Marseille Soap for Leg Cramps Thanks to French Grandmothers

Have you ever been bothered by sudden muscle cramps that wake you in the middle of the night? Long ago, a reader suggested putting a bar of soap under the bottom sheet of the bed to prevent nocturnal leg cramps. When we tried it, we found it helped a lot. We did not know that it may have originated in Marseille, France. But that’s what one reader recounted. Who knew that French grandmothers swear by soap for leg cramps?

A Discovery in Marseille:

Q. I just want to let you know that I was in Marseille recently and saw some soap labeled “for cramps” in French. I spoke with the store owner and he said that Marseille soap is a well-known alleviator of leg cramps when placed in the bed.

This was normal Marseille soap (72 percent oil), but instead of being sold in cubes it was sold in a flat version so it would be more comfortable under the sheets. When I asked him what he thought was the effective ingredient, he said it was potassium. I thought you might find this interesting since you have often written about the soap remedy.

A. Thanks for alerting us to the reputation of Marseille soap.

One manufacturer of flat Marseille soap “loaves” has put this on its website:

“Marseille Soap were been used by our grandmothers, who put at the bottom of their beds to soothe the discomfort of leg cramps…” [this is how it was described on the website]

We were unaware that French grandmothers have been using soap for leg cramps for decades, if not longer. Most health professionals are skeptical about the value of soap in bed, but it is surprising how often the old wives turn out to be right.

Will Soap in Bed Aid Insomnia?

Q. I had heard for years about putting soap in bed as a remedy for leg cramps. However, I hadn’t needed it until recently.

Not long ago, I started having insomnia several nights a week, along with foot and leg cramps. So I got a bar of lavender soap and put it in bed near my feet. It made my sheets smell heavenly.

I have not had even one little foot or leg cramp since putting the soap there. And my insomnia is now non-existent! I wake up well-rested. I don’t know why it works, but it really does!

A. Lavender (Lavandula angustifolia) has been used in aromatherapy for centuries, if not millennia. A review in Evidence-Based Complementary and Alternative Medicine (March 14, 2013) reinforces the use of this essential oil to overcome insomnia. To be sure, some other readers have also enjoyed this benefit. In addition, an analysis of 11 studies found that breathing the aroma of lavender can help ease anxiety and its symptoms (Healthcare, Nov. 17, 2023).

Soap for Leg Cramps-A People’s Pharmacy Staple:

We first heard about putting soap under the bottom sheet to ease leg cramps over a decade ago:

“For years, I have been plagued with terrible leg cramps. Neither quinine pills nor tonic water helped much and I often spent half the night up with cramps.

“I read a syndicated column in the paper, and I love the fact that the doctor is not afraid to pass on a few folk remedies. One suggestion sent to him by a reader was to put a bar of soap (not Dove or Dial) beneath the bottom bed sheet.

“Under the cover of darkness (so my husband, who is an M.D., wouldn’t see), I slipped a bar of soap under the sheet on my side of the bed. For two nights I continued to have mild leg cramps but by the third night they were gone. I have not had them since.”

Some Research Behind the Relief:

Most physicians pooh-pooh the idea that of soap for leg cramps. They chalk it up to the placebo effect.

An anesthesiologist (now retired) was fascinated enough to actually conduct a couple of experiments and publish his results. Dr. Yon Doo Ough and his colleagues crushed Ivory Soap (a brand that has frequently been touted as effective by our readers). They created skin patches with the crushed soap and placed it over muscle cramps. They noted positive results for women with menstrual cramps (Journal of Alternative and Complementary Medicine, July, 2008).

Dr. Ough believed that it was the scent of the Ivory soap that might be having a positive impact on cramps. He then tested soap-scented oil (SSO) in a skin patch for people complaining of fibromyalgia. He concluded that: “the SSO skin patch consistently and adequately relieved muscular pain.” published in the Journal of Multidisciplinary Healthcare, Sept. 2008.

Here are some of Dr. Ough’s case reports:

Case report 1

“The patient is a 56-year-old female with an 11-year history of fibromyalgia. She described numerous, widespread tender points along her upper arms, shoulders and back, and her condition has diminished her quality of life. She has received treatment from her primary care physician, rheumatologist, psychiatrist, physical therapist and chiropractor. As a sleep aid, she was taking duloxetine hydrochloride (Cymbalta) 20 mg and amitriptyline (Elavil) 25 mg.

“After application of the SSO skin patch, the patient reported a pain score decrease from 8-10 to 2-3.”

Case report 3

“The patient is a 67-year-old female with a 45-year history of fibromyalgia. She spent most of her time indoors, usually in bed, due to her intense pain (rated 9-10). She also reports difficulty sleeping, in spite of pharmacological sleeping aids.

“Within 20 minutes of SSO skin patch application, she reported nearly complete pain relief (rated 1-3) and improved quality of life.”

Dr. Ough concluded his paper:

“I hypothesize that the active ingredient in the SSO skin patch is the scent itself. This would represent a new and unique method of medicinal delivery, because the scent is seemingly absorbed through the skin and not via the olfactory system.

“From these results, I conclude that the SSO skin patch is a safe and effective topical treatment for the pain of fibromyalgia.”

Bottom Line on Soap for Leg Cramps:

We are the first to admit that Dr. Ough’s interesting reports do not rise to the level of large, randomized, double-blind, placebo-controlled trials. On the other hand, soap is cheap, low risk and even if it doesn’t work you can always shower with it. No drug company is likely to spend money on scientific studies to prove soap does or does not work: too cheap and not patentable.

Flat Marseille Soap vs People’s Pharmacy Bed Soap:

We were intrigued to learn that the Marseille soap for leg cramps our reader discovered in France was sold in a flat version to make it more comfortable in bed. Terry came up with this same idea several years ago. That is why we developed The People’s Pharmacy Bed Soap. It is larger and flatter than regular bath soap. It also has a pleasant lavender fragrance, which could help people fall asleep. Here is a link to the entry in the store.