LH FSH RATIO

LH/FSH ratio under 1 means FSH is higher than LH. This can be normal in the early follicular phase or with hormonal contraception, but may also reflect decreased ovarian reserve, perimenopause/primary ovarian insufficiency, or hypothalamic dysfunction. Clinical context matters. Your clinician may repeat tests, check AMH and antral follicle count, and consider fertility or endocrine evaluation to guide management.

The LH/FSH ratio helps evaluate reproductive and pituitary function: it reflects ovulation status, ovarian reserve, and hormonal balance. An elevated ratio (often >2) is commonly seen in polycystic ovary syndrome and suggests disrupted ovulation; low or abnormal ratios point to pituitary or gonadal dysfunction. Clinicians use it with symptoms and other tests to diagnose infertility, menstrual irregularities, and guide treatment.

For women trying to conceive, an early-follicular FSH under about 10 IU/L generally indicates good ovarian reserve; 10–20 IU/L is borderline and >20 IU/L suggests poor reserve. Basal LH in the follicular phase is typically around 2–15 IU/L. A markedly high LH or an LH:FSH ratio above ~2 may indicate PCOS and can impair fertility. Interpret results with age and clinical context.

No. An elevated LH:FSH ratio was once considered a clue for PCOS, but it’s neither sensitive nor specific and is not diagnostic. The ratio varies with cycle timing, age, obesity and metabolic factors. PCOS is diagnosed clinically and by ultrasound (e.g., oligo/anovulation, hyperandrogenism, polycystic ovaries) after excluding other causes; the LH:FSH ratio may be supportive but not definitive.

A low LH:FSH ratio usually reflects reduced LH secretion rather than a lab fluke. Common causes include hypothalamic suppression from stress, low weight or excess exercise, high prolactin, pituitary dysfunction, certain medications or hormonal disorders. Timing within the menstrual cycle and lab variability matter. Low LH can impair ovulation, so see a clinician for repeat tests, prolactin/TSH checks and possible imaging or treatment.

Yes—diet can influence the LH/FSH ratio, especially in conditions like PCOS. High‑calorie, high‑refined‑carbohydrate diets promote insulin resistance, which can raise ovarian androgen production and disturb LH/FSH balance. Weight loss, low‑glycemic/balanced eating and correcting nutrient deficiencies (e.g., vitamin D) often help normalize hormones. Work with a clinician for testing and tailored management.