Acne is a problem of the pilo-sebaceous follicle caused by the conjunction of three factors: seborrhea, follicle obstruction, and follicle inflammation. The key element, seborrhea, is under androgenic control. Acne in women is also influenced by developments and modifications in genital life, as well as by hormonal contraceptive and replacement therapies. Acne is rare prior to puberty, when it may indicate endocrine disease. At puberty, acne is quasi-physiological, because of the relative hyperandrogenism induced by the andrenarche preceding pubarche, as well as by the relative shortage of estrogens and progesterone during the first menstrual cycles. Other signs of hyperandrogenism, such as menstrual cycle difficulties and excess weight, which favor a hormonal origin, must be sought in cases of persistent or late-onset acne in adults. There is a mirror image of puberty during the peri-menopausal period, but with decreased seborrhea, so acne is rare. Finally, a tumoral origin must be sought in the rare cases of acne occurring after menopause. Hormonal investigation of acne should not be systematic, but is justified during prepuberty when other symptoms are associated with acne that resists well-conducted dermatological treatment. The therapeutic approach should be primarily dermatological, but hormone-oriented treatment should be considered when such therapy fails, or in the presence of other signs of hyperandrogenism. Sometimes the association of isotretinoin and an anti-androgen treatment are necessary to effectively treat such acne. Finally, particular attention must be paid to contraceptive therapies and hormone treatments, which can induce or aggravate acne, especially during the peri-menopausal period.