Magnesium Supplementation for Restless Legs Syndrome
Magnesium supplementation is NOT recommended for restless legs syndrome, as there is insufficient evidence to support its effectiveness. 1
Why Magnesium Is Not Recommended
A systematic review specifically examining magnesium supplementation for RLS found only one randomized placebo-controlled trial, which did not demonstrate a significant treatment effect (though it may have been underpowered). 1
After quality appraisal of all available evidence—including the single RCT, three case series, and four case studies—reviewers were unable to conclude that magnesium is effective for RLS or identify which patient groups might benefit. 1
The 2025 American Academy of Sleep Medicine clinical practice guideline for RLS treatment does not include magnesium as a recommended therapy, notably absent from their comprehensive list of evaluated treatments. 2, 3
What You Should Use Instead
First-Line Treatment: Alpha-2-Delta Ligands
The American Academy of Sleep Medicine strongly recommends gabapentin, gabapentin enacarbil, or pregabalin as first-line therapy for RLS (strong recommendation, moderate certainty of evidence). 2, 3
These medications are preferred over dopaminergic agents because they avoid the augmentation phenomenon—a paradoxical worsening of symptoms with long-term use. 3
Address Iron Deficiency First
Check serum ferritin and transferrin saturation in all patients with clinically significant RLS, ideally in the morning after avoiding iron supplements for at least 24 hours. 3
Supplement with oral ferrous sulfate if ferritin ≤75 ng/mL or transferrin saturation <20% (conditional recommendation, moderate certainty). 3
For patients not responding to oral iron, IV ferric carboxymaltose is strongly recommended (strong recommendation, moderate certainty). 3
This iron threshold is higher than general population guidelines because brain iron deficiency plays a key role in RLS pathophysiology, even when serum iron appears normal. 3
Common Pitfall to Avoid
Magnesium is commonly recommended for leg cramps, which may explain why it's often suggested anecdotally for RLS despite lack of evidence. 1
Do not confuse leg cramps with RLS—they are distinct conditions requiring different treatments. 2
Up to 65% of RLS patients use alternative practices for symptom relief, but this does not validate their effectiveness. 4