Estrone/progesterone

Estrone/progesterone (E1/P4), sold under the brand name Synergon, is a combination medication formulation of estrone, an estrogen, and progesterone, a progestogen. E1/P4 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][7]} It has also sometimes been used off-label as an abortifacient.^[5][6][8] 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][9] 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][10][6][8]} The medication has been marketed since at least 1952.^[11]

Estrone/progesterone

Estrone (top) and progesterone (bottom)
Combination of
Estrone	Estrogen
Progesterone	Progestogen
Clinical data
Trade names	Synergon[1][2]
Other names	E1/P4
Routes of administration	Intramuscular injection

See also

• Estradiol/progesterone
• Estradiol benzoate/progesterone
• Estradiol hemisuccinate/progesterone
• List of combined sex-hormonal preparations