Molecular hydrogen therapy in musculoskeletal conditions: An evidence-based review and critical analysis

Table 5 Common hydrogen delivery methods and research dosages

Delivery method	Typical research dosages/concentrations	Administration duration	Targeted systems/conditions	Prospective	Disadvantages
hydrogen-rich water ingestion	0.9 ppm H2 (1260 mL/day - 2520 mL/day)	3 days to 4 weeks	Muscle recovery; RA; neuropathic pain; muscle atrophy	Accessible; convenient for daily/Long-term use; systemic effects	H2 can escape from containers; variability in commercial products
	4-5 ppm H2 (530 mL/day)	1 month
	> 1.5 mmol/L H2 (average 15 mL/day in mice)	Up to 12 weeks
	Proposed therapeutic dose: 80 mL H2 gas (6.6 mg/3.3 mmol) per day
Hydrogen gas inhalation	< 4 % H2 in air; 2.0 L/minute H2 + 1.0 L/minute O2 for 60 minutes	60 min/day over 2 weeks single sessions	Respiratory; cardiovascular; KOA; fibromyalgia; acute conditions (stroke)	Rapid systemic delivery; precise dosing with devices	Requires specialized equipment (inhaler/generator); risk if O2 is insufficient or H2 is contaminated
H2-saturated saline injection	1 ppm H2-saline (500 mL)	Daily for 5 days	RA; acute conditions (ischemic stroke)	Direct and rapid systemic delivery; bypasses GI tract	Invasive; requires medical professional administration
Topical application	Not specified (part of combined treatment)	Not specified (part of combined treatment)	Soft tissue injuries	Localized effect; potentially fewer systemic side effects	Limited systemic absorption; variable penetration
Oral tablets/capsules	Hydrogen-rich coral calcium: 170-1020 mg/day	1 month	Autoimmune diseases (RA, SLE)	Convenient; easy to administer	Absorption variability; potential for other ingredients (e.g., calcium)

RA: Rheumatoid arthritis; KOA: Knee osteoarthritis; SLE: Systemic lupus erythematosus; GI: Gastrointestinal.