From Wikipedia, the free encyclopedia
Estrone (top) and
progesterone (bottom)
Combination of
Clinical data
Trade namesSynergon[1][2]
Other namesE1/P4
Routes of
Intramuscular injection

Estrone/progesterone (E1/P4), sold under the brand name Synergon, is a combination medication formulation of estrone, an estrogen, and progesterone, a progestogen, which is used as an injectable preparation to induce withdrawal bleeding in women with non-pregnancy-related amenorrhea (absence of menstruation).[3][1][2][4] [5][6] It has also sometimes been used off-label as an abortifacient.[5][6][7] The medication comes in a three-ampoule pack, contains 1 mg estrone and 10 mg progesterone per ampoule, and is administered by intramuscular injection.[3][5][6][8] The usual dose of the medication is three injections each two days apart, with the treatment duration not exceeding one week.[3] E1/P4 is or has been available in France, Monaco, and Turkey, as well as in some French-speaking African countries such as Benin and Cameroon.[1][2][4][9][6][7] The medication has been marketed since at least 1952.[10]

See also[edit]


  1. ^ a b c "Estrone". Archived from the original on 2018-06-21. Retrieved 2019-04-12.
  2. ^ a b c "Progesterone". Retrieved 2019-04-12.
  3. ^ a b c[full citation needed]
  4. ^ a b Sweetman, Sean C., ed. (2009). "Sex hormones and their modulators". Martindale: The Complete Drug Reference (36th ed.). London: Pharmaceutical Press. pp. 2101, 2127. ISBN 978-0-85369-840-1. Estrone [...] Progesterone [...] Multi-ingredient: [...] Fr.: Synergon [...] Turk.: Synergon
  5. ^ a b c Addo VN, Tagoe-Darko ED (June 2009). "Knowledge, practices, and attitudes regarding emergency contraception among students at a university in Ghana". Int J Gynaecol Obstet. 105 (3): 206–9. doi:10.1016/j.ijgo.2009.01.008. PMID 19232600. S2CID 22216977. Synergon, a combination of progesterone and oestrone in an injectable form, is marketed to induce withdrawal bleeding in women with nongravid amenorrhea; however, it can be used as an arbortifacient [11].
  6. ^ a b c d Kongnyuy EJ, Ngassa P, Fomulu N, Wiysonge CS, Kouam L, Doh AS (July 2007). "A survey of knowledge, attitudes and practice of emergency contraception among university students in Cameroon". BMC Emerg Med. 7: 7. doi:10.1186/1471-227X-7-7. PMC 1933435. PMID 17634106. Synergon is dedicated product made up of a combination of progesterone and oestrone in an injectable form. It is used to induce withdrawal bleeding in cases of non-gravid amenorrhoea. In Cameroon, synergon is widely used among students as an abortifacient and is usually administered clandestinely by nurses when a woman presents with amenorrhoea. Such an attitude stemmed from the fact that this product induces withdrawal bleeding, so that some cases of amenorrhoea falsely believed to be due pregnancy are resolved by one or a few intramuscular injections of Synergon. We are not aware of similar findings reported from other countries. Synergon is not produced by the manufacturer as an abortifacient; how it came to be associated with abortion in Cameroon is not known. It is also not known whether it actually induces abortion or it only induces withdrawal bleeding in women with non-gravid amenorrhoea.
  7. ^ a b Baxerres C, Boko I, Konkobo A, Ouattara F, Guillaume A (February 2018). "Abortion in two francophone African countries: a study of whether women have begun to use misoprostol in Benin and Burkina Faso". Contraception. 97 (2): 130–136. doi:10.1016/j.contraception.2017.10.011. PMID 29104024. It is not hard to find [abortion] services in Cotonou [Benin]. [...] The most commonly used method was [manual vacuum aspiration], followed by curettage, and more rarely a Synergon® (progesterone + estrone) injection, a product indicated in the symptomatic treatment of non-gravid amenorrhea.8
  8. ^ Kathleen McDonnell (1986). Adverse Effects: Women and the Pharmaceutical Industry. International Organization of Consumers Unions, Regional Office for Asia and the Pacific. p. 15. ISBN 978-967-9973-17-4. Synergon. 10 mg progesterone. 1 mg folliculine [estrone].
  9. ^[permanent dead link][full citation needed]
  10. ^ Endokrinologie. Johann Ambrosius Barth Verlag. 1952. Synergon. Progesterone + Follikulin [Estrone]. Amp. Lab. Hépat.