Regular water (H₂O) with extra molecular hydrogen (H₂) dissolved in it — similar to how carbon dioxide is added to sparkling water. The hydrogen isn't chemically bonded to the water; it's free-floating dissolved gas. Molecular hydrogen is classified as Generally Recognised As Safe (GRAS) and has been the subject of extensive peer-reviewed research.

Yes, but the hydrogen in H₂O is chemically bonded to oxygen. Hydrogen water contains additional free molecular hydrogen (H₂) dissolved in the water — not chemically bonded. This is the form studied in over 1,400 peer-reviewed research papers.

SPE (Solid Polymer Electrolyte) and PEM (Proton Exchange Membrane) technology separates hydrogen from other gases during electrolysis. When tap water is electrolysed, chlorine and ozone can be produced as byproducts. The PEM blocks these from reaching the drinking water, and our gas release valve vents them safely out of the bottom of the unit.

Fill with tap or filtered water, press the button once for a 5-minute cycle or twice for a 10-minute cycle, wait for it to finish, and drink. Best consumed immediately or within 30 minutes, as hydrogen gradually escapes over time.

Any tap or filtered water works. Filtered water is preferred as it allows for higher hydrogen concentrations, but tap water is fine — the gas venting system removes chlorine and other byproducts that might be present in standard tap water.

You'll see tiny bubbles (similar to champagne) during the cycle, and the water has a noticeably smoother taste. For precise verification, you can use H2 Blue reagent test drops (available separately) to confirm hydrogen concentration. You can also smell waste gases being vented from the base during operation.

Hydrogen is the smallest molecule in existence and begins escaping the moment you open the lid. 280ml is designed to be drunk in one sitting so you get the full concentration. A larger bottle means hydrogen levels drop significantly before you finish. You can generate a fresh batch whenever you want.

To achieve 3000ppb, the bottle must pressurise during electrolysis. Glass cannot safely handle this internal pressure. Our BPA-free, food-grade polymer is specifically engineered to withstand the pressurised environment needed for supersaturation.

Once a week for typical daily use (2-3 bottles per day). Each charge lasts 12-15 cycles. Charges fully in 2-3 hours using any USB-C cable.

No — heat causes molecular hydrogen to escape rapidly. Use cold or room temperature water only. Hot drinks can also damage the membrane.

60-day money-back guarantee on all orders. It is generally expected for you to have used the bottle consistently in order to qualify for the guarantee. Contact our UK-based support team at info@dousewater.co.uk and we'll arrange a full refund. The bottle also comes with a 12-month warranty covering manufacturing defects.