Tanaproget polymorph Form II, processes for preparing tanaproget polymorph Form II, pharmaceutical compositions including tanaproget polymorph Form II, micronized tanaproget polymorph Form II, and processes for converting Form II to tanaproget Form I are provided. Also provided are methods of contraception, hormone replacement therapy, stimulation of food intake and treating or preventing uterine myometrial fibroids, benign prostatic hypertrophy, benign and malignant neoplastic disease, dysfunctional bleeding, uterine leiomyomata, endometriosis, polycystic ovary syndrome, or carcinomas and adenocarcinomas comprising administering polymorph Form II to a mammalian subject.