Estriol (E3) Saliva Test (s)
The weakest, most benign of the three types of estrogen produced by the body.
Estriol is the weakest of the three major naturally-occurring estrogens in women. It is a product of the metabolism of estrone and estradiol and is excreted in the urine in greater amounts than estradiol. Because of its weak estrogenic activity, estriol is sometimes preferred for intravaginal use as an alternative to systemic estrogen therapy for the treatment of urogenital atrophy in postmenopausal women. It is also used in anti-aging skin creams as a form of topical estrogen replacement to counteract the effects of age-related estrogen loss on skin. Estriol is the major estrogen found in the maternal circulation during pregnancy; 90% of this circulating estriol is the product of metabolism of DHEA from the fetal adrenals, and so maternal estriol levels are used as an indicator of fetal health. In non-pregnant women, estriol levels are similar in both pre– and post-menopause, and are also similar to levels in men. The saliva test for estriol has been found to be predictive of increased risk of preterm labor in pregnant women. In non-pregnant women it is most commonly used for monitoring of levels in women using estriolcontaining supplements as part of hormone replacement therapy. The reference range for saliva estriol is <3.0 pg/mL in premenopausal women during the luteal phase; <1.9 pg/mL in postmenopausal women; and <1.7 pg/mL in men.