Fibromyalgia, a widespread chronic pain disorder, imposes a multitude of hardships on patients and their communities. Supplements, specifically magnesium supplements, have been widely used by fibromyalgia patients in an attempt to control their symptoms. The aim of this work is to investigate if the widespread use of magnesium in fibromyalgia is supported by evidence in the literature. This review provides a layout of the studies examining the correlation between body magnesium levels and fibromyalgia. Furthermore, it elaborates on the trials testing the effectiveness of magnesium in treating different clinical parameters of fibromyalgia.