Clinical Research

Effectiveness of Active Hydrogen “H(H₂O)m” for Post COVID-19 syndrome

A 10-day clinical trial was conducted starting on October 15, 2021 to evaluate the rehabilitation effect of Active form of Hydrogen H(H₂O)m inhalation towards medical staff with Post COVID-19 syndrome. A paper has been published in “Cardiovascular Therapy and Prevention – Vol 6, 2021”. Study concludes that, inhalation of H(H₂O)m for Post COVID-19 rehabilitation is “a safe and highly effective method”.

Overview and objectives of the research

To study the safety and efficacy of inhaling active form of hydrogen (AFV – H(H₂O)m) for rehabilitation of Post COVID-19 syndrome.

Points revealed from clinical trials

・ Improvement of vascular rigidity
・ Significant increase of 6 minutes walking distance
・ Increased blood oxygen concentration

Subjects were 60 medical frontliner who suffered from Post COVID syndrome for a long time even after recovering.

Participants in this trial were medical staff from D.D. Pletnev City Hospital in Moscow, Russia. Subjects were divided into two groups, the Main group that inhales H(H₂O)m, and the Control group that does not inhale.

Inclusion Criteria

① Infected with the COVID-19 and recovered (rT-PCR test negative)
② Age 18 years and over
③ Agree to informed consent
④ The condition of the lungs is CT2

Subjects complained of the following symptoms:
・Shortness of breath even moving for a little
・Feel tired all the time
・I cannot sleep very well
・Loss of appetite
・ Getting tired easily even for few walk

Exclusion Criteria

・Requires respiratory suppoer
・Taking immunosuppressants or immunomodulators
・Diagnosed with stroke or heart failure within the last 6 months
・A virus of COVID-19 (Sars-Cov-2) detected by rT-PCR test

Equipment used in the trial

In this clinical study, the active form of hydrogen inhaler SUISONIA (FRJ-220V) developed in Japan was used.

FRJ-220V uses an internal heater to generate a mixture of steam containing active form of hydrogen, and this gas is delivered the nostrils through a nasal cannula. This study is how inhaling the gas generated by suisonia FRJ-220V will affect Post COVID-19 syndrome.


Take a look how the clinical trial was conducted.

Data Analysis

Stiffness Index

Stiffness Index (SI) is an index that indicates the hardness of large arteries, and the condition and risk of blood vessels can be evaluated from outside the body using the pulse wave velocity.

The average SI index of the non-inhalation group (Control) increased by nearly 5%, and the average SI index of the inhalation group (Main Group) decreased by nearly 20%.

This data may indicate that the condition of the blood vessels are improving.

Refractive Index

Refractive Index (RI) represents the condition of small blood vessels and compares systolic and diastolic blood pressure to give an index of the flexibility of small arteries. The higher the RI value, the more flexible the blood vessel.

The mean RI values for the non-inhalation group (Control Group) showed slight increase between day 1 and day 10. The average RI value of the main group (Main Group) showed significant increase by nearly 30%, suggesting that the blood vessels became more flexible after inhaling H(H₂O)m.

6 minute walking test

The 6-minute walking distance test is a test in which the subjects walk for 6 minutes on the 1st and 10th days respectively to measure walking distance.

Post COVID-19 syndrome may affect physical strength due to low oxygen levels, therefore this test is one of the important indicator to examine improvement.

The non-inhalation group (Control Group) showed almost no difference between days 1 and 10. However in the Main Group, the walking distance has increased by nearly 40%.

H(H₂O)m may improve exercise tolerance.

Pulmonary Shunt Index

Both the pulmonary shunt index from non-inhalation group (Control Group) and the inhalation group (Main Group) showed a recovery tendency on the 1st and 10th days.

However, in the inhalation group, the decrease was about 50% from the higher average on the 1st day.

It is possible that inhalation of H(H₂O)m may promote to lung recovery.

What is Pulmonary Shunt?

Our lungs have the role of taking in “oxygen” and removing “carbon dioxide” from blood. Normally, the blood that passes through the lungs will completely do this gas exchange.  However, diseases such as COVID-19 can damage our lungs causing blood to bypass lung without gas exchange. This is called shunt.  Normally, the shunt should be 0%.

Since the shunt ratio of the main group that inhaled H(H₂O)m decreased, it is possible that lung condition may be improving.


Inhalation therapy with H(H2O)m in the rehabilitation program of COVID-19 survivors during the recovery period is a safe and highly effective method.

Manifestations of silent hypoxemia and endothelial dysfunction decreased, while exercise tolerance increased.

As for laboratory tests, a decrease in the white blood cell count, estimated pulmonary shunt fraction and lactate content parameters was revealed.

Investigators and Authors of this Clinical Trials 

Prof. Alexander G. Chuchalin MD

Pirogov Russian National Research Medical University. Russian Federation

Academician of the RAS.

professor alexander chuchalin and suisonia FRJ-220V

Details about clinical trial

Shogenova L.V., Truong T.Ch., Kryukova N.O., Yusupkhodzhaeva K.A., Pozdnyakova D.D., Kim T.G., Chernyak A.V., Kalmanova Е.N., Medvedev O.S., Kuropatkina T.A., Varfolomeev S.D., Ryabokon A.M., Svitich O.А., Kostinov M.P., Kunio I., Hiroki M., Chuchalin A.G.
Hydrogen inhalation in rehabilitation program of the medical staff recovered from COVID-19.
Cardiovascular Therapy and Prevention. 2021;20(6):2986. (In Russ.)