The latest health craze that’s swept social media: magnesium lotion.
Magnesium is an essential mineral that the body uses for various functions. It’s long been thought to help with sleep when taken as an oral supplement, although there’s little scientific evidence to back up that claim.
Influencers are now promoting magnesium in lotion form as an elixir for better sleep, as well as treating a wide range of problems, including cortisol and insulin imbalances, muscle pain, fibromyalgia, and arthritis.
“Did you know that rubbing magnesium cream on your child’s feet can help with sleep?” asks a woman on TikTok named cottagecalderon, who promises it can help with growing pains and improve mood.
“No more midnight leg cramps,” says a man on the account tap.the.orange.cart. “It works for me and my wife.”
“Hey, guys,” says another TikToker, well over 40, “this magnesium lotion and spray is magic in a bottle.”
The Claim
Enthusiasts claim that magnesium lotion — applied specifically to the feet — can improve sleep. Many also argue it can be applied all over the body to remedy a variety of other health problems.
People are buying the idea, literally. A market research group estimated that the 2024 market for topical magnesium was over $400 million.
The Evidence
There’s little proof that magnesium can be absorbed through the skin.
“The problem with that is that the skin is a barrier, not a sponge,” says Nicholas Theodosakis, dermatologist and researcher at Harvard University.
Most medications are better administered orally, allowing quick absorption into the bloodstream. Few substances are well-suited for skin absorption, he says. Transdermal patches are often used for medications that need to be absorbed slowly over time.
There’s no evidence that magnesium falls into that category.
Theodosakis theorizes that any benefits from magnesium lotion likely come from the massage used to apply it or the lotion’s moisturizing ingredients.
“You apply a cream or lotion or ointment containing some active ingredient, and yes, your skin looks better than in places where you didn’t apply it,” says Theodosakis. “But that’s because the cream itself promotes skin health. Anything in a cream or ointment base is automatically good for the skin.”
The Nuance
Despite the lack of evidence, at least one doctor says if magnesium lotion is working for you — go ahead. “I think the risks of applying magnesium to the skin are probably extremely small,” says Dr. John Winkelman, Harvard sleep specialist.
He says he had at least one patient who reported using “magnesium butter” for sleep. (“I thought you put that on bread, but no, actually you rub it on your legs,” says Winkelman.) “She said the magnesium butter was helping.”
Winkelman says that, especially with sleep issues, the placebo effect can be powerful — and he’s not one to discourage safe remedies that work for his patients.
That said, Winkelman doesn’t plan to recommend it anytime soon.
The Food and Drug Administration doesn’t approve supplements and related products based on safety and efficacy data the same way it does for drugs, so there’s no guarantee these products deliver on their promises.
For some of the sleep conditions magnesium lotion supposedly treats, says Winkelman, there are proven medical treatments. Restless legs syndrome, for example — which some influencers claim is relieved by magnesium lotion — has real, tested medical therapies.
“I really don’t think it’s fair to recommend things I don’t believe have been proven effective,” says Winkelman. “I’m a big advocate for scientific evidence.”
The Bottom Line
While there’s no proof that magnesium lotion promotes sleep or treats medical issues, experts including dermatologist Nicholas Theodosakis agree it probably won’t hurt — except, he says, “your wallet.”
He notes that, as a dermatologist, he sees lots of health fads. “I think it’s just the nature of skin,” he says. “It’s highly linked to emotional well-being, psychology, and culture. Plus, you have a lot of it.”
Source: npr.org by Katia Riddle