Bio Coat Concentrated Biotin Supplement - 16 oz BioCoat is a concentrated biotin supplement in a tasty powder. Biotin is one of the essential B vitamins that works as a nutritional enzyme for the synthesis of fatty acids, important building blocks for skin and coats. It is helpful and effective for dry skin, constant scratching, dull or thin coats, and excessive shedding. BioCoat contains also primary dried yeast which differs from brewers' yeast. Primary dried yeast is far more nutritious and not simply a by-product of the brewing industry.