Normal FSH levels vary based on age, sex, and menstrual cycle phase. For adult females, typical ranges are:

• Follicular phase: 2.5–10.2 mIU/mL

• Mid-cycle peak: 3.1–17.7 mIU/mL

• Luteal phase: 1.5–9.1 mIU/mL

• Postmenopausal: 23.0–116.3 mIU/mL

For adult males, a normal range is approximately 1.4–12.8 mIU/mL.