Study aim: Comparison of the incidence of oral mucositis among the three study groups. Comparison of the severity of oral mucositis among the three study groups. Design: The study is designed as a Phase II, randomized, double-blind, controlled trial with a parallel-group design involving 63 participants (21 participants per group). Randomization and Allocation:To ensure equal distribution among the three arms, balanced block randomization with a block size of three will be employed. The randomization sequence will be produced via Random Allocation Software. Settings and conduct: TheConducted at Sadaf Clinic (Imam Khomeini Hospital Complex), this study employs a blinded design. Randomization and allocation will be managed by a non-clinical third party to prevent bias. Clinicians and assessors will be blinded to treatments, which are visually identical. Participants will rinse thrice daily for one minute (expectorating thereafter). Assessments start one week post-radiotherapy, with follow-ups lasting one to two months. All adverse effects will be monitored across all groups Participants/Inclusion and exclusion criteria: :Patients undergoing head and neck radiotherapy due to cancer. The radiotherapy regimen consists of 30 sessions with a total dose of 75 Gy. Exclusion Criteria:Patients with systemic diseases causing oral ulceration or mucositis. Pregnant women. Patients undergoing concurrent chemoradiotherapy. Intervention groups: The particieThe three study arms consist of: (1) Control: standard care (normal saline, Nystatin, and dietary advice); (2) Silymarin: a prepared mouthwash using Gol Daru tablets dissolved in water; and (3) Hanisol: Hanisol syrup (Manitasa) used as a mouthwash. All interventions require a one-minute rinse three times daily, followed by expectoration Main outcome variables: The incidence and severity of oral mucositis will be compared among the three study groups