What is a magnesium jacuzzi?

What it actually is

A warm jacuzzi dosed with magnesium chloride rather than plain water — the same mineral behind Epsom-salt baths, at a concentration designed to sit on the skin rather than needing to be absorbed through digestion. A soak typically runs around 30 minutes, in water warm enough to relax into but not so hot it works against the point of the exercise.

What the mineral does

Magnesium absorbed this way is linked to muscle relaxation and, for many people, noticeably deeper sleep the same night. Transdermal absorption of magnesium is real but modest — the research on exactly how much reaches your bloodstream through skin is thinner than the marketing around magnesium products generally suggests. What's well established regardless is that a warm 30-minute soak relaxes muscles and lowers stress on its own, mineral content aside; the magnesium is a genuine bonus on top of an already-good soak, not the entire mechanism.

How long to soak

Around 30 minutes is the house guidance. It is the gentlest of the three main stages, so there's less of a hard ceiling than with heat or cold exposure — but 30 minutes is enough to get the relaxation benefit without your skin pruning past the point of comfort.

Why it's the finishing step

Finish here, not start here, is the house rule. A magnesium jacuzzi is deliberately the mellowest stage — it works best as the wind-down after sauna and ice bath, or the deep-rounds contrast circuit, rather than as an opener before more demanding heat or cold exposure. Starting your session here tends to make the sauna and ice bath that follow feel like a step backward rather than a progression.

How it compares to an Epsom bath at home

Same mineral, different delivery and scale — a jacuzzi holds far more water than a bathtub, at a controlled temperature, for longer than most people manage in a home tub before the water cools. The relaxation effect of a proper warm soak is the larger part of what you're getting either way; a jacuzzi just makes it easier to do properly and for the full 30 minutes.

Who should take it easy

A warm soak is gentle by design, but check with a doctor first if you have a cardiovascular condition or are pregnant, since prolonged warm-water immersion raises heart rate and core temperature more than people expect. The full longevity circuit is restricted to guests 18 and over, a stricter line than the hotel's general 14+ policy; massage and the rituals menu remain open from 14.

Written by the team at The KOHO Air Hotel, a boutique wellness retreat five minutes’ walk from Gili Air harbour. We answer these questions by message most days — just ask.

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