What is Estradiol benzoate/estradiol valerate/hydroxyprogesterone caproate?

Estradiol benzoate/estradiol valerate/hydroxyprogesterone caproate , sold under the brand name Sin-Ol, is a combination medication of estradiol benzoate , an estrogen, estradiol valerate , an estrogen, and hydroxyprogesterone caproate , 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.