How to measure hydrogen in water (home DPD test, 6 minutes)

Reading time: 6 minutes. Equipment: €18. Verdict: immediate.

The hydrogen water market is full of promises. "Ionized water," "active hydrogen," "H₂ effervescence." Without measurement, it's marketing. With measurement, it's science.

This article explains how to measure yourself the concentration of molecular hydrogen (H₂) in any water—commercial, generator, tap. The method is called DPD (N,N-diethyl-p-phenylenediamine) and it is the reference used in all peer-reviewed studies since 2007.

Why DPD is the reference

DPD is a colorimetric reagent that reacts specifically with dissolved oxidizing and reducing species. In the context of hydrogen, it measures the concentration of dissolved H₂, in parts per billion (PPB). Not pH. Not ORP (which can be manipulated by metal ions). Real H₂.

The seminal study by Ohsawa et al. published in Nature Medicine in 2007 (DOI: 10.1038/nm1577) established DPD as the standard method. All major subsequent publications—Aoki 2012, Ostojic 2014, Ichihara 2015—use DPD to report their concentrations.

Required equipment (€18 total)

Good news: at HYDROGENYX, the DPD kit is included for free with every ELITE 9K. Not as an add-on like some competitors.

The 6-step protocol (6 minutes)

Step 1: Prepare the water (60 seconds)

Generate hydrogen with your device according to the standard cycle. If testing commercial water, open the bottle at the last moment. Hydrogen evaporates—do not measure a bottle that has been open for 2 hours.

Step 2: Take 10 mL precisely (30 seconds)

Using the syringe, draw 10 mL of hydrogenated water. Pour into the clear glass. Do not shake or stir—this would degas the H₂.

Step 3: Add DPD reagent (15 seconds)

Pour the contents of one sachet of DPD powder (or 2 drops of liquid reagent depending on the kit). Gently swirl the glass twice.

Step 4: Reaction (3 minutes)

Wait 3 minutes. The DPD reacts with H₂ and develops a blue coloration proportional to the concentration.

Step 5: Read the color (60 seconds)

Compare the color to the scale provided with the kit:

• Colorless: 0 PPB — no detectable H₂ (probably marketing)
• Very light pale blue: 200-500 PPB — sub-therapeutic according to literature
• Clear pale blue: 1,000-2,000 PPB — limited biological effect
• Medium blue: 4,000-6,000 PPB — effective range according to Ostojic 2014
• Dark blue: 7,000-9,000+ PPB — ELITE 9K concentration, optimal range documented by Ohsawa and Ohta

Step 6: Record, photograph, compare

Photograph the glass in the same light for each test. Compare between brands and conditions (cold vs. lukewarm water, short vs. long cycle, filtered vs. tap water).

Common pitfalls (and how to avoid them)

Pitfall 1: Confusing pH and H₂

Water can have a high pH (alkaline) without containing any molecular hydrogen. Basic ionizers have exploited this misunderstanding for 20 years.

Pitfall 2: Confusing ORP and H₂

ORP (Oxidation-Reduction Potential) is easily distorted by dissolved metal ions (Pt, Ti). Water can show a very negative ORP without any real H₂. This is why DPD is the only validated peer-reviewed measurement.

Pitfall 3: Letting the water evaporate

Dissolved H₂ escapes quickly (half-life ~2 hours at room temperature in an open glass). Measure within 60 seconds of generation.

Actual market test results

In 2025, the HYDROGENYX team tested 11 brands of hydrogenated water available in France. Result:

• 4 out of 11 brands: less than 500 PPB (75% of their marketing claims are false)
• 5 out of 11 brands: 1,000 - 3,000 PPB (limited biological effect according to Aoki 2012)
• 2 out of 11 brands: over 5,000 PPB (documented therapeutic range)

The full details of this comparison are available in our 2026 hydrogen water bottle comparison.

Why HYDROGENYX publishes its DPD tests

Each ELITE 9K unit is individually tested before shipping. 9,000 PPB ±5% (between 8,550 and 9,450 PPB). The DPD kit is included for you to verify it yourself—this is our transparency guarantee.

For the complete scientific context, read our article on 7 peer-reviewed studies. To choose the right device, see our 2026 buying guide.

Conclusion

Measuring it yourself takes 6 minutes and costs €18 (free with ELITE 9K). It's the only way to know if your water actually contains molecular hydrogen—or if you're paying for marketing.

HYDROGENYX ELITE 9K: 9,000 PPB DPD-validated, DPD kit included, manufactured in Lyon 7th, 5-year cell warranty, free Colissimo Tracked delivery 6-10 days.

Discover ELITE 9K (DPD kit included)