Plump up the volume in thin hair with the OGX Thick & Full + Biotin & Collagen Hair Volumizing Shampoo. Ideal for flat to medium volume hair, this thickening shampoo leaves hair feeling fuller and helps create more abundant-looking locks. The nutrient-rich, plump-it-up formula contains vitamin B7 biotin, which helps strengthen hair to maintain growth, and collagen, a building block for healthy hair. The luscious blend in this thickening shampoo also contains hydrolyzed wheat proteins for hair th