Water knowledge

Kangen water: what’s behind the trend

Kangen water is tap water that an electrolysis device has split into an alkaline and an acidic portion. “Kangen” does not denote a type of water but the ionisers made by the Japanese manufacturer Enagic. The artificially raised pH is chemically real but fleeting – and the advertised health effects are not scientifically proven.

Updated August 2026 · 6 min read

What is Kangen water?

Behind the name stands the Japanese company Enagic, which manufactures water ionisers and had “Kangen” registered as a trademark; the word roughly means “return to the origin”. Technically, Kangen water is ionised tap water: the device is connected to the tap, pre-filters the water and then uses electrolysis to split it into an alkaline portion for drinking and an acidic portion intended for cleaning purposes.

The devices offer several pH levels, from strongly acidic at around pH 2.5 to strongly alkaline at around pH 11. According to the manufacturer, both extreme levels are expressly not drinking water. Intended for drinking are the middle levels between pH 8.5 and 9.5. For comparison: tap water in Switzerland is usually in the neutral to slightly alkaline range, depending on the rock in the catchment area.

How does a water ioniser work?

Inside the device sit electrode plates, usually made of platinum-coated titanium, separated by an ion-permeable membrane. When a voltage is applied, the ions dissolved in the tap water migrate: positively charged minerals such as calcium and magnesium gather on one side, negatively charged ones such as chloride or sulphate on the other. This creates alkaline water with a surplus of hydroxide ions at the cathode, and its acidic counterpart at the anode.

The crucial point: electrolysis adds nothing to the water. It merely rearranges what the tap water already contains. That is why the process needs mineral-bearing water as its raw material – distilled water conducts virtually no electricity and cannot be ionised in the first place.

Why the pH from the device does not stay stable

The pH from the ioniser is a snapshot. It rests on a surplus of hydroxide ions that lacks any material basis: there are hardly any additional minerals that could hold the value. Once the water comes into contact with air, carbon dioxide dissolves in it, forms carbonic acid and pulls the pH back towards neutral. Depending on storage, this takes hours to a few days.

Naturally alkaline mineral water comes by its pH in a different way: on its passage through the rock it dissolves hydrogen carbonate and other minerals that chemically buffer the value. This pH remains stable because it is embedded in the composition of the water itself. How the two variants differ in detail is shown in the article What is alkaline water?.

What does science say about Kangen water?

The advertising promises surrounding ionised water are extensive. Frequently mentioned are:

• Better absorption in the body thanks to supposedly smaller “water clusters”
• An antioxidant effect due to a negative redox potential
• Support for the acid–base balance
• More energy and general wellbeing

For none of these claims is there robust scientific evidence. The cluster hypothesis does not stand up physically: water molecules constantly rearrange themselves within fractions of a nanosecond; stable small clusters that the body could absorb more easily do not exist.

The legal position is clear as well. In the EU, foods may only carry health claims that have been assessed by the European Food Safety Authority (EFSA) and authorised by the European Commission. For ionised or alkaline water there is not a single authorised claim. Switzerland has comparable rules, and disease-related claims are generally prohibited for foods, water included. Such advertising statements are therefore not permitted in this country.

A look at physiology explains why the scepticism is justified. The stomach works at a pH of roughly 1.5 to 3.5 and largely neutralises alkaline water before it reaches the intestine. The body keeps the pH of the blood constant between 7.35 and 7.45 in any case – via breathing and kidney function, regardless of what you drink.

What water demonstrably does is unspectacular and central at the same time: it maintains the body’s fluid balance. As a guide value, the EFSA cites around 2.0 litres of total fluid per day for women and 2.5 litres for men, from drinks and solid food combined. A particular pH is not a prerequisite for this.

Water is a food, not a medicine. If you have health complaints or would like to adjust your diet for medical reasons, discuss this with your doctor.

Direct sales: how do the devices reach their buyers?

Enagic sells its ionisers through direct sales: self-employed distributors broker the devices and receive commissions, in some cases across several referral levels. The purchase costs several thousand francs, with filter changes and maintenance on top. Anyone considering a purchase is best advised to treat it like any major investment: measure the advertising claims against the documented facts, compare prices and obtain commitments on returns and warranty in writing.

Is there alkaline water without a device?

Yes. Water also becomes alkaline in nature when it travels through suitable rock for long enough, dissolving buffering minerals along the way. Such springs are rare, but they do exist, in Switzerland too. Their pH needs neither electricity nor a membrane and survives storage and contact with air, because it is supported by minerals.

One example is Piz Sardona from the Castels spring in Mels: the water spends around twelve years travelling through the rock and stone layers of the Sardona Alps before it is captured with a natural pH of 8.0 – supported by 133 mg of hydrogen carbonate, 87 mg of calcium and 35 mg of magnesium per litre. No device, no electrolysis. The value is part of the water, not a temporary state.

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