Estriol (E3)
Specialistalso —
What it isEstriol is the weakest of the three main estrogens and dominates during pregnancy, when the placenta produces it in large amounts.
DoesSupports the pregnant uterus and maternal physiology; used in some HRT formulations for vaginal symptoms.
GoodPregnancy-appropriate levels signal placental health.
BadOutside pregnancy, levels are very low and not typically clinically meaningful.
- Standard
- Pregnancy-specific.
- Optimal
- Not applicable outside pregnancy
How to optimize
- Lifestyle
- —
- Diet
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- Supplements
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- Peptides
- —
- Drugs
- Estriol vaginal preparations for genitourinary syndrome of menopause.
Reference ranges are general adult lab norms; optimal ranges are editorial picks from the longevity literature — not medical advice. Always interpret results with your physician.
within Women's Hormones