One woman on TikTok said that it had cured her sore throat and fever. Another wrote that it can help you lose weight, increase energy and strengthen your immune system. Drink hydrogen water, some product advertisements go on to say, and you’ll enjoy reduced pain and inflammation, improved gut health, superior hydration, increased endurance, a better mood and even slowed signs of aging. Hydrogen water is made by simply adding more H’s into your H2O. But when it comes to its purported health advantages, researchers are skeptical.
“For almost every study that’s shown a benefit, there’s another study that questions the benefit,” said Dr. Mitchell Rosner, a kidney doctor who specializes in fluid and electrolyte disorders at UVA Health in Charlottesville, Virginia. Here’s what we know.
What is hydrogen water?
Hydrogen water is often packaged in sleek drink pouches or aluminum cans. Some brands sell dissolvable hydrogen tablets that you can plop into your water, or high-tech bottles that you fill with regular water and then infuse with hydrogen by pressing a button. Some of these drinks, also called hydrogen-rich and hydrogen-infused water, have added flavors or electrolytes, but the basic product involves regular water plus hydrogen gas molecules, or H2, mixed in. Because hydrogen molecules are extremely small, they easily dissolve in water, said Dr. Gagandeep Dhillon, an assistant medical director at the University of Maryland Baltimore Washington Medical Center. They also don’t create the same fizzy sensation as seltzer or soda. Those contain carbon dioxide, a larger molecule.
Hydrogen is so small and light that it also easily escapes water, Dhillon said. To ensure the molecules stay put, some brands package their product in special aluminum containers or recommend drinking their product within 30 minutes of opening it.
Doesn’t water already contain hydrogen?
All water molecules have two hydrogen atoms and one oxygen atom, as shown in its chemical name, H2O. But once those atoms combine into one water molecule, Dhillon said, our bodies can’t make use of the hydrogen and oxygen separately.
The idea behind hydrogen water is that the accessible hydrogen molecules — the ones that aren’t bound to oxygen — can enter our body’s cells and generate an antioxidant effect, Rosner said.
Most of the touted health benefits, which also include enhanced exercise performance, speedier injury recovery, clearer skin and fewer allergy symptoms, come from the idea that hydrogen has antioxidant effects.
What does the science suggest?
The science backing the health claims of hydrogen-infused water is shaky at best, said Henry Jay Forman, an emeritus professor of gerontology at the University of Southern California. Scientists already disagree about whether supplementing your diet with extra antioxidants can improve your health, he said. And even if hydrogen gas lowers inflammation in lab studies, the same won’t necessarily be the case inside our bodies.
Few studies supporting the drink’s benefits have been performed in humans. And they are small and often contradictory. In one 2020 study of 16 male athletes, researchers found that hydrogen-infused water improved the race times and fatigue levels of the four slowest runners — but not of the four fastest runners — in the group. But a 2021 study of 37 trained and untrained cyclists had different results: Only the trained cyclists benefited from hydrogen-rich water in terms of endurance, speed and fitness when compared with the untrained cyclists.
In a review of 30 hydrogen water studies published in January, Dhillon and his colleagues set out to see whether the drink had any health benefits. While some of the studies were encouraging, he said, they couldn’t draw any clear conclusions.
“More studies are needed to see if drinking hydrogen-infused water can reduce inflammation, aging or disease,” said Tamara Hew-Butler, a sports medicine researcher at Wayne State University. Hew-Butler said some companies also sold oxygen-infused water, which your body doesn’t need.
Still, some people say they feel real benefits from hydrogen-infused water. Forman said this might be because of the placebo effect, in which people feel better because they believe it works.
Is hydrogen water safe?
Although the benefits are murky and drinking too much water in general can be dangerous, Rosner said that hydrogen-infused water wasn’t linked to any serious health risks.
“Everything I’ve read seems to say there’s no downside,” he said. The Food and Drug Administration considers hydrogen-infused water to be “generally recognized as safe,” as long as the hydrogen molecules make up no more than 2.14% of the drink. Determining this percentage can be tricky since companies aren’t required to disclose it on product labels.
Hydrogen-infused water can come with a high price tag — some of the fancy make-it-yourself bottles can cost around $100 — which is why both Rosner and Forman said it might not be worth it without more proven benefits.
“If you have $100 and want to improve your health, you’re probably better off buying $100 of fresh fruits and vegetables than two cases of hydrogen water,” Rosner said.
This article originally appeared in The New York Times.