Estriol is one of three estrogen hormones. Estriol levels rise throughout pregnancy, helping to keep your uterus and unborn baby healthy. The levels are at their highest right before childbirth. They help prepare your body for labor and delivery.

Everyone makes estriol. But in people who aren't pregnant, the levels are almost undetectable. Other names for estriol include oestriol and E3.

3. Product Benefits

During pregnancy, estriol:

• Helps your uterus grow as the fetus gets bigger.
• Makes your body more sensitive to other pregnancy hormones.
• Prepares your body for labor and delivery and breastfeeding.

4. Product Side Effects

Estriol is the weakest of the three estrogen types. It's less likely to cause side effects like high blood pressure and blood clots than estradiol, the strongest estrogen.

Potential side effects of estriol include:

• Abnormal menstruation.
• Bloated stomach.
• Breast pain (mastalgia).
• Darkening of the skin.
• Hair loss.
• Headaches.
• Nausea and vomiting.
• Painful menstrual cramps (dysmenorrhea).
• Vaginal itching or yeast infections.
• Weight gain.