Skin loses approximately 50% of its hyaluronic acid by age 50; topical and injectable HA can partially restore hydration and volume

This review examined the role of hyaluronic acid (HA) in skin biology and aging. HA is a glycosaminoglycan that can hold up to 1,000 times its weight in water and is a major component of the dermal extracellular matrix. Skin HA content decreases dramatically with age — approximately 50% by age 50 — contributing to dryness, loss of elasticity, and wrinkle formation. The review evaluated topical HA formulations and found that low-molecular-weight HA can penetrate the epidermis and improve hydration, while high-molecular-weight HA forms a protective film on the skin surface.

University of Basel