Study aim: To investigate the effect of syrup containing marshmallow and purslane extracts on improving symptoms of dry mouth, including oral moisture, mucus stickiness, saliva secretion, and swallowing and speech disorders. Design: A triple-blind, parallel-group, randomized, phase 3 clinical trial on 60 patients. Randomization will be performed using a simple method and sequential allocation. Settings and conduct: Zahedan Dental School. Participants will be selected from patients with dry mouth. The syrups are coded in identical bottles and are similar in appearance, taste, smell, and consistency. Symptoms of dry mouth will be assessed and recorded before the start of the intervention and in the second and fourth weeks. Data will be collected using a standardized questionnaire and clinical examinations. Participants/Inclusion and exclusion criteria: Inclusion criteria: Diagnosis of dry mouth based on a standard questionnaire (positive response to at least three questions). Objective dry mouth index above 30. No tobacco, alcohol, or drug use. Not pregnant or breastfeeding. No history of chemotherapy or radiotherapy in the past six months. No use of corticosteroids or drugs that affect saliva secretion. Inclusion criteria: Unwillingness to participate in the study or failure to complete the informed consent form. Intervention groups: Intervention group: They receive syrup containing marshmallow and purslane extract. The syrup is prescribed as directed for 4 weeks, three times a day, one spoonful at a time. Control group: They receive syrup with the same appearance, consistency, taste, and smell as the intervention syrup, but without the active ingredient, in the same manner as the intervention group. Main outcome variables: Moisture of the oral mucosa; amount of saliva secretion; reduction of adhesion of the mucosa to the teeth; improvement of swallowing disorders; improvement of speech disorders.