A 39-week oral toxicity study of ulipristal acetate in cynomolgus monkeys

► Morphological changes are limited to findings in uterine endometrium and oviducts. ► Endometrium findings are similar to PRM-associated-endometrial-changes in women. ► No adverse effects were found that would raise concerns about pre-malignancy. ► Partial or complete recovery was observed for all effects.