Onion Poultice for Cough Relief

Research suggests that onion and its bioactive compounds, particularly quercetin and thiosulphinates, have demonstrated anti-inflammatory, antimicrobial, and respiratory-relevant properties in the scientific literature, with two narrative reviews cataloguing a broad range of biological activities observed across preclinical and clinical studies. Studies indicate that these reviews, while supportive in tone, are narrative in nature and do not establish definitive proof of therapeutic benefit from onion poultice specifically for cough relief in humans. The most direct clinical evidence comes from a single randomized, double-blind, placebo-controlled trial examining orally administered onion peel extract, which found largely non-significant results for immune markers overall, though a subgroup of participants with higher respiratory symptom burdens did show measurable improvements in NK cell activity, and participants also reported reduced hoarseness compared to placebo. Taken together, the available evidence is preliminary and indirect with respect to topical onion poultice for cough, relying on general pharmacological properties of onion constituents rather than trials testing the poultice application itself, so stronger and more targeted research would be needed before firm conclusions can be drawn.