OGX Thick & Full Conditioner benefits thin hair by containing ingredients like Biotin, Collagen, Vitamin B7, and Hydrolyzed Wheat Protein that help to strengthen and volumize the hair strands. These ingredients work to nourish and fortify the hair, making it look thicker and fuller. Additionally, the conditioner is paraben-free and sulfate-free, which can help prevent further damage to thin and delicate hair.