Chios mastic is a natural product with strong antimicrobial, anti-inflammatory and antioxidant properties, and well-established benefits for dyspeptic disorders. The aim of the present study is to investigate the effectiveness of a natural aqueous extract of Chios mastic (mastic water), a by-product of Chios mastic processing, in the management of dyspepsia. This will be a 3-month randomized double-blind controlled clinical trial in adults with dyspepsia. Participants will be blindly randomized to an intervention group, which will receive 600 mL/d of a carbonated beverage enriched with Chios mastic water (0.2%), or a control group, which will receive 600 mL/d of an identical placebo beverage with no active ingredients. Participants will be evaluated in terms of anthropometric indices, lifestyle habits, severity of dyspepsia-related gastrointestinal symptoms, quality of life, as well as biochemical markers, both pre- and post-intervention.