Miller AC, et al. - In this systematic review, researchers examined whether intravenous magnesium sulfate (Intervention) is more efficacious than placebo, corticosteroids, dopamine antagonists, ergot alkaloids, non-steroidal anti-inflammatory drugs, triptans, or usual care in providing pain relief, in lowering rate of recurrence at 24 hours, in lowering requirements for rescue analgesia, and lessening adverse medication effects (Outcomes) among patients with non-traumatic headaches (Population). Analysis of 7 randomized clinical trials with 545 participants with treated migraine headaches (n = 6) and benign non-traumatic headaches (n = 1) were included. Magnesium sulfate vs comparators led to an improvement in pain intensity at 60-120 minutes, but not at earlier time points. Conflicting results for the endpoint of pain reduction by 50% were observed as 3 studies reported that with magnesium sulfate, headache was improved, unchanged, and less. In one study, and in the migraine with aura (MA) subgroup in another, magnesium sulfate was reported resulting in improved complete pain relief. One study, and the MA subgroup in another study displayed improvement in the need for rescue analgesia at any point in correlation with magnesium sulfate. Although no firm conclusion was not made regarding the efficacy or advantage of intravenous magnesium sulfate in treating acute non-traumatic headaches, the current evidence intimates its possible benefits in pain control beyond 1 hour, aura duration, and need for rescue analgesia.