Norethisterone enanthate (brand names NET EN, Noristerat, Norigest, Doryxas)[5] – 200 mg (intramuscularly) every 2 months[3]
Mechanism of Action
These POICs work by providing an influx of progesterone 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 does not occur. [6]
Potential Side Effects
As will all birth control medications, certain side effects 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, or abnormal bleeding throughout the cycle. Others have reported small weight gain, and increase in headaches or mood swings, and a decrease in libido.[6]
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.[7] 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 that 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. [7]
^Singh M, Saxena BB, Singh R, Kaplan J, Ledger WJ (1997). "Contraceptive efficacy of norethindrone encapsulated in injectable biodegradable poly-dl-lactide-co-glycolide microspheres (NET-90): phase III clinical study". Advances in Contraception. 13 (1): 1–11. doi:10.1023/a:1006519027168. PMID9181181. S2CID44918557. In 1957, Karl Junkmann developed norethindrone enanthate (NET-EN or Noristeroir), the first injectable contraceptive which was injected every two months [1].
^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