That’s a great question—and it’s actually something scientists are still studying. But based on current animal and human research, most studies use about 0.5 to 1.6 milligrams (or more) of hydrogen gas (H₂) per day, and those amounts have shown real health benefits.

For example, if your hydrogen water has a concentration of 1 mg per liter (which is the same as 1 ppm), drinking two liters would give you 2 mg of H₂. While the ideal amount might be different for each person or condition—sometimes lower, sometimes higher—these are the general ranges where positive effects have been observed. The great thing is you cannot overdose on molecular hydrogen and you can drink H2 water throughout your day as you #1 hydration choice.