Hyaluronic acid

What is hyaluronic acid?

Updated 9 Nov 2026

Short answer

Hyaluronic acid, also called hyaluronan, is a substance the body makes itself. It is found in all connective tissues and organs, including the skin and the fluid in joints.[1] About half of the body's hyaluronic acid is in the skin, where it keeps the tissue moist.[2] Its amount in the skin falls with age.[3]

It is used as a medicine, in cosmetics, in food and as a dietary supplement.[2] Doctors inject it into the knee for osteoarthritis[4] and into folds of the face as a filler.[5] Supplements contain hyaluronic acid made by fermentation or extracted from rooster combs.[6][7]

Sources (7)

  1. Oral Hyaluronan Relieves Wrinkles and Improves Dry Skin: A 12-Week Double-Blinded, Placebo-Controlled Study. Hsu TF, Su ZR, Hsieh YH, Wang MF, Oe M, Matsuoka R, et al. Nutrients, 2021. PMID 34203487
  2. Ingested hyaluronan moisturizes dry skin. Kawada C, Yoshida T, Yoshida H, Matsuoka R, Sakamoto W, Odanaka W, et al. Nutr J, 2014. PMID 25014997
  3. Oral administration of hyaluronic acid to improve skin conditions via a randomized double-blind clinical test. Gao YR, Wang RP, Zhang L, Fan Y, Luan J, Liu Z, et al. Skin Res Technol, 2023. PMID 38009035
  4. Viscosupplementation for osteoarthritis of the knee: a systematic review and meta-analysis. Rutjes AW, Jüni P, da Costa BR, Trelle S, Nüesch E, Reichenbach S Ann Intern Med, 2012. PMID 22868835
  5. Juvéderm injectable gel: a multicenter, double-blind, randomized study of safety and effectiveness. Pinsky MA, Thomas JA, Murphy DK, Walker PS Aesthet Surg J, 2008. PMID 19083502
  6. Oral intake of a new full-spectrum hyaluronan improves skin profilometry and ageing: a randomized, double-blind, placebo-controlled clinical trial. Michelotti A, Cestone E, De Ponti I, Pisati M, Sparta E, Tursi F Eur J Dermatol, 2021. PMID 34933842
  7. Scientific Opinion on Rooster Combs Extract. European Food Safety Authority, 2013. efsa.onlinelibrary.wiley.com

More about hyaluronic acid

Are hyaluronic acid supplements the same as hyaluronic acid injections?Does hyaluronic acid work?How long does hyaluronic acid take to work?Is hyaluronic acid safe?Do hyaluronic acid supplements improve skin?Do hyaluronic acid supplements help knee pain?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.