Do Epsom salt baths give you enough magnesium for sleep?

What is Epsom salt?

It is a naturally occurring mineral compound that contains magnesium, sulphur and oxygen. It’s also known as magnesium sulphate. Magnesium is an essential mineral involved in over 300 biochemical reactions and is needed in energy production, protein synthesis, muscle and nerve function, blood glucose control, digestion and blood pressure regulation. It helps regulate neurotransmitters directly related to sleep and stress response. It strengthens the way nerve cells communicate with each other and balances the body’s stress-response system.

Will an Epsom salt bath help the body absorb magnesium?

The basic theory of Epsom salt’s effectiveness suggests that magnesium and sulphate dissolve in warm water, so that bathers can absorb them through the skin, or inhale them in steam. “But there is no scientific paper yet which proves that Epsom salt can impact body processes significantly or act as a sleep aid,” says Dr Navita Purohit Vyas, pain management specialist at Kokilaben Dhirubhai Ambani Hospital, Mumbai.

Dr H Guru Prasad, internal medicine expert at CARE Hospital, Banjara Hills, Hyderabad, says that the magnesium-replenishing properties of Epsom salt got extrapolated from traditional belief systems rather than science. “Even if magnesium leaches out in warm water, it would be in micro amounts that would not be enough to have a therapeutic effect. Which means you would have to literally douse yourself in salt-heavy water like the dense Dead Sea. That’s an impossibility. Besides, no data bears out this curative effect or shows that humans can absorb significant amounts of magnesium through the skin. The skin acts as a protective barrier and is not as absorptive anyway,” he says.

Why then do people feel relaxed after an Epsom salt bath?

Topical use of magnesium sulphate, as in soaking your feet in water, can only reduce swelling, says Dr Vyas. Warm baths and soaks anyway relieve tension and pain, loosen muscles and even help reduce blood pressure as blood capillaries open up, she adds. Dr Guru Prasad attributes the relaxing feel after a hot bath to skin pores opening up and allowing the natural release of oil and sweat. “You don’t need Epsom salt for it,” he says.

Misuse can lead to side effects

In fact, Dr Vyas has had a patient who ingested Epsom salt orally, thinking that would help him fall asleep, and landed in hospital because of hypermagnesemia or excess magnesium. “This can damage kidneys and lower blood pressure,” she says.

How else should one have magnesium?

Women aged 19 and older need 310 milligrams (mg) of magnesium per day, and 350 mg if they are pregnant. Men need 400 mg of magnesium. “Most of our fruits and vegetables are rich enough to meet our daily requirements. Only those with specific medical conditions that make them deficient need magnesium supplements,” says Dr Guru Prasad.