USP grade nicotine refers to nicotine that meets the standards set by the United States Pharmacopeia (USP), a non-profit organization that sets quality standards for medications, dietary supplements, and other healthcare products in the United States. When a nicotine product is labeled as USP grade, it means that it has been produced, handled, and tested according to strict guidelines to ensure its purity, quality, and safety for use in various applications, including pharmaceuticals, vaping products, and nicotine replacement therapies. Choosing USP grade nicotine provides assurance of its quality and consistency.