Our Estrogen Oil Contains Natural Estriol (one of the 3 main Estrogen’s) in a 2 ounce bottle. We offer Estriol in an essential oil base so it does not interfere with the delicate PH balance in the vaginal tract. When used as directed for vaginal dryness. Estriol has been reported provide great relief. The blend of natural oils is designed to moisturize the tissue of the vagina and deliver the Estriol directly where it is most needed. We strongly encourage the use of Progesterone whenever you use any form of Estrogen. Please read the information on progesterone and its balancing effects on our site. The natural estrogen, estriol USP, is made the same way natural progesterone USP is made. Sterol analogues found in many varieties of plants are combined with specific bacteria and the resulting hormone is bio identical in chemical structure to the hormone produced by the human body. Since 1999, radiant laboratories have been a leader in transdermal delivery using the highest quality, cleanest base available today. Our USP Grade Progesterone is made from Wild Yam. It is Bio-identical to What Is Produced in the Human Body. Safe and Effective Bio-identical Hormone Replacement Therapy - Very Effective on Menopausal Symptoms.