Transform fine, flat strands into fabulously fuller hair with HASK's Biotin Boost Thickening Shampoo. This shampoo works on three levels to help deliver volume - featuring biotin to help hair look thicker, collagen to fortify locks, and coffee to help boost strands. Go big or go home! Free of sulfates, parabens! Hask® Biotin Boost Thickening Conditioner. Made with biotin, collagen & coffee. This conditioner helps promote thicker-looking hair with biotin for volume, collagen for strength, and coffee to help boost strands. Gently detangles to leave hair feeling soft and manageable. This product is free of sulfates, parabens, phthalates, gluten, drying alcohol and artificial colors.