HEPES, which stands for Hydroxyethylpiperazine Ethane Sulfonic Acid, is a type of organic buffering agent that plays a crucial role in cosmetic solutions. Its pH level of 7.0-7.6 makes it relatively neutral-basic, which helps balance out the acidic components in the cosmetic formula. This chemical molecule is often combined with glycolic acid to maintain pH conditions during chemical reactions. HEPES and glycolic acid combo is commonly used in skincare products, a low levels, to extend their shelf life and preserve their quality.