Hyaluronic acid

Also known as sodium hyaluronate, hyaluronan, HA.

Last reviewed October 9, 2026 · Jump to references

What is Hyaluronic acid?

In plain words

Hyaluronic acid is a long-chain sugar found naturally in skin, joints, and eyes. It holds water and helps tissues stay moist and slippery, while the body continually breaks it down and replaces it. Researchers study it for skin hydration, joint symptoms, dry eyes, and wound healing. Evidence and risks differ between products, so findings about an injection do not necessarily apply to a pill or cream.

Technical definition

Hyaluronic acid (hyaluronan; sodium hyaluronate is its sodium salt) is a naturally occurring, nonsulfated glycosaminoglycan composed of repeating D-glucuronic acid and N-acetyl-D-glucosamine units in the extracellular matrix. It binds water to support tissue hydration and lubrication and interacts with receptors such as CD44 and RHAMM to influence cell adhesion, migration, and signaling. Regulatory status depends on formulation and intended use: certain injectable and ophthalmic products have FDA approval, while dietary supplements are not FDA-approved treatments.

Educational information only. This page does not provide medical advice or determine whether a supplement is appropriate for you. Review supplements with a qualified healthcare professional, especially if you take medication, are pregnant, have surgery scheduled, or have a chronic medical condition.

Evidence by use

Each use is rated on its own. There is no single overall effectiveness score.