A 30-year-old woman presents with amenorrhea after stopping oral contraceptives 6 months ago. She had normal puberty and regular menses until 18, when she started taking oral contraceptives. She reports stress at work. Her BMI is 21.3, and there is no galactorrhea, hirsutism, or acne. Pelvic exam is normal, pregnancy test is negative, prolactin is normal, and FSH is in the menopausal range. The diagnosis is primary ovarian insufficiency (POI), defined as amenorrhea for 4 months or more with two menopausal-range FSH levels. POI is a continuum of impaired ovarian function, not a binary state. It affects 1 in 100 women by 40. Causes are often unknown, but may include genetic factors, autoimmune disorders, or structural abnormalities. POI can be due to follicle dysfunction or depletion. Evaluation includes measuring prolactin, FSH, and thyrotropin. A progestin-withdrawal test is not recommended. Laboratory tests include karyotype, FMR1 premutation testing, adrenal antibodies, and pelvic ultrasound. Management includes hormone replacement therapy (estrogen and progestin) to prevent osteoporosis and cardiovascular disease. Patients should be educated on bone health, calcium and vitamin D intake, and weight-bearing exercise. Emotional support is important due to the impact of infertility. Family planning options include adoption, egg donation, or embryo donation. There is no known cure, but some women may conceive spontaneously. Patients with POI should be monitored for associated conditions like adrenal insufficiency, thyroid disease, or autoimmune disorders. Guidelines recommend estrogen replacement therapy and FMR1 premutation testing. The diagnosis should be discussed in person to address emotional concerns. Patients should keep a menstrual calendar and undergo regular screening for cardiovascular risk factors. Hormonal therapy should be continued until menopause. The average estradiol level in women with normal cycles is 100 pg/mL. Transdermal estradiol and cyclic medroxyprogesterone acetate are recommended. Bisphosphonates are not advised if pregnancy is possible. Patients should be informed about the risk of spontaneous remission and the options for family planning. The condition is associated with increased risk of osteoporosis and cardiovascular disease. Long-term risks and optimal management strategies remain uncertain.A 30-year-old woman presents with amenorrhea after stopping oral contraceptives 6 months ago. She had normal puberty and regular menses until 18, when she started taking oral contraceptives. She reports stress at work. Her BMI is 21.3, and there is no galactorrhea, hirsutism, or acne. Pelvic exam is normal, pregnancy test is negative, prolactin is normal, and FSH is in the menopausal range. The diagnosis is primary ovarian insufficiency (POI), defined as amenorrhea for 4 months or more with two menopausal-range FSH levels. POI is a continuum of impaired ovarian function, not a binary state. It affects 1 in 100 women by 40. Causes are often unknown, but may include genetic factors, autoimmune disorders, or structural abnormalities. POI can be due to follicle dysfunction or depletion. Evaluation includes measuring prolactin, FSH, and thyrotropin. A progestin-withdrawal test is not recommended. Laboratory tests include karyotype, FMR1 premutation testing, adrenal antibodies, and pelvic ultrasound. Management includes hormone replacement therapy (estrogen and progestin) to prevent osteoporosis and cardiovascular disease. Patients should be educated on bone health, calcium and vitamin D intake, and weight-bearing exercise. Emotional support is important due to the impact of infertility. Family planning options include adoption, egg donation, or embryo donation. There is no known cure, but some women may conceive spontaneously. Patients with POI should be monitored for associated conditions like adrenal insufficiency, thyroid disease, or autoimmune disorders. Guidelines recommend estrogen replacement therapy and FMR1 premutation testing. The diagnosis should be discussed in person to address emotional concerns. Patients should keep a menstrual calendar and undergo regular screening for cardiovascular risk factors. Hormonal therapy should be continued until menopause. The average estradiol level in women with normal cycles is 100 pg/mL. Transdermal estradiol and cyclic medroxyprogesterone acetate are recommended. Bisphosphonates are not advised if pregnancy is possible. Patients should be informed about the risk of spontaneous remission and the options for family planning. The condition is associated with increased risk of osteoporosis and cardiovascular disease. Long-term risks and optimal management strategies remain uncertain.