Assessment of a Tiger Milk Medicinal Mushroom (Lignosus rhinocerus TM02®)–Based Oral Gel for Pain Reduction and Healing in Minor Aphthous Stomatitis

Recurrent aphthous stomatitis (RAS) is a common oral mucosal condition characterized by painful ulcerations with no consistently effective treatment. Lignosus rhinocerus (tiger milk mushroom) has been traditionally used in Southeast Asia for its wound-healing and anti-inflammatory properties, yet its clinical application for RAS remains insufficiently studied. This double-blind, randomized clinical trial evaluated the efficacy and safety of an oral gel containing L. rhinocerus TM02® (xLr®) extract in adults with minor RAS. Twenty-one participants aged 20 to 50 years were allocated to placebo gel (n = 6), xLr® gel (n = 7), or Kanolone Oral Base Paste (triamcinolone acetonide 0.1%) (n = 5). All gels were applied three times daily for 7 d. Pain intensity was recorded daily using a visual analog scale (VAS), ulcer diameter was measured on days 1, 3, 5, and 7, and epithelialization was assessed using the 3% hydrogen peroxide test. Kanolone produced the greatest reduction in pain (mean VAS: 2.40) and ulcer size (P < 0.05), followed by xLr® (mean VAS: 3.10) and placebo (mean VAS: 3.93). The xLr® group demonstrated faster epithelialization (5.4 ± 0.61 d) compared with placebo (6.8 ± 0.40 d) and Kanolone (6.0 ± 0.63 d), although intergroup differences were insignificant. No adverse events were reported across all groups. These findings suggest that xLr® oral gel is safe and exhibits favorable trends in pain reduction and wound epithelialization, supporting ethnomedicinal claims of L. rhinocerus and indicating the need for larger confirmatory trials.