicinal or other active substance mixed with binder powders and pressed into a tablet form. ... Progestagens (also spelled progestogens or gestagens) are hormones similar in effect to progesterone, the only natural progestagen. ... A progestin is a synthetic progestagen. ... Estrogens (or oestrogens) are a group of steroid compounds that function as the primary female sex hormone. ...

Although such pills are sometimes called "Progesterone Only Pills," they do not actually contain progesterone, but one of several chemically related compounds and there are a number of progestogen only contraceptive formulations. Progesterone is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy (supports gestation) and embryogenesis of humans and other species. ... Oral contraceptives come in a variety of formulations. ...

How they work

The mechanism of action of progestogen-only contraceptives depends on the progestogen activity and dose.^[1] Progestagens (also spelled progestogens or gestagens) are hormones similar in effect to progesterone, the only natural progestagen. ...

Very low dose progestogen-only contraceptives, such as traditional progestogen-only pills (and subdermal implants Norplant and Jadelle and intrauterine systems Progestasert and Mirena), inconsistently inhibit ovulation in ~50% of cycles and rely mainly on their progestogenic effect of thickening the cervical mucus and thereby reducing sperm viability and penetration. Norplant is a form of birth control released in 1991 by Wyeth Pharmaceuticals, consisting of a set of six small, silicone capsules filled with levonorgestrel, a synthetic progestin used in many birth control pills. ... The IntraUterine System or IUS is an IntraUterine Device (IUD or coil) that has a coating of levonorgestrel (a progesterone) on its shaft, rather than the traditional copper wire. ...

Intermediate dose progestogen-only contraceptives, such as the progestogen-only pill Cerazette (or the subdermal implant Implanon), allow some follicular development but much more consistently inhibit ovulation in 97–99% of cycles. The same cervical mucus changes occur as with very low dose progestogens. Implanon, made by Organon International, is a contraceptive technology that is inserted under the skin of a womans upper arm. ...

High dose progestogen-only contraceptives, such as the injectables Depo-Provera and Noristerat, completely inhibit follicular development and ovulation. The same cervical mucus changes occur as with very low dose and intermediate dose progestogens. Depo-Provera is a contraceptive or birth control product which is injected every 3 months. ...

In anovulatory cycles using progestogen-only contraceptives, the endometrium is thin and atrophic. If the endometrium was also thin and atrophic during an ovulatory cycle, this could theoretically interfere with implantation of a blastocyst (embryo).

Efficacy

The theoretical efficacy is similar to that of the combined oral contraceptive pill (COCP). However, they are taken continuously without any breaks between packets and traditional progestogen-only pills must be taken to a much stricter time every day (within 3 hours vs. a COCP's 12 hours, although in some countries the POP Cerazette has an approved window of 12 hours). The real-life efficacy is therefore dependent upon user compliance. The combined oral contraceptive pill, often referred to as the Pill, is a combination of an estrogen and a progestin, taken by mouth to inhibit normal fertility. ...

POPs are not dependent upon gut bacterial flora for their absorption and so are not affected by courses of antibiotics. They will, however, be affected by any episodes of diarrhoea or vomiting. In microbiology, flora (plural: floras or floræ) refers to the collective bacteria and other microorganisms in an ecosystem (usually an animal host or a single part of its body). ... An antibiotic is a drug that kills or slows the growth of bacteria. ...

Benefits

Lacking the oestrogen of combined pills, they are not associated with increased risks of DVT or heart disease. With the decreased clotting risk, they are not contraindicated in the setting of sickle-cell disease. The low dose of progestogen, and absence of oestrogen, make the minipill safe to use during breastfeeding; in fact, it may increase the flow of milk. Like combined pills, the minipill decreases the likelihood of pelvic inflammatory disease. Estrogens (or oestrogens) are a group of steroid compounds that function as the primary female sex hormone. ... DTV Is a software program used for watching online television A.K.A. Videocasts It can also stand for deep vein thrombosis ... Heart disease is an umbrella term for a number of different diseases which affect the heart. ... Sickle-cell disease is a general term for a group of genetic disorders caused by sickle hemoglobin (Hgb S or Hb S). ... Breastfeeding an infant Symbol for breastfeeding (Matt Daigle, Mothering magazine contest winner 2006) Breastfeeding is the process of a woman feeding an infant or young child with milk from her breasts. ... A glass of cows milk Milk is the nutrient fluid produced by the mammary glands of female mammals (including monotremes). ... Pelvic inflammatory disease (or disorder) (PID) is a generic term for infection of the female uterus, fallopian tubes, and/or ovaries. ...

It is unclear whether POPs provide protection against endometrial cancer and ovarian cancer to the extent that COCP do. Endometrial cancer involves cancerous growth of the endometrium (lining of the uterus). ... Ovarian cancer is a malignant ovarian neoplasm (an abnormal growth located on the ovaries). ...

Side effects

• With no break in the dosage, bleeds do not initially occur at a predictable time. Most women tend to establish, over a few months, light spotting at approximately regular intervals.
• May cause mastalgia or mood swings.
• Weight gain is less commonly experienced than on COCP.

Medically meaning Breast (mast-) pain (-algia) Its can be subdivided into 2 main clinical patterns: cyclical when the pain is worse prior to each menstrual cycle This may occur with a womans natural menstrual cycles and is not due to any hormone or breast disease. ...

Breast cancer risk

Epidemiological evidence on POPs and breast cancer risk is based on much smaller populations of users and so is less conclusive than that for COCPs.

In the largest (1996) reanalysis of previous studies of hormonal contraceptives and breast cancer risk, less than 1% were POP users. Current or recent POP users had a slightly increased relative risk (RR 1.17) of breast cancer diagnosis that just missed being statistically significant. The relative risk was similar to that found for current or recent COCP users (RR 1.16), and as with COCPs, the increased relative risk decreased over time after stopping, vanished after 10 years, and was consistent with being due to earlier diagnosis or promoting the growth of a preexisting cancer.^[2][3]

The most recent (1999) IARC evaluation of progestogen-only hormonal contraceptives reviewed the 1996 reanalysis as well as 4 case-control studies of POP users included in the reanalysis. They concluded that: "Overall, there was no evidence of an increased risk of breast cancer" with progestogen-only contraceptives, but since there was "inadequate evidence", they were "possibly carcinogenic".^[4] The International Agency for Research on Cancer (IARC, or CIRC in its French acronym) is an intergovernmental agency forming part of the World Health Organisation of the United Nations. ...

Recent anxieties about the contribution of progestogens to the increased risk of breast cancer associated with HRT in postmenopausal women such as found in the WHI trials^[5] have not yet spread to progestogen-only contraceptive use in premenopausal women.^[1] Hormone replacement therapy (HRT) is a system of medical treatment for perimenopausal and postmenopausal women, based on the assumption that it may prevent discomfort and health problems caused by diminished circulating estrogen hormones. ... The Womens Health Initiative (WHI) was initiated by the National Institutes of Health (NIH) in 1991. ...

See also

• Emergency contraception ('Morning-after pill')
• Oral contraceptive formulations
• Progestin

Wikinews has news related to: FDA to move on approval of over-the-counter sale of Plan B birth control Emergency contraception (EC) (also known as Emergency Birth Control (EBC), the morning-after pill, or postcoital contraception) refers to measures that, if taken after sex, may prevent pregnancy. ... Oral contraceptives come in a variety of formulations. ... A progestin is a synthetic progestagen. ...

Footnotes