USP nicotine refers to nicotine that meets the standards set by the United States Pharmacopeia (USP), a compendium of quality standards for pharmaceutical substances and products. This designation signifies that the nicotine has been produced, processed, and handled according to strict guidelines to ensure consistency, purity, and safety. USP nicotine is commonly used in pharmaceuticals, nicotine replacement therapies (NRTs), and other medical applications where high-quality nicotine is required. Adhering to USP standards ensures that the nicotine meets stringent quality criteria, providing assurance of its purity and suitability for use in medical products.