Rubbing a bar of soap on bedsheets may sound unusual, but it is an old-fashioned home remedy that some people use for nighttime leg cramps and restless legs. The tradition has been passed down through generations and remains popular because it is simple, inexpensive, and easy to try before bed.

The method is straightforward. People typically use a dry bar of soap and rub it across the fitted sheet near their legs and feet. Others place the soap underneath the sheet, usually close to their feet. Lavender-scented soaps are sometimes preferred because lavender is commonly associated with relaxation and sleep.

Supporters believe the soap may somehow help calm uncomfortable legs or reduce nighttime cramping, possibly because of its scent, ingredients, or the relaxing effect of the bedtime routine. However, there is currently no strong scientific evidence showing that placing soap in or under bedsheets prevents leg cramps. As the article notes, “personal experiences do not prove that the soap itself is responsible for the improvement.”

The benefit may instead come from comfort and routine. A familiar ritual before sleep can help some people feel more relaxed, which may make it easier to settle down. In that sense, the soap could become a reassuring part of a nighttime routine without directly affecting the muscles.

For people who want to try the tradition, keeping the soap dry and choosing a mild or lightly scented bar may be preferable. Strong fragrances can irritate sensitive skin if the soap comes into direct contact with it. Ultimately, “it is not a scientifically proven treatment for leg cramps or restless legs,” but some people continue the practice because they feel it makes a difference.