Jizo no Yu Spring (Prefectural)
Analysis UnverifiedJizou-no-yu, one of Kusatsu's storied sources, draws its lineage from the Edo period when the town earned renown as a favored resort of the shogunate. This spring flows with particular resonance for those seeking to reset accumulated fatigue and skin sensitivities, embodying Kusatsu's cherished yunomi culture—the ritual beating of hot spring water to cool it for bathing. Travelers seeking authentic thermal immersion and respite from daily stress find themselves especially drawn to its mineral-rich, deeply cleansing character.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.
The source of the distinctive sulfur smell. Dilates blood vessels via skin and inhalation to strongly boost circulation.
Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.
A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.
A trace component with gentle antibacterial and anti-inflammatory action.
Scores are calculated from mineral analysis data based on the Mineral Spring Analysis Guidelines (Ministry of Environment, Japan). They are unrelated to facility atmosphere or service quality.
The temperature, pH and component values shown here are based on the hot spring analysis (source). Actual values in the bath may differ depending on heating, dilution, recycling and filtration. Please check current usage status at the facility.
Given its formidable pH 2.0 acidic nature, Jizou-no-yu demands measured approach. Begin with brief immersions of 3–5 minutes; even with acclimatization, limit sessions to 10–15 minutes maximum. Rinse thoroughly in warm water immediately after bathing to remove mineral residue—essential for those with sensitive skin. Start with 1–2 baths daily, monitoring for thermal irritation as you gradually adjust frequency.
At pH 2.0 with spring temperature of 50.1°C, this water carries 678.5 mg/kg sulfate ions and 314.1 mg/kg chloride ions, delivering potent antimicrobial and keratin-softening properties. Those battling atopic dermatitis, chronic eczema, and psoriasis report particular relief. The 6.9 mg/kg free hydrogen sulfide boosts circulation, alleviating cold intolerance, peripheral vascular dysfunction, and chronic muscular and joint stiffness.
Avoid bathing if you have hypersensitive skin or mucous membranes, or if you experience age-related skin dryness. The strong acidity necessitates rinsing in warm water post-bathing, especially for sensitive-skinned bathers.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- 地蔵の湯(県有)
- Spring type
- 酸性含硫黄-アルミニウム-硫酸塩・塩化物温泉(硫化水素型)(低張性酸性高温泉)
- Source temperature
- 50.1℃
- pH
- 2
- Flow type
- 自然湧出
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2023-08-04
- Analyst organization
- 一般社団法人 群馬県薬剤師会（環境衛生試験センター）
- Registration No.
- 群馬薬第2号
Cations
- Hydrogen ion H⁺
- 9.6 mg/kg
- Sodium ion Na⁺
- 62.9 mg/kg
- Potassium ion K⁺
- 25.7 mg/kg
- Ammonium ion NH₄⁺
- 0.30 mg/kg
- Magnesium ion Mg²⁺
- 39.6 mg/kg
- Calcium ion Ca²⁺
- 73.6 mg/kg
- Aluminum ion Al³⁺
- 46.2 mg/kg
- Manganese ion Mn²⁺
- 1.9 mg/kg
- Iron(II) ion Fe²⁺
- 18.3 mg/kg
- Total cations
- 0.28 mg/kg
Anions
- Fluoride ion F⁻
- 9.6 mg/kg
- Chloride ion Cl⁻
- 314 mg/kg
- Sulfate ion SO₄²⁻
- 679 mg/kg
- Hydrogen sulfate HSO₄⁻
- 218 mg/kg
- Total anions
- 1.2 mg/kg
Undissociated Components
- Metasilicic acid H₂SiO₃
- 234 mg/kg
- Metaboric acid HBO₂
- 9.8 mg/kg
- Total undissociated
- 0.25 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 57.2 mg/kg
- Free hydrogen sulfide H₂S
- 6.9 mg/kg
- Total dissolved gas
- 0.06 mg/kg
Totals
- Total dissolved substances
- 1.8 mg/kg
- Component total
- 1.8 mg/kg
- Evaporation residue
- 1.6 mg/kg
Usage
- Heating
- No
- Dilution
- No
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
Indications & Contraindications
- Bathing indications
- Chronic pain or stiffness in muscles and joints (rheumatoid arthritis, osteoarthritis, lumbago, neuralgia, frozen shoulder, contusion, sprain, etc. in chronic phase), muscle stiffness due to motor paralysis, gastrointestinal dysfunction (feeling of fullness in stomach, gas in intestines, etc.), mild high blood pressure, mild dyslipidemia, mild asthma or emphysema, hemorrhoids pain, autonomic instability, symptoms caused by stress (sleep disorders, etc.), convalescence after illness, fatigue recovery, health promotion, atopic dermatitis, psoriasis vulgaris, impaired glucose tolerance (diabetes), impetigo, chronic eczema, cuts and grazes, peripheral circulatory failure, poor circulation, depression, xeroderma
- Contraindications
- Active phase of disease (especially with fever), active tuberculosis, advanced malignant tumors or severe body weakness due to severe anemia, severe heart or lung disease causing shortness of breath upon slight exertion, severe kidney disease with edema, gastrointestinal hemorrhage, visible bleeding, acute exacerbation of chronic disease, hypersensitivity of skin or mucous membranes, xeroderma in elderly patients
Drinking
- Drinkability
- Not drinkable