Hong Kong’s Consumer Council has issued a warning about the potential health risks associated with certain mouth ulcer ointments and gels after testing ten popular products priced between HK$29.9 and HK$79.5.
While these topical products are marketed to relieve pain, speed up healing, and reduce inflammation from mouth ulcers, the Council found that improper use may irritate the oral mucosa and trigger allergic reactions.
Two products—EUROCORT and Oramedy pastes—were found to contain the prescription-only steroid triamcinolone acetonide, a medium-potency topical corticosteroid that should only be used under medical supervision.
Dick Sung Ming-tat, president of the Pharmaceutical Society of Hong Kong, cautioned that long-term or inappropriate use of this steroid can suppress the immune system and lead to serious side effects.
He advised pregnant women, breastfeeding mothers, hepatitis patients, and those on immunosuppressants to avoid these products entirely. Children under 12 require different dosing and must follow the doctor’s instructions.
Choline salicylate, a salicylate compound, was detected in Bonjela Fast-Acting Gel and Dermojela Gel.
Sung warned that salicylates carry a risk of Reye’s syndrome in children and adolescents under 16 and should be avoided by pregnant or breastfeeding women, people with liver or kidney problems, and those with bleeding disorders.
Combining these gels with other salicylate-containing medicines, such as aspirin, may cause overdose and adverse reactions.
The Council also reminded consumers to watch for SanteCare’s Oralmedic Mouth Ulcer Gel and SanteCare’s Oralmedic Kids Mouth Ulcer; the former is not for sulfur allergies, and the latter was found to contain potential fragrance allergens such as linalool and limonene.
Bonjela fast-acting gel for mouth ulcers also contains menthol. Sung noted that menthol could offer a cooling sensation for pain relief and mask the medication’s bitter taste.
However, high doses of menthol may cause hemolytic reactions in people with G6PD deficiency (favism).
In addition, EUROCORT paste and STADA Kamistad-Gel N include the anesthetic lidocaine for pain relief. Although effective for temporary relief, lidocaine offers no anti-inflammatory or healing benefits.
Overuse does not improve recovery and may increase the risk of systemic side effects, including taste disturbances or nausea.
As a Part 1 poison in Hong Kong, lidocaine products must be sold under pharmacist supervision. Patients with severe arrhythmia, chronic liver/kidney disease, or lidocaine allergy were advised to avoid them.
The Council noted that online promotions recently have heavily marketed Japanese, South Korean, and Thai mouth ulcer products as “miracle” natural remedies.
However, a September 2025 test of Japanese patches and ointments revealed that two contained triamcinolone acetonide—a Part 1 poison in Hong Kong requiring a prescription.
Many of these imported products only provide ingredient and usage information in Japanese, making it difficult for local consumers to identify restricted substances.
The Council reminded the public that possessing unregistered pharmaceuticals or Part 1 poisons is illegal and may result in prosecution.
Consumers are strongly urged to carefully check ingredient lists, consult healthcare professionals before use—especially when steroids, salicylates, or anesthetics are involved—and avoid self-medicating with imported products of uncertain composition.
