The normal female life cycle is associated with a number of hormonal milestones: menarche, pregnancy, contraceptive use, menopause, and the use of replacement sex hormones. Menarche marks the onset of menses and cyclic changes in hormone levels. Pregnancy is associated with rising noncyclic levels of sex hormones, and menopause with declining noncyclic levels. Hormonal contraceptive use during the reproductive years and hormone replacement in menopause are therapeutic hormonal interventions that alter the levels and cycling of sex hormones. These events and interventions may cause a change in the prevalence or intensity of headache. The menstrual cycle is the result of a carefully orchestrated sequence of interactions between the hypothalamus, pituitary, ovary, and endometrium, with the sex hormones acting as modulators and effectors at each level. Estrogen and progestins have potent effects on central serotonergic and opioid neurons, modulating both neuronal activity and receptor density. The primary trigger of Menstrually-related migraine (MM) appears to be the withdrawal of estrogen rather than the maintenance of sustained high or low estrogen levels. However, changes in the sustained estrogen levels with pregnancy (increased) and menopause (decreased) appear to affect headaches. Headaches associated with OC use or menopausal hormonal replacement therapy may be related, in part, to periodic discontinuation of oral sex hormone preparations. The treatment of migraine associated with changes in sex hormone levels is frequently difficult and the patients are often refractory to therapy. Based on what is known of the pathophysiology of migraine, we have attempted to provide a logical approach to the treatment of headaches that are associated with menses, menopause, and OCs using abortive and preventive medications and hormonal manipulations. Considerable evidence suggests a link between estrogen and progesterone, the female sex hormones, and migraine. (Silberstein and Merriam, 1997; Lipton and Stewart, 1993; Epstein et al., 1975; Goldstein and Chen, 1982; Selby and Lance, 1960) Although no gender difference is apparent in prepubertal children, with migraine occurring equally in 4p. 100 of boys and girls, (Goldstein and Chen, 1982, Waters and O'Connor, 1971) migraine occurs more frequently in adult women (18p. 100) than in men (6p. 100). (Lipton and Stewart, 1993) Migraine develops most frequently in the second decade, with the peak incidence occurring with adolescence. (Selby and Lance, 1960; Epstein et al., 1975) Menstrually-related migraine (MM) begins at menarche in 33p. 100 of affected women (Epstein et al. , 1975). MM occurs mainly at the time of menses in many migrainous women, and exclusively with menses (true menstrual migraine [TMM]) in some (Epstein et al., 1975). Menstrual migraine can be associated with other somatic complaints arising before and often persisting into menses, such as nausea, backache, breast tenderness, and cramps and like them appears to be the result of falling sex hormone levels (Silberstein and Merriam, 1997; American Psychiatric Association, 1994). In addition, premenstrual migraine can be associated with premenstrual dysphoric disorder (PDD), also called "premenstrual syndrome" (PMS), which is distinct from the physical symptoms of the perimenstrual period and is probably not directly driven by declining progesterone levels (Mortola, 1998). Migraine occurring during (rather than prior to) menstruation is usually not associated with PMS (Silberstein and Merriam, 1997). Migraine may worsen during the first trimester of pregnancy and, although many women become headache-free during the last two trimesters, 25p. 100 have no change in their migraine (Silberstein, 1997). MM typically improves with pregnancy, perhaps due to sustained high estrogen levels (Silberstein, 1997). Hormonal replacement with estrogens can exacerbate migraine and oral contraceptives (OCs) can change its character and frequency