# Epsom salt baths and magnesium sprays: can skin absorb magnesium?

Source: https://magnesiumguide.uk/forms/epsom-salts-and-sprays/
Author: Nell Hartley · Updated 2026-11-04

**Short answer:** There is no good evidence that magnesium baths, flakes, oils or sprays raise the body's magnesium. Skin is an effective barrier to charged minerals, and a 2017 review concluded that transdermal magnesium is scientifically unsupported. A warm bath may still help you relax, but if you need magnesium, take it by mouth or eat more magnesium-rich food.

## What are Epsom salts, flakes and magnesium oil?

- **Epsom salts** are magnesium sulphate crystals, about 10% magnesium by weight. They are sold for baths and, separately, as a laxative.
- **Magnesium flakes** are usually magnesium chloride, also for baths and foot soaks.
- **Magnesium oil and sprays** are concentrated solutions of magnesium chloride. They feel oily but contain no oil.

They are marketed as a way to top up magnesium "through the skin", bypassing the gut, for sleep, cramps and recovery.

## Can magnesium get through skin?

Very little, if any. The outer layer of skin is designed to keep water-soluble, electrically charged substances out, and magnesium in solution is exactly that. In 2017 a group of German researchers reviewed the evidence and concluded that the case for transdermal magnesium is scientifically unsupported. The studies that claimed an effect were small, mostly without a control group, and often unpublished or funded by sellers.

In other words, the magnesium in a bath mostly goes down the plughole.

## Why do people feel better after a magnesium bath?

Warm water relaxes muscles, a bath before bed can help you wind down, and expecting to feel better helps too. Those are real benefits, but they don't depend on magnesium. If you enjoy a salt bath, there is no harm in it for most people.

## Are Epsom salts or magnesium sprays risky?

Externally, mainly skin irritation: magnesium oil commonly stings or itches, especially on broken skin or after shaving. Don't use bath salts if you have open wounds or a skin condition without advice.

By mouth, magnesium sulphate is a strong laxative. Take it only as a product labelled for that use, at the stated dose. Too much can cause severe diarrhoea and, rarely, dangerously high blood magnesium. See [constipation](/benefits/constipation/).

## What should you do instead?

If cramps are the reason you're trying a spray, read [magnesium for leg cramps](/benefits/muscle-cramps/) first: oral magnesium doesn't beat placebo for ordinary night cramps either.

If you want more magnesium, eat more [magnesium-rich foods](/basics/food-sources/) or take a well-absorbed oral form such as [citrate](/forms/magnesium-citrate/) or [glycinate](/forms/magnesium-glycinate/). Our [comparison of forms](/forms/) covers the rest.

## Frequently asked questions

### Do Epsom salt baths help sore muscles?

A warm bath can ease aching muscles and help you relax, with or without salt. There are no good trials showing that Epsom salts add anything to the warm water.

### Is magnesium oil better than tablets?

No. There is no reliable evidence that magnesium oil or spray raises magnesium levels, while tablets and capsules clearly do. Magnesium oil is actually a strong solution of magnesium chloride, and it can sting or itch on the skin.

### Can you drink Epsom salts?

Magnesium sulphate taken by mouth is a strong laxative. Only use a product sold for that purpose and follow its directions, because overdoing it can cause severe diarrhoea and, rarely, dangerous magnesium levels.

## References

1. [Gröber U et al. Myth or reality: transdermal magnesium? Nutrients, 2017.](https://pubmed.ncbi.nlm.nih.gov/28788060/)
2. [Bokhari SR et al. Fatal hypermagnesemia due to laxative use. American Journal of the Medical Sciences, 2018.](https://pubmed.ncbi.nlm.nih.gov/29661354/)
3. [NHS. Laxatives.](https://www.nhs.uk/medicines/laxatives/)