Bi-Est+ Topical Replenishing Serum is a nanoemulsified topical serum providing 1 mg of bioidentical estriol (E3) and 0.25 mg of bioidentical estradiol (E2) per 2 pump dose. The estriol and estradiol are derived from phytosterols, natural compounds used to synthesize bioidentical estrogens. Bi-EST+ is delivered using proprietary lipid nanoemulsion technology for enhanced absorption of ingredients.*