Hyaluronic acid is an acidic mucopolysaccharide macromolecular substance widely found in connective tissues of humans and animals, which has important functions such as maintaining moisture, regulating osmotic pressure, maintaining tissue morphology, and lubricating, diffusing barriers and buffering stresses. The hyaluronic acids in the human body will gradually be lost from age 25 years old, only 65% left at the age of 30 and 25% at 50. The hyaluronic acids lost through aging, leading to the skin gradually losing its elasticity and luster, accompanying with aging, wrinkles and slacking. Efficacies of different molecular weight ranges High molecular weight sodium hyaluronate 1.6 million Da Form a dense moisturizing bio-form on the skin surface for long-term moisturizing and anti-PM 2.5. Moderate molecular weight sodium hyaluronate 0.2-1.6 million Da Better moisturizing and lubricating, slow release and stable emulsification. Low molecular weight sodium hyaluronate 10,000 Da -0.2 million Da Repair damages and skin just beginning to age: hydrate and soften the stratum comeum for long-lasting moisturizing and tender skin; increase skin elasticity and defer skin aging; promote the proliferation and differentiation of epidermal cells, scavenge oxygen free radicals. Oligo sodium hyaluronate 10,000Da Transdermal absorption and deep moisturizing. Anti-aging and repair after sunburn. Sodium hyaluronate, which has the same high hygroscopicity whether in low humidity or high humidity conditions, automatically regulates and maintains skin moisture, and is known as the Key to the fountain of youth. Therefore, it is widely used in cosmetics as an ideal natural moisturizer to manufacture products suitable for different skin types and used in different climates and environments. High molecular weight sodium hyaluronate can form a breathable thin film on the skin surface to help the skin lock in moisture and block the invasion of foreign bacteria, dust and ultraviolet rays to protect the skin from harm. Low molecular weight sodium hyaluronate can rapidly penetrate into the dermis to slightly expand the capillaries, promote blood circulation, improve metabolism and to promote the nutrient absorption by the skin cells with the functions of removing wrinkles, enhancing skin elasticity and deferring skin aging.