For such a simple, vital resource, water can get pretty complicated once it's bottled in aesthetically-pleasing vessels. Purified? Spring? Volcanic? Electrolytes? Natural flavors? pH Balanced? If that wasn't confusing enough, another kind of water is quickly taking over our grocery shelves: hydrogen water—or HWater. And it might be the most confounding type thus far.
We've heard of celebs like Blake Lively, Ryan Reynolds, and Zac Efron drinking the stuff, but what is it? HWater is simply hydrogen gas dissolved into water. It's not alkaline water (less acidic water that has its own cult following), and it's not H3O+ either (water molecules with extra hydrogen on them). HWater is having a moment as companies from beauty brand Dr. Perricone to hydrogen water brand HFactor claim that adding more hydrogen to water increases energy, improves recovery after a workout, and reduces inflammation. From $3 pouches to $1,000 hydrogen-infusing machines and $60 molecular hydrogen tablets you toss into your normal water on-the-go, marketing is having a field day off this latest health trend (in Japan, people are even bathing in it).
Yet the research is scant and findings are still in early development stages. They hardly back up the many "elixir of life" claims by HWater-touting companies. And when scrutinized under a hoax-croscope, there are only general theories to be found and zero hard evidence.
Short story? We’re skeptical. Here's why.
The idea behind HWater isn't pure marketing—research on mice has shown that hydrogen acts as an effective disease-fighting antioxidant and that drinking HWater can potentially prevent arteriosclerosis (hardening of the arteries). Similar studies in rats show that supplementing hydrogen also had anti-inflammatory properties indicating that HWater can effectively carry hydrogen to damaged cells.
One study on humans found that hydrogen water could be a “therapeutic and and preventative strategy for metabolic syndrome (e.g., obesity, insulin resistance, hypertension).” In an 8-week study observing 20 people who were given drinking water containing a metallic stick to produce hydrogen-rich water, researchers saw a 39% increase in antioxidants, an increase in HDL (aka, good cholesterol), and a decrease in total cholesterol. That's promising news, but very limited data. We'd need to see a study done on a much larger sample size over a longer period of time having subjects drink HWater from a can or pouch before brands can claim antioxidant and anti-inflammatory properties. And that doesn't even touch whether it's worth shelling out $3 per 11 ounces that you’re advised to consume several times a day. In contrast, you can get an 11-ounce bottle of Fiji Natural Artesian Water for $1.32.
While rodents closely resemble humans in terms of diseases, obviously we’re not the same. Furthermore, when it comes to federal regulations on claims, there aren't really any—neither for the aluminum packaging (FYI: hydrogen gas can escape through glass or plastic) nor for the recommended dosages. “We don’t know anything about dosing or the frequency you need to drink hydrogen water to get health benefits,” Robin Foroutan, a dietitian and spokesperson for the Academy of Nutrition and Dietetics tells TIME.
So regardless of whether the real deal works wonders or not, we don't know how much it stands to benefit your health. The good news? If you really want to try it—perhaps you suffer from chronic inflammation or low energy levels—it won't hurt you. So far the only thing the FDA has concluded is HWater is Generally Recognized as Safe (“GRAS”).