Prostalene is an analogue of prostaglandin PGF-2 alpha. It is used for the control of estrus in mares.

Nomegestrol acetate (NOMAC) is a 19-norprogesterone derivative with high biological activity at the progesterone receptor, a weak anti-androgenic effect, but with no binding to estrogen, glucocorticoid or mineralocorticoid receptors. Nomegestrol has been developed by the Monaco-based company Théramex SAM (a Teva subsidiary). Nomegestrol acetate has been used successfully for the treatment of some gynaecological disorders (menstrual disturbances, dysmenorrhoea, premenstrual syndrome) and as a component of hormone replacement therapy in combination with estradiol for the relief of menopausal symptoms; it has been approved in Europe as monotherapy for the treatment of the menopausal syndrome, uterine diseases and menorrhagia, and in combination with an estrogen for the treatment of menopausal symptoms. Nomegestrol acetate in combination with estradiol is used as an oral contraceptive.

Algestone acetophenide, also known as dihydroxyprogesterone acetophenide, is an agonist of the progesterone receptor. Algestone acetophenide in combination with estradiol enanthate is sold under the brand name Deladroxate as a form of long-lasting injectable birth control. The combination provides simultaneously prolonged progestational and estrogenic activities both of which are maintained at effective levels for approximately three weeks after the intramuscular injection of a single dose.

Norelgestromin, the progestin, is the active metabolite of norgestimate and is structurally related to 19-nortestosterone. Norgestimate and norelgestromin mimic the physiologic effects of progesterone at the progesterone receptor. Johnson & Johnson developed an adhesive female contraceptive patch that contains ethinylestradiol (0.75mg) and the progestogen norelgestromin (6mg). his product is a combination contraceptive acting via the inhibition gonadotropins. Its primary mechanism of action involves the suppression of ovulation, including changes in the cervical mucus and endometrium. The patch delivers a continuous flow of hormones through the skin and into the bloodstream. The contraceptive patch is available in countries worldwide.

Laureth 10S is a vaginal contraceptive drug. This agent is capable to interact with the lipoprotic membrane of spermatozoa.

Estetrol is the natural human fetal selective estrogen receptor modulator. It is synthesized exclusively by the human fetal liver during pregnancy. Estetrol has a moderate affinity for human estrogen A receptor (ERa) and estrogen B receptor (ERb). Estetrol may be suitable as a potential drug for human use in applications such as hormone replacement therapy (vaginal atrophy, hot flushes), contraception and osteoporosis. The most common drug-related adverse events were lower abdominal pain, nausea, headache, dysmenorrhoea, breast enlargement and acne. Estetrol had been in clinical trials for the treatment of breast and prostate cancers.

Segesterone acetate (elcometrine), a progestin, is sold in combination with ethinyl estradiol under the brand name Annovera. Annovera is indicated for use by females of reproductive potential to prevent pregnancy. Segesterone acetate acts as an agonist of the progesterone receptor and it doesn’t possess estrogenic, androgenic, antiandrogenic, or antimineralocorticoid activity.

Ulipristal acetate (also known as CDB-2914 and PGL4001 and trade name Ella in the U.S) is a novel oral emergency contraceptive designed and developed by HRA Pharma. It is a selective progesterone receptor modulator, which reversibly blocks the progesterone receptors in target tissues it was approved in May 2009 by the European Commission and in August 2010 by the FDA as safe and effective in preventing unintended pregnancy for up to 120 hours – or five days – post- unprotected intercourse or contraceptive failure. Ella is not intended for routine use as a contraceptive. When taken immediately before ovulation is to occur, ella postpones follicular rupture. The likely primary mechanism of action of ulipristal acetate for emergency contraception is therefore inhibition or delay of ovulation; however, alterations to the endometrium that may affect implantation may also contribute to efficacy. The most common side effects are: headache, nausea, stomach (abdominal) pain, menstrual pain. Some women taking ella may have their next period earlier or later than expected. If your period is more than a week late, you should get a pregnancy test.

Levonorgestrel (LNG) is a synthetic progestational hormone with actions similar to those of progesterone and about twice as potent as its racemic or (+-)-isomer (norgestrel). It is used for contraception, control of menstrual disorders, and treatment of endometriosis. It is usually supplied in a racemic mixture (Norgestrel, 6533-00-2). Only the levonorgestrel isomer is active. Within an Intrauterine device (IUD), sold as Mirena among others, it is effective for long term prevention of pregnancy. The local mechanism by which continuously released LNG enhances contraceptive effectiveness of Mirena has not been conclusively demonstrated. Studies of Mirena and similar LNG IUS prototypes have suggested several mechanisms that prevent pregnancy: thickening of cervical mucus preventing passage of sperm into the uterus, inhibition of sperm capacitation or survival, and alteration of the endometrium. Mirena has mainly local progestogenic effects in the uterine cavity. The high local levels of levonorgestrel lead to morphological changes including stromal pseudodecidualization, glandular atrophy, a leukocytic infiltration and a decrease in glandular and stromal mitoses. Ovulation is inhibited in some women using Mirena. In a 1-year study, approximately 45% of menstrual cycles were ovulatory, and in another study after 4 years, 75% of cycles were ovulatory. There has been much debate regarding levonorgestrel emergency contraception's (LNG-EC's) method of action since 1999 when the Food and Drug Administration first approved its use. Proponents of LNG-EC have argued that they have moral certitude that LNG-EC works via a non-abortifacient mechanism of action, and claim that all the major scientific and medical data consistently support this hypothesis. However, newer medical data serve to undermine the consistency of the non-abortifacient hypothesis and instead support the hypothesis that preovulatory administration of LNG-EC has significant potential to work via abortion. The implications of the newer data have important ramifications for medical personnel, patients, and both Catholic and non-Catholic emergency room protocols. In the future, technology such as the use of early pregnancy factor may have the potential to quantify how frequently preovulatory LNG-EC works via abortion. The latest scientific and medical evidence now demonstrates that levonorgestrel emergency contraception theoretically works via abortion quite often. The implications of the newer data have important ramifications for medical personnel, patients, and both Catholic and non-Catholic emergency room rape protocols.

Levonorgestrel (LNG) is a synthetic progestational hormone with actions similar to those of progesterone and about twice as potent as its racemic or (+-)-isomer (norgestrel). It is used for contraception, control of menstrual disorders, and treatment of endometriosis. It is usually supplied in a racemic mixture (Norgestrel, 6533-00-2). Only the levonorgestrel isomer is active. Within an Intrauterine device (IUD), sold as Mirena among others, it is effective for long term prevention of pregnancy. The local mechanism by which continuously released LNG enhances contraceptive effectiveness of Mirena has not been conclusively demonstrated. Studies of Mirena and similar LNG IUS prototypes have suggested several mechanisms that prevent pregnancy: thickening of cervical mucus preventing passage of sperm into the uterus, inhibition of sperm capacitation or survival, and alteration of the endometrium. Mirena has mainly local progestogenic effects in the uterine cavity. The high local levels of levonorgestrel lead to morphological changes including stromal pseudodecidualization, glandular atrophy, a leukocytic infiltration and a decrease in glandular and stromal mitoses. Ovulation is inhibited in some women using Mirena. In a 1-year study, approximately 45% of menstrual cycles were ovulatory, and in another study after 4 years, 75% of cycles were ovulatory. There has been much debate regarding levonorgestrel emergency contraception's (LNG-EC's) method of action since 1999 when the Food and Drug Administration first approved its use. Proponents of LNG-EC have argued that they have moral certitude that LNG-EC works via a non-abortifacient mechanism of action, and claim that all the major scientific and medical data consistently support this hypothesis. However, newer medical data serve to undermine the consistency of the non-abortifacient hypothesis and instead support the hypothesis that preovulatory administration of LNG-EC has significant potential to work via abortion. The implications of the newer data have important ramifications for medical personnel, patients, and both Catholic and non-Catholic emergency room protocols. In the future, technology such as the use of early pregnancy factor may have the potential to quantify how frequently preovulatory LNG-EC works via abortion. The latest scientific and medical evidence now demonstrates that levonorgestrel emergency contraception theoretically works via abortion quite often. The implications of the newer data have important ramifications for medical personnel, patients, and both Catholic and non-Catholic emergency room rape protocols.