Some of the women experienced side effects from "the pill" (Enovid) and Rice-Wray wrote Pincus and reported that Enovid "gives one hundred percent protection against pregnancy but causes too many side reactions to be acceptable".
In general, pregnane derivatives (progesterone, dydrogesterone, 17α-hydroxyprogesterone caproate, medroxyprogesterone acetate, megestrol acetate, etc.) do not virilize even in high dose; testosterone derivatives (ethisterone) and 19-nortestosterone (norethisterone, norethisterone acetate, etc.) generally virilize, but there are exceptions (e.g. norethynodrel) that do not.