Image 1 of 1 Pro Bi-Est + Quicksilver Scientific $40.00 Nanoemulsified topical serum using estriol and estradiol derived from phytosterols, natural compounds used to synthesize bioidentical estrogens. Quantity: Add To Cart Added! Nanoemulsified topical serum using estriol and estradiol derived from phytosterols, natural compounds used to synthesize bioidentical estrogens.