"Best Leave-In Conditioner on the market!" Says B. The Product customer Candace Powell for our moisturizing Leave-In Conditioner, the Leave It In. Read real results on thin hair that easily tangles. Does your hair break easily? Our Leave It In, paired with our Biotin shampoo and conditioner is the perfect remedy for thin hair that breaks easily. Spend $50 @btheproduct.comand receive a free travel size Biotin shampoo and conditioner.