Why Does Soap Under the Sheet Lose Its Power?

So many people swear that putting soap under the bottom sheet works to prevent or ease leg cramps that we believe them. This remedy presents a challenge for many health professionals because there is no obvious mechanisms of action. Why, for example, would soap under the sheet lose effectiveness?

Q. I have used soap under the sheet and found that it helps prevent muscle cramps. I have read in your column that the effect wears off after several weeks. Why? Since it isn’t being used for bathing, why would it wear out?

A. There is relatively little scientific study of the anti-cramping effect of soap under the sheet. One theory, however, is that it works by releasing volatile chemicals such as limonene, a natural compound found in the rinds of lemons, limes and oranges. These agents are added to soap for their aroma.

The Science Behind “Bed Soap”:

An anesthesiologist who was intrigued by the reports of soap fighting cramps tested crushed soap against muscle cramps and menstrual cramps (Journal of Alternative and Complementary Medicine, July, 2008). He proceeded to test the scent alone and reported that it relieved muscular pain (Journal of Multidisciplinary Healthcare, Sept., 2008).

The soap releases its fragrance compounds slowly over time. Eventually their concentration diminishes, which may explain why some people report that the soap under the sheet loses its effectiveness after a few months.

When Soap Loses Its Oomph:

Darla said:

“I used the same bar of Jergens for almost a year until it stopped working and my cramps returned full force. I replaced it with a new bar of Irish Spring and my cramps disappeared again.”

FJB from Michigan shared this:

“Soap needs to be replaced every 4 weeks in the bed; Ivory brand works the best. This really does work for getting rid of leg cramps.”

Robert in Juno Beach, FL has a system:

“I have used Ivory bar soap for more than ten years with total success. When slight cramping re-emerges, I cut the bar in half. When that stops working I replace it with a new bar. I keep soap in an air-tight ZIP-LOC bag during daytime. Regardless of what “Medical Authorities” state – Soap prevents leg cramps if used properly.”

Reviews for People’s Pharmacy Bed Soap:

Several years ago we came up with the idea of putting lavender fragrance in soap along with extra limonene. Some studies suggest that lavender fragrance might help people sleep better.

We also thought it would be more comfortable if we made the soap much thinner and slightly bigger than standard bar soap. That way there would be more surface area but it would not create a lump under the bottom sheet. That is how People’s Pharmacy Bed Soap was created.  Here are just a few of the reviews from people who have tried Bed Soap:

Janet in Houston:

“Oh my gosh, I love this soap! From the first night that I put it under the sheets, I have slept better and I no longer have leg/ankle/foot cramps. My husband swears he is sleeping better than he has in years. He had periodic limb movement and it has completely gone away. I am buying this soap for everyone for Christmas!”

Denise in Land O Lakes, FL:

“I have been putting soap under my sheets for over a year now. My ankle cramps have completely subsided. I can tell when the soap is getting old because the cramps start coming back. I was using Irish Spring or Dove soap before; I have just recently started using The People’s Pharmacy soap. So far, so good.

“I like the flat shape of the new soap and it is more fragrant than the Irish Spring or Dove. It’s all about the scent. I don’t have a problem with the soap falling out of the bed because the sheets are tucked in OVER the soap. Mattress pad, then soap, then sheets. Everything stays in place.”

Read more reviews here. Of course not everyone gets benefit from soap under the sheet but you will be amazed at how many people do seem to get relief.

Share your own experience with soap under the sheet in the comment section below.