What you're actually soaking in
The mineral menu
Every spring has its own chemistry, and each mineral brings its own colour, feel and tradition. Here is what sulfur, silica, magnesium and the rest actually do — and which springs are richest in each.
8 minerals · sorted by what they're good for
Sulfur
The smell you learn to love — and the classic skin-soak mineral.
Magnesium
The muscle-and-sleep mineral — the reason an Epsom soak feels so good.
Common questions
Are mineral hot springs actually good for you?
Soaking in warm mineral water is reliably relaxing and is traditionally used to ease muscle aches, support circulation, and soothe some skin conditions. The heat and buoyancy do much of the work; the dissolved minerals (sulfur, silica, magnesium and others) add their own traditional associations. Evidence varies by mineral and condition, so treat soaking as restorative rather than medical.
Which minerals in hot springs are best for skin?
Sulfur and silica are the two most associated with skin. Sulfur has mild antibacterial, skin-softening properties and a long history with eczema, psoriasis and acne; silica leaves a soft, smooth feel and is the basis of geothermal mud masks.
How long should you soak in a mineral hot spring?
Most guidance suggests 15–20 minutes at a time, cooling off between rounds, and staying hydrated. Leave the water if you feel light-headed, and soak shorter and cooler if you are new to it.
Is the sulfur smell in hot springs harmful?
No. The "rotten-egg" smell is hydrogen sulfide gas and is harmless at the low concentrations of a bathing spring. Soak in well-ventilated areas, and note that sulfur can tarnish silver jewellery — take it off first.
The information here is for general interest, not medical advice. If you are pregnant or have a heart condition, low blood pressure, or a chronic illness, check with a doctor before hot mineral soaking.