USP nicotine is nicotine that meets the quality standards set by the United States Pharmacopeia (USP), a recognized authority that establishes criteria for the quality, purity, and potency of medications, supplements, and related substances in the United States. This designation indicates that the nicotine has been produced, handled, and tested according to strict guidelines to ensure its safety and effectiveness for various applications, including pharmaceuticals, nicotine replacement therapies, and vaping products. In essence, USP nicotine is certified to meet rigorous standards of quality and purity set by the USP.