Estriol (Post-menopausal)

Estriol is above the reference range which is likely due to individual variance, supplementation, or exogenous exposure. Increased metabolism from 16-OH-E1 via HSD17β may also be a contributing factor. Estriol is considered a safer estrogen due to its inability to convert back to estrone or estradiol. Elevations may have little clinical significance if other metabolite levels seem appropriate.

The low estriol level may be due to decreased conversion from estrone, estradiol and/or 16-OH-E1. In females, lower estriol levels may be associated with vaginal dryness. Supplementation with estriol is a consideration.

Evaluation of the estrogen metabolism pathway relies on understanding several key steps of metabolism: the amount of unconjugated estrogens, hydroxylation of E1 and E2, methylation of hydroxy estrogens, and the function of key enzymes.

Evaluation of the estrogen metabolism pathway relies on understanding several key steps of metabolism: the amount of unconjugated estrogens, hydroxylation of E1 and E2, methylation of hydroxy estrogens, and the function of key enzymes.