Drinking Onsen Water Analysis | Licensed Balneotherapy in Japan

What Is Insatsu (Drinking Onsen Water)? | Culture, Benefits & Safety

Table of Contents

History and Culture of Drinking Spring Water
Suitable Spring Types and Expected Benefits

Q & A

Frequently Asked Questions

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Can you drink the water at any onsen?

Drinking spring water is only permitted at designated spots in facilities that hold a prefectural drinking-spring licence. Do not drink water directly from the source.

How much spring water should you drink?

The facility will specify the recommended amount per serving — typically 100–200 ml — taken a few times a day. Never exceed the recommended dose.

History and Culture of Drinking Spring Water

Drinking spa therapy has flourished in Europe since the Middle Ages. Baden-Baden in Germany and Karlovy Vary in the Czech Republic are world-famous drinking spring destinations. In Japan, select facilities such as Kusatsu Onsen and Hakone-Yumoto Onsen are licensed for insatsu.

Suitable Spring Types and Expected Benefits

Spring Type	Drinking Indication
Chloride spring	Impaired digestive function, chronic constipation
Sulfate spring	Impaired digestive function, biliary disease
Iron spring	Iron-deficiency anemia
Bicarbonate spring	Gout, hyperuricemia (alkalising urine)

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References

EXPLORE RELATED TOPICS

SymptomDrinking Spring Water for Constipation →Spring TypeBicarbonate Springs: "Beauty Waters" for Smooth, Glowing Skin →Spring TypeFerruginous Springs: Iron-Rich, Rust-Red Waters & Their Drinking Indication →

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Drinking Hot Spring Water (Insatsu) | What It Is, Benefits & Safety Rules

Insatsu — drinking hot spring water directly — has a long history in Japan and Europe. Certain spring types are recognised to support digestive and metabolic health, but the practice is strictly regulated and must be done at authorised facilities only.

SYMPTOMSMay 6, 2026· 1min read

Drinking Spring Water for Constipation | Chloride, Sulfate & Bicarbonate Springs

Japan's official indications list constipation for drinking chloride and sulphate springs. Their mineral constituents are said to act on the intestinal tract to stimulate peristalsis. Drinking should only be done at licensed facilities under medical guidance.

SPRING TYPEMay 5, 2026· 2min read

Bicarbonate Springs: "Beauty Waters" for Smooth, Glowing Skin

Bicarbonate springs (HCO₃⁻ as the main anion) are known as "the beauty waters" because bicarbonate gently removes dead skin cells and sebum, leaving skin silky smooth. Indicated for bathing (cuts, cold sensitivity, dry skin) and drinking (gastroduodenal ulcers, diabetes, gout).

SPRING TYPEMay 5, 2026· 1min read

Ferruginous Springs: Iron-Rich, Rust-Red Waters & Their Drinking Indication

Ferruginous springs contain iron ions (Fe²⁺ + Fe³⁺) at 20 mg/kg or more. Clear at the source, they turn reddish-brown or golden on contact with air. Iron-deficiency anemia is its official drinking indication.