But have you heard of magnesium bath flakes? 

Dr. Tara Swart, a leading neuroscientist and author of The Source: Open Your Mind, Change Your Life, swears by her weekly baths with a sprinkle of magnesium flakes. 

Magnesium is a highly recommended supplement for healthy aging because natural levels decrease with age. But a capsule isn’t the only way to increase your magnesium intake. At least one study—looking at the effects of soaking in the Dead Sea, which has a record-high magnesium salt content—has shown magnesium bathing can reduce inflammation and joint pain. And it turns out that you can emulate some of those healing effects at home. 

“I can really tell if I’ve gone for a bit too long without doing it,” Swart, who bathes in the mineral three to five days a week for 15 minutes at a time, tells Fortune.

What are the benefits of magnesium? 

Magnesium is an essential mineral found in many foods, such as green leafy vegetables, seeds, seafood, milk, and yogurt. The mineral protects the body against cardiovascular disease, regulates mood, improves immune health, and plays a vital role in enzyme function. “It underlies about 300 processes in the body, including sleep and mood,” Swart says. A magnesium deficiency can lead to a host of chronic conditions and put people at risk for diabetes. 

Magnesium plays a vital role in brain health too. 

“People who are low in magnesium tend to have higher depression,” Kara Burnstine, registered dietician and nutrition educator at Pritikin Longevity Center, previously told Fortune. The mineral also helps with strong teeth, bones, and muscles, Michelle Schoffro Cook, PhD, holistic nutritionist and author of Super-Powered Immunity, previously told Fortune. 

What’s more, experts have touted magnesium for its cortisol-lowering effects, which can help decrease stress and promote optimal sleep quality. 

Despite its many benefits, many people are not getting enough of the mineral. “It helps us to cope with stress, but it also gets used up when we’re stressed,” Swart says. “A little bit like if you’re training for a marathon and you would take extra protein, you actually need to supplement magnesium because you can’t eat enough nuts and seeds and leafy greens to replace it at the rate that it’s getting used up when you’re stressed.”

The recommended dietary allowance for magnesium is between 400 and 420 milligrams for men and between 310 and 320 milligrams for women. Pregnant women are also advised to increase their magnetism consumption because a deficiency can affect fetal growth and may lead to pregnancy complications.

Magnesium supplements  

Bethany M. Doerfler, a clinical research dietitian at Northwestern Medicine Digestive Health Center, says eating a steady stream of magnesium-rich foods is the best way to increase your intake, along with decreasing stress and not losing it to begin with. 

But for people who suspect a magnesium deficiency or who need a laxative due to constipation, oral supplementation may be required. First, it’s essential to consult with your doctor; while it’s hard to get too much of the mineral, excess magnesium supplementation may lead to an irregular heart rhythm. 

Magnesium flakes and Epsom salts

For those who are not using magnesium supplementation as a laxative and need to increase their intake, oral supplements may not be as effectively absorbed by the body, says Julia Zumpano, a registered dietitian with the Cleveland Clinic Center for Human Nutrition. She adds that the oral supplement can move too quickly through the bloodstream, which is why Swart prefers the flakes. 

“Transdermal [through the skin] has been noted to have better absorption,” she says. “It is not passed through the GI tract. Therefore, it is not likely to have a laxative effect.” Magnesium flakes, while similar to salts, are made up of the mineral plus chloride and may be absorbed even faster in the bathwater. 

However, more long-term research is needed to recommend transdermal magnesium as an official treatment. A 2015 study found transdermal magnesium sprays may help patients who have fibromyalgia. Further, a study over two decades ago concluded that transdermal magnesium could help replenish the mineral in those with a magnesium deficiency faster than an oral supplement. However, per a 2017 paper of existing research published in Nutrients, a complete description of that study is no longer available. This more recent analysis found that while transdermal and topical magnesium—particularly magnesium-containing sprays, oils, and magnesium sulfate (Epsom salts)—may be able to be absorbed by the skin faster than oral supplements, the research is preliminary and not sufficiently vetted or long-term. Doerfler echoes this sentiment and says magnesium can be absorbed in the skin, but there is not enough evidence to call it the superior method. 

How to bathe in magnesium flakes

Still, bathing in the proper dosage of magnesium flakes for a short time poses no adverse risks and likely won’t irritate the skin, Doerfler says. She adds that the flakes “can improve both absorption as well as relieve muscle soreness and improve sleep if you are low in magnesium intake.”

Ultimately, bathing in magnesium flakes or salts, which cost between $20 and $30, can offer a double bonus: As you soak up the healing properties of the mineral, you’ll also be promoting relaxation. Warm baths help release oxytocin, which can mimic a warm hug, Swart says—a great way to reduce stress and calm the nervous system.

If you’re interested in trying out the approach, Swart suggests using the product label’s recommended amount—typically one to three cups—of the flakes of your choosing for a 15-minute bath a few times a week to feel the benefits.