Table 2.

Summary of antitumor effects of molecular hydrogen (H₂) in human clinical trials.

Cancer Types	No. of Patients	Administration Periods	Effects of Molecular Hydrogen (H2)	Ref. No.
Colorectal cancer	55	3-months	Inhalation of H2 gas prolonged progression-free survival and overall survival in patients with stage IV, and the mechanism involved the recovery of CD8+ T cells.	[39]
Lung cancer	42	60-months	The combination of H2 gas and Nivolumab showed prolonged overall survival, and the mechanism involved increased coenzyme Q10.	[40]
Lung cancer, liver cancer, pancreatic cancer, etc.	82	At least 3-months	Inhalation of H2 gas in patients with stage III or IV resulted in complete (CR) and partial remission (PR), with a disease control rate of 57.5%.	[41]
Gallbladder cancer	1	10-months	A case study of a patient with gallbladder cancer whose primary tumor was in the liver showed that inhalation of H2 gas had a tumor-reducing effect.	[42,43]
Brain tumor	1	4-months	A case study of a patient with a brain tumor whose primary tumor was lung cancer showed that inhalation of H2 gas had a tumor-reducing effect.	[44]
Lung cancer	48	5-months	Treatment with H2 gas inhalation alone (10 patients) or in combination with anticancer drugs (38 patients) prolonged progression-free survival in lung cancer patients.	[45]
Lung cancer	20	2-weeks	Inhalation of H2 gas improved adaptation and innate immune senescence in lung cancer patients.	[46]