Sometimes we come across a remedy or recommendation that, at first blush, doesn’t seem to make any sense. That certainly was the response from many of our readers when we wrote about putting soap under your bottom sheet to ease restless legs. Here is one typical response from 2010:
Q. Being from a science/medical background, it frustrates and irritates me to no end that a silly nonsense remedy, putting soap under the bottom sheet, actually WORKS. I’ve dealt with severe restless legs syndrome (RLS) for years. During the worst phases, I got NO sleep four or five nights a week because I just couldn’t stop moving my legs.
Desperation drove me to try the soap about six months ago. I haven’t had a bad night since. AT ALL.
I’ll actually have RLS symptoms in the living room watching television, and they abate as soon as I go to bed where my soap is. This actually makes me a little bit mad, because it makes NO SENSE! There’s no rational reason why this should work, but it does!
A. We can’t disagree with you. Putting soap under your bottom sheet makes no sense to us either. Nevertheless, hundreds of readers report benefit. Of course, others tell us it is worthless. But we think such an inexpensive, low-risk approach is worth a try.
Does Soap Under Your Bottom Sheet Really Help?
Many people have written to us about their success with this strategy, but not everyone benefits. And there are a few who wouldn’t believe it even if it were true:
Q. I read your newspaper column about using a bar of soap to curb restless legs. This is a fairy tale.
I do not have restless legs, but I used to wake up in the middle of the night with a charley horse. My heart doctor had recommended a bar of soap but it never helped with the leg cramp.
There Is Actually Some Science Behind This Remedy:
A. We have heard from hundreds of readers that soap under your bottom sheet can prevent leg cramps and even restless legs. It doesn’t work for everyone, but there is some science that supports the use of soap. A skin patch with soap-scented oil eased the pain of fibromyalgia and of menstrual cramps (Ough, Journal of Multidisciplinary Healthcare, Sep. 1, 2008; Ough et al, Journal of Alternative and Complementary Medicine, July 2008).
One possible explanation for the soap effect is the fragrance. A chemist suggested to us that the most popular soaps all seem to have the fragrant compound limonene in their scent.
Another reader reported benefit with fragrance alone:
“Your comment on ‘smell receptors’ in the skin was great. I use my perfume roll on each calf at bedtime. Instead of nightly agony, I’ve only had a leg spasm once since I started. I simply reapplied perfume. What a difference!”
How Does Scent Work?
We don’t know for sure exactly how soap under your bottom sheet can help ease restless legs or muscle cramps, but we suspect that transient receptor potential (TRP) channels are involved. (Limonene activates TRP A1.) You can read more about the effect of these ubiquitous channels on nerves and muscles here, here and here. You may also want to listen to Dr. Bruce Bean explain how TRP channels affect muscle cramps, in Show 1054: The Scientific Explanation for a Weird Remedy.