Keratin
What is it?
Keratin is a very fibrous and tough protein that makes up most of the material contained in the cells forming the epidermis of the skin, hair and nails. A deficiency in this nutrient contributes to hair loss and brittle hair and nails.
What does it do for your skin?
Oral keratin acts as a source of amino acids to keep hair and nails in good condition.
References:
Sant'Anna Addor FA, et al. Clin Cosmet Investig Dermatol. 2018 Sep 10;11:431-436