what is hyaluronic acid

Hyaluronic acid (HA), also called hyaluronan, is a naturally occurring substance broadly distributed throughout connective, epithelial, and neural tissues in the body. It is a large, gel-like molecule classified as a glycosaminoglycan—a type of long, unbranched carbohydrate. HA is unique because it is nonsulfated and synthesized at the plasma membrane. One of its key features is its exceptional ability to bind and retain water—up to around 1,000 times its own weight. This makes it crucial for maintaining hydration, cushioning, and lubrication in tissues. It is found abundantly in the skin where it helps keep the skin hydrated, plump, and youthful by retaining moisture and protecting against wrinkles and dryness. HA also plays significant roles in joints, eyes (found in synovial fluid and vitreous humor), and wound healing. The body produces hyaluronic acid naturally, but levels decline with age, contributing to signs of skin aging such as dryness and loss of elasticity. Medically, HA is used to treat osteoarthritis, dry eyes, and as a cosmetic filler to add volume and reduce wrinkles. It is also used extensively in skincare products for hydration and skin rejuvenation. In summary, hyaluronic acid is a vital moisturizing and cushioning molecule found naturally in the body with broad medical and cosmetic applications based on its hydrating and tissue-protective properties. Its ability to hold vast amounts of water is central to its function in skin health and joint lubrication.