Glycylglycine is a natural dipeptide composed of two glycine molecules linked by a peptide bond. It is one of the key small peptides that help stabilize protein structures and maintain cellular hydration. As a valuable bioactive compound with increasing research attention, glycylglycine is regarded as a "moisturizing and anti-aging agent" in dermatology and cosmetic science. Modern research has confirmed that it possesses various biological activities, including hydration maintenance, antioxidant protection, skin barrier support, collagen synthesis promotion, and anti-aging properties.