2026-01-132026-01-132025SANTOS, Rodrigo Wilmes dos et al. Effects of L-glutamine and hyaluronic acid associated with photobiomodulation on oral mucositis: a randomized clinical trial. Supportive Care in Cancer, Berlin, v. 33, n. 5, e430, 2025. DOI: 10.1007/s00520-025-09480-z. Disponível em: https://link.springer.com/article/10.1007/s00520-025-09480-z. Acesso em: 8 jan. 2026.0941-4355e- 1433-7339https://link.springer.com/article/10.1007/s00520-025-09480-zObjective To investigate whether the application of L-glutamine (L-G) and hyaluronic acid (HA) associated with photobiomodulation (PBM) and the Preventive Oral Care Protocol (POCP) would present similar efficacy as the exclusive use of PBM, associated with POCP, in the prevention and control of severe oral mucositis (OM). Study design Patients with head and neck cancer undergoing radiochemotherapy (RCT) were randomized into two groups: group A, patients that received PBM+POCP (n=24), and group B, patients that received PBM+POCP+L-G+HA (n=24). OM was assessed using the National Cancer Institute (NCI) and World Health Organization (WHO) scales. The impact of oral health on patients’ quality of life and perception of OM symptoms was evaluated. Assessments were made at the 1st, 7th, 14th, 21st, and 30th radiotherapy (RT) sessions. Results When the severity of OM was assessed according to the WHO scale in the 30th RT, group B showed lower rates of severe OM than group A. There were no differences when using the NCI scale. The impact of oral health on quality of life and the symptoms reported by patients were lower in group B at all times evaluated. Conclusion The combination of PBM+POCP+L-G+HA resulted in a significantly lower severity of OM than PBM+POCP alone, according to the WHO scale at the 30th RT. Trial registration Brazilian Clinical Trials Registry—REBEC no. RBR-6ybmgcv. Registration March 27, 2022.engAcesso RestritoOral mucositisGlutamineHyaluronic acidPhotobiomodulation therapyRadiotherapyHead and neck cancerArtigo10.1007/s00520-025-09480-z