The smallest molecule in nature, taken as hydrogen-rich water or inhaled gas. Its most consistent signals are modest: less fatigue and perceived effort around exercise, small improvements in blood fats and metabolic markers. Benefits are clearest in those starting with higher oxidative stress; many studies found no effect. Very well tolerated — a low-risk option with real but modest benefits. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Total cholesterol | 150–200 mg/dL | Primary lipid outcome with trial support |
| LDL cholesterol | <100 mg/dL (lower if high cardiovascular risk) | Reduced in hydrogen-rich-water lipid trials |
| Triglycerides | <90 mg/dL | Showed the largest pooled lipid reduction |
| Fasting glucose | 75–90 mg/dL | Tracks possible metabolic benefit |
| Fasting insulin | 2–5 µIU/mL | Detects insulin-sensitivity shifts before glucose changes |
| HbA1c | <5.4% | Captures longer-term glycemic effect |
| ALT | <25 U/L (men), <20 U/L (women) | Liver-stress marker reduced in some trials |
| AST | <25 U/L | Complements ALT for liver status |
| hs-CRP | <1.0 mg/L | Tracks anti-inflammatory effect, if any |
| Oxidized LDL or d-ROMs | Lower is better (assay-specific) | Directly probes the proposed mechanism |
Cadence: Baseline before starting, then recheck metabolic and lipid markers at ~8–12 weeks, then every 6–12 months if continued; qualitative self-assessment ongoing throughout.