Is Magnesium useful for allergy?

Whether magnesium is useful for allergies is not clearly supported by current evidence. Mechanistically, magnesium can inhibit mast cell degranulation and histamine release, and it has bronchodilatory effects, which could theoretically benefit allergic asthma or rhinitis. Some small clinical trials suggest modest symptom relief (e.g., reduced itching or nasal congestion) with oral or intravenous magnesium. However, the evidence is weak to moderate; large, well-controlled studies are lacking, and observed effects may be due to general anti-inflammatory or stress-reducing properties rather than allergy-specific mechanisms. Bioavailability varies by magnesium form (e.g., citrate, glycinate). Correcting a deficiency is advisable, but routine supplementation for allergy treatment is not recommended. Magnesium is not a substitute for standard allergy medications like antihistamines or epinephrine in emergencies. Evidence rating: mechanistic/unclear. No relevant genetic variants from the provided context allow personalized guidance.