Lactose is a signature disaccharide naturally present in mammalian milk. Its molecule consists of one molecule of D‑glucose linked to one molecule of D‑galactose via a β‑1,4 glycosidic bond. Compared with conventional bovine milk-derived lactose, human milk-derived lactose exhibits molecular configuration, impurity profile and biocompatibility that better match the human physiological system. It is suitable for basic life science research, in vitro cell culture and biopharmaceutical development, serving as a high-quality experimental substrate that recapitulates in vivo physiological conditions.