Background: Physicians and menstruating women often ask pharmacists for recommendations about menstrual cycle–related problems. Progesterone and medroxyprogesterone may provide physiology-based treatment, but official indications in menstruating women in Canada are minimal. Objectives: To describe pharmacists' responses to vignette-based questions about the treatment of common clinical problems in menstruating women and review evidence-based therapies. Methods: A pharmacist interviewer administered an 11-item questionnaire to a random sample of community pharmacists. Questions were based on clinical vignettes in adolescent, pre- and perimenopausal women and related to heavy flow, polycystic ovary syndrome, premenopausal osteoporosis, perimenopausal night sweats and side effects/contraindications for estrogens and progesterone/progestins. Results: The participation rate was 58%, including equal numbers of male and female pharmacists. Seventy-two percent indicated that they would treat menorrhagia in an anemic 13-year-old with oral contraceptives — 21% would recommend ibuprofen and 86% iron. Half recommended that a 35-year-old smoker with heavy flow and acne stop oral contraceptives, but the other 50% recommended a switch to an oral contraceptive with cyproterone. For premenopausal osteoporosis, the majority recommended calcium and vitamin D, but 53% endorsed oral contraceptives — only 7% suggested cyclic medroxyprogesterone. For night sweats, the majority recommended progesterone/progestin in a regularly menstruating 42-year-old woman. Estrogens are contraindicated with past thrombosis and/or breast cancer family history, and they could cause nausea; 50% of pharmacists also attributed these adverse effects to progesterone/progestins. Conclusions: Community pharmacists vary widely in their treatment choices for common pre- and perimenopausal women's menstrual cycle–related problems. The evidence in support of most recommendations is minimal or lacking.