Estriol is one of the three primary estrogens produced in the human body, alongside estradiol and estrone. The form used in this formulation is synthesized from plant sources and is bioidentical, meaning it is structurally identical to the estriol naturally produced in the body. Estriol has been studied in the context of hormone balance and menopausal health. This ingredient can be compounded into various dosage forms, including capsules, creams, troches, and suppositories, with strengths tailored to meet individual needs.