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Part of the skin and hair peptide hub: every topical and cosmetic peptide we cover, with its evidence grade.

Evidence: HighNot a peptideFDA ApprovedNot a peptideFDA-approved as devicesFillers and joint injections

Hyaluronic Acid

A sugar chain, not a peptide, found throughout the body and sold as dermal fillers, joint injections and supplements

Hyaluronic acid is a long chain of repeating sugar units that holds water in skin, joints and the eye. It is not a peptide. In the US its injectable forms are approved as medical devices, not drugs: fillers such as Juvéderm and joint injections such as Synvisc. Its evidence ranges from collagen biopsies to an oral supplement trial.

At a Glance Read Research →
Overview

What is it?

Hyaluronic acid is a glycosaminoglycan, an unbranched chain of two alternating sugars, and it is almost everywhere in vertebrates. It binds large amounts of water, which is why it fills space in skin and cushions joints. Since its isolation in 1934 it has been studied as a drug carrier and as a treatment in eyes, joints, airways and aesthetic medicine. It appears in this encyclopedia because it is sold alongside peptides, not because it is one.

The FDA regulates its injectable products as devices through premarket approval: Synvisc for knee osteoarthritis and Juvéderm as a dermal implant, among many others. That route judges a product's safety and effectiveness for its labelled use, and it means each brand is its own approval.

Fillers do more than occupy space. In 11 older volunteers, cross-linked hyaluronic acid injected into sun-damaged forearm skin increased new collagen around the filler at 4 and 13 weeks against saline, with fibroblasts that looked mechanically stretched. That may explain why fillers last longer than the gel alone would.

The oral and joint evidence is thinner. A trial in 129 women found an oral supplement improved skin hydration within weeks. In partial rotator cuff tears, sodium hyaluronate was injected with and without platelet-rich plasma, and the two groups given the plasma showed significantly higher shoulder-function scores after treatment.

1934
First isolated
studied ever since
Devices
How the FDA approves it
fillers and joint injections
4 and 13 wk
New collagen around filler
forearm biopsies
Structured data

At a Glance

Every value in this table is printed from the Grey Peptides dataset, the same record the compound explorer and comparison tool read, so the three can never disagree.

ClassNote: Hyaluronic acid is a glycosaminoglycan polymer (repeating disaccharides of D-glucuronic acid and N-acetyl-D-glucosamine), not a peptide. It is included here because injectable HA is a mainstay of the same aesthetic and regenerative-medicine market as peptide therapeutics.
SequenceNot applicable — HA is a linear polymer of repeating [D-glucuronic acid (β1→3) N-acetyl-D-glucosamine (β1→4)] disaccharides.
Formula(C14H21NO11)n
Half-lifeno single figure: it depends on cross-linking and where it is injected
Typical dosedermal injection, intra-articular injection, or topical
US statusFDA Approved
Evidence levelHigh
Last reviewed2026-10-16
Evidence

Published Research

These are the studies of hyaluronic acid as a product given to people, read from their PubMed abstracts: filler and skin-booster trials, injections for joints, oral use, and reviews of the complications. The far larger literature on the body's own hyaluronan, and on materials built from it, is outside this entry.

Human2007

Fillers make new collagen

11 volunteers with sun-damaged forearm skin, mean age 74, received cross-linked hyaluronic acid and saline. Biopsies at 4 and 13 weeks showed more collagen and procollagen around the filler, and up-regulated collagen genes, against saline.

PMID: 17309996
Human2023

Taken by mouth

129 women of different ages and skin types took oral hyaluronic acid or placebo. Skin hydration improved within 2 to 8 weeks, tone within 4 to 8 weeks, and epidermal thickness by 12 weeks.

PMID: 38009035
Human2019

In the shoulder

In partial rotator cuff tears, PRP and hyaluronate plus PRP improved shoulder scores and shrank tears on MRI; the combination did best at 12 months, and hyaluronate alone was not superior.

PMID: 30199423
Review2018

What it is

A review of hyaluronic acid's history since 1934, its structure as a chain of N-acetylglucosamine and glucuronic acid, how the body makes and breaks it down, and its uses from eye surgery to cosmetics.

PMID: 30960626
Human2026

Lip filler against an FDA-approved comparator

In an evaluator-blind trial randomising patients 3:1 to Belotero Intense with lidocaine or Restylane Silk with lidocaine, 91.1% (144 of 158) responded on lip fullness at week 8, the filler met its non-inferiority margin, about half of responders kept the improvement to week 48 in a post hoc analysis, and there were no severe or serious related adverse events.

PMID: 42875033
Human2026

Nasolabial folds: 324 adults

In a multicentre evaluator-blinded trial in 324 Chinese adults, a cross-linked hyaluronic acid gel premixed with lidocaine was non-inferior to an established filler for correcting nasolabial folds at six months (88.3% against 85.2% improving by at least one grade), with similar adverse events, mostly induration and swelling.

PMID: 42501253
Human2026

Skin booster by mesotherapy

In a multicentre randomised controlled study, a sodium hyaluronate composite solution delivered by mesotherapy improved signs of facial skin ageing with a favourable safety profile.

PMID: 42367716
Human2026

Knee osteoarthritis: one 2% injection or five 1%

Pooling two trials, one 2% sodium hyaluronate knee injection reduced pain over 12 months about as much as five 1% injections (37.7% against 33.6% relative reduction), meeting a non-inferiority margin, though more patients in the 1% group reached a clinically important improvement. An exploratory cross-trial analysis by authors from the manufacturers.

PMID: 42739578
Review2026

Fillers or fat around the eyes

A systematic review comparing hyaluronic acid fillers with fat grafting for restoring volume around the eyes concludes that its indirect comparison only generates hypotheses, and that direct trials with standard complication definitions and longer follow-up are needed.

PMID: 42860631
Review2026

Filler complications, from bruising to blindness

A 2026 practical guide gathers the evidence on recognising, preventing and managing hyaluronic acid filler complications across their full range, from bruising to vascular events that can cause blindness.

PMID: 42853707
Safety

Side Effects & Contraindications

Reported Side Effects

Depends on the product and where it is injected.

● Swelling, bruising and tenderness at injection sites
● Filler complications, including lumps and, rarely, injection into a blood vessel
● Joint injections can cause temporary pain and swelling
● Oral supplements were well tolerated in the trial above

Contraindications & Cautions

Set by each device's labelling.

● Injection by untrained practitioners, the main source of filler harm
● Known allergy to a product's components
● Tested athletes — see the Sport (WADA) row below
Questions

Frequently Asked Questions

?Is hyaluronic acid a peptide?

No. It is a chain of sugars, a glycosaminoglycan. It appears here because it is sold alongside peptides.

?Is it FDA-approved?

Its injectable products are approved as medical devices, brand by brand, such as Synvisc for knees and Juvéderm for the face.

?Do fillers just fill space?

Not only. Biopsies in older volunteers showed new collagen forming around injected filler for at least 13 weeks.

?Does it work as a supplement?

One trial in 129 women found better skin hydration within weeks. The evidence for oral use is far thinner than for injections.

Bibliography

References

  1. [pubmed] Wang F, et al. "In vivo stimulation of de novo collagen production caused by cross-linked hyaluronic acid dermal filler injections in photodamaged human skin." Arch Dermatol, 2007;143(2):155-63. PMID: 17309996.
  2. [pubmed] Gao YR, et al. "Oral administration of hyaluronic acid to improve skin conditions via a randomized double-blind clinical test." Skin Res Technol, 2023;29(11):e13531. PMID: 38009035.
  3. [pubmed] Cai YU, et al. "Sodium Hyaluronate and Platelet-Rich Plasma for Partial-Thickness Rotator Cuff Tears." Med Sci Sports Exerc, 2019;51(2):227-233. PMID: 30199423.
  4. [pubmed] Fallacara A, et al. "Hyaluronic Acid in the Third Millennium." Polymers (Basel), 2018;10(7). PMID: 30960626.
  5. [pubmed] Bellamy N, et al. "Viscosupplementation for the treatment of osteoarthritis of the knee." Cochrane Database Syst Rev, 2006;2006(2):CD005321. PMID: 16625635.
  6. [pubmed] Wongprasert P, et al. "Evaluating hyaluronic acid dermal fillers: A critique of current characterization methods." Dermatol Ther, 2022;35(6):e15453. PMID: 35293660.
  7. [other] US FDA, premarket approval database (openFDA device records): SYNVISC, P940015, Sanofi Genzyme, intra-articular hyaluronic acid; JUVEDERM, P050047, Allergan, dermal implant. Read September 30, 2026.
  8. [pubmed] Moradi A, et al. "A Prospective, Multicenter, Evaluator-Blind, Randomized, Comparator-Controlled Study of Belotero Intense (+), a Hyaluronic Acid Filler With Lidocaine, for Lip Augmentation." Aesthet Surg J, 2026;46(11):1236-1245. PMID: 42875033.
  9. [pubmed] Huang X, et al. "Prospective Evaluation of Cross-linked Sodium Hyaluronate Gel for Injection in Treating Moderate-to-Severe Nasolabial Folds: A Randomized Controlled Evaluator-Blind Non-inferiority Study." Dermatol Ther (Heidelb), 2026;16(9):4539-4549. PMID: 42501253.
  10. [pubmed] Yang R, et al. "Efficacy and Safety of a Novel Sodium Hyaluronate Composite Solution via Mesotherapy for Facial Rejuvenation: A Multicenter Randomized Controlled Study." Plast Reconstr Surg Glob Open, 2026;14(6):e7853. PMID: 42367716.
  11. [pubmed] Costa F, et al. "Exploratory Cross-Trial Non-Inferiority Analysis of 2% Versus 1% Sodium Hyaluronate in Knee Osteoarthritis." J Clin Med, 2026;15(17). PMID: 42739578.
  12. [pubmed] Sekhon S, et al. "Hyaluronic acid fillers and autologous fat grafting for periocular volume restoration: a systematic review and indirect comparison." Orbit, 2026:1-11. PMID: 42860631.
  13. [pubmed] Kamrani P, et al. "From Bruising to Blindness: A Practical Guide to Identifying and Managing Hyaluronic Acid Filler Complications." Dermatol Surg, 2026. PMID: 42853707.

Sources & Citations

Studies were read from PubMed; device approvals come from openFDA, read September 30, 2026.

Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Consult a licensed healthcare provider before making health decisions.

Last reviewed: 2026-10-16