Estradiol benzoate/estradiol valerate/hydroxyprogesterone caproate (EB/EV/OHPC), sold under the brand name Sin-Ol, is a combination medication of estradiol benzoate (EB), an estrogen, estradiol valerate (EV), an estrogen, and hydroxyprogesterone caproate (OHPC), a progestin, which was reportedly used as a combined injectable contraceptive in women in the early 1970s. It contained 1 mg EB, 10 mg EV, and 250 mg OHPC in oil solution, was provided in the form of 3 mL ampoules, and was administered by intramuscular injection at regular intervals. The medication was manufactured by the pharmaceutical company Reuffer in Mexico. See also Estradiol benzoate/estradiol phenylpropionate Estradiol/estradiol enanthate List of combined sex-hormonal preparations § Estrogens and progestogens References Abandoned drugs Combined estrogen–progestogen formulations Combined injectable contraceptives