The Supersaturated Hydrogen-Rich Water for Outpatients with Persistent Excess Weight (HOPE) study is a Phase III, multicenter, randomized, double-blind, placebo-controlled study designed to evaluate the efficacy and safety of daily consumption of supersaturated hydrogen-rich water in adults with persistent excess body weight. The trial investigates whether sustained exposure to molecular hydrogen can favorably influence body composition and key metabolic outcomes compared with a placebo water lacking dissolved hydrogen. By enrolling outpatients across multiple centers and applying rigorous blinding and randomization procedures, HOPE aims to generate high-quality clinical evidence on the potential role of hydrogen-rich water as a non-pharmacological, adjunctive strategy for weight management and metabolic health.

Inclusion Criteria:

• Age > 18 years
• Body mass index > 25.0 kg/m2 (persisted for at least six months before screening)
• Stable on their therapy (if any) for ≥ 3 months
• Free of acute disorders and severe chronic diseases
• Informed consent signed
• Normal fasting breath hydrogen levels < 15 ppm

Exclusion Criteria:

• History of dietary supplement use 4 weeks before the study commences
• Abnormal values for lab clinical chemistry not related with stiyd outcomes (> 2 SD)
• No consent to randomization
• Unwillingness to return for follow-up analysis
• Participation in other clinical trials
• Participants starting or changing major treatments during the study period

Data obtained through this study may be provided to qualified researchers with academic interest in obesity/overweight. Data will be coded, with no PHI included. Approval of the request and execution of all applicable agreements are prerequisites to the sharing of data with the requesting party.

Data requests can be submitted starting 9 months after article publication and the data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis.

Data obtained through this study may be provided to qualified researchers with academic interest in obesity/overweight.