A small preliminary clinical study of 24 people with fibromyalgia found that a proprietary tablet containing both malic acid and magnesium improved pain and tenderness associated with fibromyalgia when taken for at least 2 months. Other studies suggest the combination of calcium and magnesium may be helpful for some people with fibromyalgia.

However, a review article evaluating a number of studies found that magnesium with malic acid offered no pain relief. More studies are needed.