Doctors Weigh In on Jessica Biel’s 20-Pound Epsom Salt Bath

It’s no secret that celebrities spend a lot of time preparing for the Met Gala, whether it’s going through hair and makeup trials or eating a specialized diet. Jessica Biel just shared what she did to get ready for this year’s Met Gala, and it’s definitely…unusual.

“I know some people like to party before the Met ball and party all weekend and all the things, and I have total respect for that,” the 42-year-old shared while wearing a white fluffy robe in a TikTok video. “This is what I do to get ready for the Met ball,” she continued, before counting bags of Dr. Teal’s Pure Epsom Salt perched on the side of a tub.

“Twenty pounds of Epsom salt in a bath,” she said, before dumping the bags into a bath. “With water as hot as you can take it. Thirty-minute soak [the] night before,” she said. “Drink tons of water, then and off to bed early.”

The comments of Biel’s video were packed with messages from people who wondered whether this was safe — and why she even did it in the first place. “Genuine question here: What’s the purpose of this?” one person wrote. “I once panicked because I used five cups instead of the recommended four,” another said. “Wow, that’s a lot of salt!” someone else chimed in.

Epsom salt baths are typically used to lower pain and inflammation, but it’s fair to wonder about things like skin irritation and dehydration if you’re surrounding yourself with that much salt. Before you run yourself a bath, we tapped three doctors to weigh in Biel’s practice — and whether or not it’s actually safe.

Is Bathing in 20 Pounds of Epsom Salt Safe?

Epsom salt is a naturally-occurring mineral salt that’s a compound of magnesium and sulfate, per the Cleveland Clinic. There are no definitive studies to support this, but fans swear that Epsom salt baths allow the magnesium and sulfate to be absorbed into your body through your skin. According to claims, Epsom salt baths can help with muscle pain, bloat, and even stress levels.

But most people recommend using much, much less Epsom salt than 20 pounds. “I would not recommend using 20 pounds of Epsom salt— that seems a bit excessive,” says Ife J. Rodney, MD, dermatologist and founding director of Eternal Dermatology + Aesthetics.

Gary Goldenberg, MD, a board-certified dermatologist practicing in New York City, also used the word “excessive” to describe Biel’s practice.

That said, it’s possible to bathe in that much Epsom salt and feel fine, Dr. Rodney tells PS. There is a low risk of getting sick from bathing in this much Epsom salt “unless you have sensitive skin and are prone to rashes,” says women’s health expert Jennifer Wider, MD (more on this later!).

How Much Epsom Salt Is Too Much?

There’s no hard and fast science on this, but the directions for Dr. Teal’s Pure Epsom Salt recommend pouring “at least two cups” of Epsom salts under warm running bath water and soaking for 20 minutes to relieve sore muscles.

“Two cups in a bath full of water is ideal,” Dr. Rodney says. “I don’t recommend higher than this.”

What Are the Potential Benefits of Epsom Salt?

Again, it’s not entirely clear how effective Epsom salt is, but some doctors will recommend Epsom salt baths to help with a range of things, including to ease muscle soreness, tamp down on bloat, and pamper skin.

“Epsom salt is magnesium and sulfate, which has been shown to ease inflammation and soothe dry, rough skin,” Dr. Rodney says. “Anybody with rough skin, dryness, or an inflammatory skin condition like psoriasis may benefit from this.”

Dr. Goldenberg agrees. “Epsom salt can help moisturize the skin and help smooth the skin,” he says. It may also help you chill out. “People have taken Epsom salt baths for hundreds of years as a means of relaxation,” Wider says.

What Are the Risks of Epsom Salt?

When used as directed, Dr. Rodney says there aren’t many risks associated with taking an Epsom salt bath. But, if you have it in excessive amounts, it could bother your skin. “If you’re soaking in such a high salt concentration for a long period of time, it could cause a rash and irritation,” she says.

Soaking in a high concentration of Epsom salt could also “affect the fluid balance in your body,” potentially leading to dehydration, Dr. Rodney says. If you ingested high amounts of Epsom salts — which Biel didn’t do — you would be at risk of diarrhea, dizziness, and an irregular heartbeat, Dr. Wider tells PS.

While doctors say you’re just fine to have a bath with two or so cups of Epsom salts, they don’t recommend taking it to the same extreme as Biel. As with most things in life, it’s best to enjoy Epsom salt in moderation.

Korin Miller is a writer specializing in general wellness, health, and lifestyle trends. Her work has appeared in Women’s Health, Self, Health, Forbes, and more.