Hyaluronic acid

Does the molecular weight of hyaluronic acid matter?

Updated 9 Nov 2026

Short answer

For supplements, it is not clear. In one trial in 61 people with dry skin, hyaluronic acid of 300 kDa and of 800 kDa both raised skin moisture.[1] In creams, only the smaller forms reduced wrinkle depth.[2]

What molecular weight means

Hyaluronic acid molecules come in different sizes. The size is given as molecular weight, in kilodaltons (kDa) or megadaltons (MDa, 1,000 kDa). Trials have used forms from 50 kDa to 1.8 MDa.[2][3]

Supplements

  • 61 people with dry skin took 120 mg a day of hyaluronic acid of 800 kDa or 300 kDa, or a placebo, for 6 weeks. Both forms raised skin moisture more than placebo. The 300 kDa group still had better moisture than the placebo group 2 weeks after they stopped.[1] In a questionnaire, both groups rated their facial skin better than the placebo group did, and dermatologists found no side effects linked to either form.[1]
  • A trial in 150 adults used sodium hyaluronate of 1.8 MDa, at 60 or 120 mg a day. It found better hydration and elasticity after 12 weeks. The 120 mg dose had larger effects than the 60 mg dose.[3]
  • A trial in 60 women used a mix of many molecular weights at 200 mg a day. It found better hydration and less wrinkle depth after 28 days.[4]

In mice, gut bacteria were needed to absorb hyaluronic acid. They cut it into pieces smaller than 3 kDa before absorption. Pieces that were not absorbed were turned into short-chain fatty acids.[5]

Creams

76 women aged 30 to 60 applied a cream with 0.1% hyaluronic acid of 50, 130, 300, 800 or 2,000 kDa around one eye twice a day for 60 days. Around the other eye, they applied a cream without it, so each woman was her own control. Skin hydration and elasticity were measured before the start and after 30 and 60 days.[2]

  • All the creams improved skin hydration and elasticity.[2]
  • Only the 50 kDa and 130 kDa creams reduced wrinkle depth. The authors think small forms get into the skin better.[2]

Injections

Some injections use a different form. Of 89 knee injection trials in a 2012 review, 22 used cross-linked hyaluronic acid.[6] The face filler Juvéderm also uses cross-linked hyaluronic acid.[7]

What is still unknown

PubMed searches for this page found only one trial that compared two sizes of hyaluronic acid taken by mouth, and it lasted 6 weeks.[1] The other trials differed in dose (60 to 200 mg a day), in length (4 to 12 weeks) and in the people they studied, so their results cannot be compared directly.[3][4]

Sources (7)

  1. Ingestion of hyaluronans (molecular weights 800 k and 300 k) improves dry skin conditions: a randomized, double blind, controlled study. Kawada C, Yoshida T, Yoshida H, Sakamoto W, Odanaka W, Sato T, et al. J Clin Biochem Nutr, 2015. PMID 25834304
  2. Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. Pavicic T, Gauglitz GG, Lersch P, Schwach-Abdellaoui K, Malle B, Korting HC, et al. J Drugs Dermatol, 2011. PMID 22052267
  3. Oral sodium hyaluronate improves skin hydration, barrier function and signs of aging: a randomized, double-blind, placebo-controlled trial in 150 healthy adults. Dolečková I, Kušnierik P, Berka V, Šimek M, Matějková I, Prokopec F, et al. Sci Rep, 2025. PMID 41422283
  4. 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
  5. Molecular weight and gut microbiota determine the bioavailability of orally administered hyaluronic acid. Šimek M, Turková K, Schwarzer M, Nešporová K, Kubala L, Hermannová M, et al. Carbohydr Polym, 2023. PMID 37182970
  6. 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
  7. 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

More about hyaluronic acid

What is 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?

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