Estradiol & FSH
Also known as:
E2, follicle-stimulating hormone
Useful for early menopause and missed periods. Rarely needed to diagnose perimenopause after 45.
Written and reviewed by Farhan Tahir, MD · Last reviewed
VIDEO LESSON
What it measures
Estradiol is the main estrogen made by the ovaries. FSH is the pituitary signal that drives follicle growth; it rises when the ovaries respond less.
When it helps
• Suspected premature ovarian insufficiency or early menopause (under 40 to 45)
• Absent periods, to separate ovarian from pituitary or hypothalamic causes
• Selected fertility and treatment situations
When it doesn't
In perimenopause after 45, both hormones swing from day to day, so one result can look normal, high or low. NICE advises diagnosing perimenopause and menopause clinically in this age group.
Reading the results
• High FSH with low estradiol: the ovaries are not responding (ovarian insufficiency).
• Low or normal FSH with low estradiol: the signal from the brain is low (hypothalamic or pituitary cause).
• Hormonal contraception changes both results.
Good to know
Estradiol levels are not usually needed to adjust menopausal hormone therapy; dosing follows symptoms. Biotin supplements can distort some hormone assays, so pause them before testing if your lab advises.
Key studies and references
Educational content only, written and reviewed by Farhan Tahir, MD. It does not replace individual medical advice. For sudden chest pain, trouble breathing or stroke symptoms, call 911.
AT A GLANCE
Test type
Sex hormones
Also known as
E2, follicle-stimulating hormone
Reviewed by
Farhan Tahir, MD
Questions about your own care?
Dr. Tahir’s team offers consults through Youthful Medicine.
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