Hydrogen water tablets: side effects and safety.
The short answer
For most healthy adults, the part of a hydrogen tablet worth watching is not the hydrogen but the magnesium that produces it. Each Thriviom tablet contains 80 mg. The NIH sets the upper limit for magnesium from supplements at 350 mg a day for adults, because more than that can cause diarrhea, nausea and cramping1. One tablet a day sits well inside that, but other magnesium you take counts too.
Key takeaways
- The tablet releases hydrogen when magnesium reacts with water; what is left behind is magnesium.
- Thriviom tablets: 80 mg magnesium each, 19% of the daily value.
- Adult upper limit for supplemental magnesium: 350 mg a day1.
- Ask your doctor first if you have kidney disease or take antibiotics, bisphosphonates or diuretics1.
What is in a tablet
A hydrogen tablet is a small chemistry set. Elemental magnesium reacts with water and food acids, releasing hydrogen gas as fizz and leaving dissolved magnesium behind.
Thriviom’s unflavored tablet lists one active, magnesium at 80 mg (19% of the daily value), and four other ingredients: dextrose, malic acid, L-tartaric acid and adipic acid. One tablet is one serving, dissolved in 8 to 12 oz of water.
Side effects to know about
The side effects to expect come from the magnesium. High intakes of supplemental magnesium can cause diarrhea, nausea and abdominal cramping, which is why the upper limit is set where it is1. That limit counts magnesium from supplements and medicines only, not magnesium naturally present in food1.
In practice, if you already take a magnesium supplement, a magnesium-based laxative or antacid, add those up before adding a tablet. Loose stools are the usual first sign you are taking more than you need.
The hydrogen itself has not been a focus of safety concern in the research reviewed on this site; the open questions there are about how much benefit it gives23.
Who should check with a doctor first
People with kidney disease, because the kidneys clear excess magnesium and that clearance is reduced1.
People taking medicines that magnesium interacts with. The NIH lists bisphosphonates for osteoporosis, tetracycline and quinolone antibiotics, which magnesium can stop being absorbed properly if taken too close together, as well as some diuretics and long-term acid reducers that change magnesium levels1.
Anyone pregnant or nursing, as with any supplement.
How to take them
Drop one tablet into 8 to 12 oz of water and let it dissolve for one to three minutes; the water turns hazy white for a moment. Drink it soon after, because hydrogen escapes from an open glass. Follow the directions on the label.
Common questions
Are hydrogen water tablets safe?
For most healthy adults taking them as directed, yes. The main thing to track is magnesium: keep your total from supplements and medicines under 350 mg a day, and ask your doctor first if you have kidney disease or take interacting medicines.
Can hydrogen tablets upset your stomach?
They can, mostly because of the magnesium. Loose stools, nausea or cramping are signs of too much supplemental magnesium. Take fewer, or stop and check your total intake.
How many hydrogen tablets can I take a day?
Follow the label. Each Thriviom tablet has 80 mg of magnesium, so count every tablet toward the 350 mg daily limit for supplemental magnesium, along with any other magnesium you take.
Can I take hydrogen tablets with medication?
Magnesium can interact with some antibiotics, osteoporosis medicines and diuretics. Space them as your pharmacist advises, and ask before starting if you take any of these.
Where Thriviom fits
Hydrogen Water Tablets
Every amount printed on the label, every batch tested by an independent lab, and the report for your lot is yours to look up. Read the full ingredient guide first if you are weighing it up.
Sources
- NIH Office of Dietary Supplements Magnesium: Fact Sheet for Consumers. National Institutes of Health, accessed October 2026.
- Dhillon G, et al. Hydrogen Water: Extra Healthy or a Hoax? A Systematic Review. International Journal of Molecular Sciences, 2024.
- Zhou K, et al. Effects of molecular hydrogen supplementation on fatigue and aerobic capacity in healthy adults: a systematic review and meta-analysis. Frontiers in Nutrition, 2023.
This article is for general education and is not medical advice. Talk to your doctor or pharmacist before starting a supplement, especially if you are pregnant, nursing, or take any medication. These statements have not been evaluated by the Food and Drug Administration. Thriviom products are not intended to diagnose, treat, cure, or prevent any disease.