Hyaluronic Acid Gels for Canker Sores: What Improved?

Did the gel help immediately?

In a 2006 trial¹ enrolling 120 adults, both 0.2% hyaluronic-acid gel and its matching placebo reduced soreness after application. Relief lasted about 30 minutes. Across the following seven days, soreness did not differ significantly between treatments.¹

The authors suggested that coating the ulcer could explain the immediate comfort. That was a proposed explanation, not a demonstrated healing mechanism. Fewer ulcers on one day and fewer new ulcers on another did not establish a consistent benefit throughout the week. The investigators acknowledged that the study was too short to measure ulcer duration accurately.¹

Did a later trial find better pain relief?

A 2022 trial² randomized 70 people aged 11 to 50 to 0.2% sodium hyaluronate with 12% of the polymer PVP, or matching gel without hyaluronate. Fifteen were excluded from analysis, having used additional treatment or exhausted their gel early.²

Pain ratings favored hyaluronate from days three to seven: day-three means were 4.00 versus 5.14 out of ten. Both groups received PVP; the comparison tested added hyaluronate.²

ISDIN funded the study and supplied the gels. Its ulcer-size table reports a significant difference, but its discussion says size reduction was not significant. This contradiction weakens faster-healing claims.²

Does the newer herbal-gel study settle the question?

A 2026 paper³ included 99 children aged seven to 12 with recurrent aphthous ulcers. It compared placebo, 0.2% hyaluronic acid alone, and a blend containing hyaluronic acid, Aloe vera, Myrtus communis and Populus euphratica extracts.³

By day seven, 79% receiving the blend versus 42% receiving placebo had healed. That is a result for the blend, in children. It cannot establish the same effect for a plain gel used by an adult.³

The paper’s text and table assign one healing-rate comparison differently, adding uncertainty about the hyaluronic-acid-only result. Ulcer recurrence over 30 days did not differ significantly between groups.³

What should you check before buying another tube?

Photograph the ingredient list and ask a pharmacist or dentist which formulation and outcome support the claim: less pain after application, lower pain over several days, or earlier ulcer closure. These trials give different answers to those questions.¹²³

Most mouth ulcers settle within a week or two. NHS⁴ advice includes softer foods and avoiding spicy or acidic food while the ulcer is sore. See a dentist or GP if an ulcer lasts more than three weeks, differs from your usual ulcers, bleeds, or becomes more painful and red. Temporary comfort should not postpone that assessment.⁴

The “Patches That Need a Look” section of Is It My Breath? explains the three-week check and how recording the first date helps you give the dentist a useful history.