Table 1.

Administration routes of molecular hydrogen in human bodies to combat various infections and/or diseases, along with the respective management strategies.

Administrative Routes in the Body	Subject/s (Time Taken to Initiate an Action)	Human Body Response/s	Effects on Target Organ or at Injury Site	Administration Protocol	Advantages	Prospective Risks Associated	Ref.
Dissolved H2 Saline	Rats (24 h)	Anti-inflammatory and anti-apoptotic effect	Myocardial I/R injury	10 mL/kg, 0.6 mmol/L,	Direct exposure or inoculation of dose at the target site	Cross-infection, Invasive	[30]
	Mice (12 h)	Anti-inflammatory response, reduces sepsis associated diseases	Encephalopathy	5 mL/kg, 0.6 mmol/L	Direct exposure or inoculation of dose at the target site	Cross-infection, Invasive	[31]
Drinking of dissolved H2 water	Human (2 weeks)	Alleviates Injuries	Injured soft tissues (sports-related)	2 g/day, H2-rich tablets	Safe and portable	Dose intake limitations	[32]
	Human (4 weeks)	Reduction in inflammation and anti-apoptotic	Peripheral blood vessels and blood cells	1500 mL/day, 0.753 mg/L	Safe and portable	Dose intake limitations	[33]
	Human (8 weeks)	Improves parapsoriasis	Plaques	10–15 min bathing with H2 water (two times a week)	Safe and portable	Dose intake limitations	[11]
	Guinea Pig (10 days)	Immunoregulation and improves allergic rhinitis	Allergic rhinitis	0.6 mmol/L, 20 μL/day Inoculated through nasal passage	Safe and portable	Dose intake limitations	[34]
	Mice (10 days)	Anti-inflammatory response	EAE 1 symptoms;	0.89 mM/0.36 Twice/day	Safe and portable	Dose intake limitations	[35]
H2 gas inhalation through nasal routes	Rats (120 min)	Antioxidant, protects from cerebral injury	Cerebral injury (I/R)	4, 1, or 2% H2	Dose and intake time can be ensured	If concentration rises above 4%, it may be explosive	[2]
	Rats (4 months)	Anti-inflammatory, ameliorates COPD	COPD 2 symptoms	2, 22 or 41.6% H2 For 2 h (Once/day)	Dose and intake time can be ensured	If concentration rises above 4%, it may be explosive	[36]
	Human (7 days)	Anti-inflammatory, ameliorates COPD	COPD symptoms	6 to 8 h/d, 66.6% H2	Dose and intake time can be ensured	If concentration rises above 4%, it may be explosive	[37]
	Human (daily till discharge)	Ameliorates COVID-19	COVID-19	66.6% H2 33.3% O2	Dose and intake time can be ensured	If concentration rises above 4%, it may be explosive	[38]
H2 administration into the body via nanoparticles	Rats (3/24 h)	Antioxidant, anti-inflammatory, ameliorates lung and myocardial injuries	Myocardial injury (I/R), lung injury	4 × 109 or 2 × 1010 bubbles	Safe to use, high H2 content/unit volume	Expensive	[10]

¹ EAE: experimental autoimmune encephalomyelitis; ² COPD: chronic obstructive pulmonary disease.