Mustard Plaster/Poultice for Blood Circulation

Research suggests that mustard plasters may influence blood circulation through mechanisms such as cutaneous vasodilation and possible reflex effects on deeper vascular structures, though the available evidence base is quite limited. The two studies identified include a 1962 investigation that tentatively explored a reflex relationship between skin stimulation via mustard poultice and renal plasma flow, and a small single-group pre-post study of 40 older adults with osteoarthritis that reported significant reductions in knee pain following mustard plaster application, with circulatory effects implied rather than directly measured. Both studies directionally support the notion that mustard plasters may produce physiologically meaningful local and possibly systemic circulatory responses, but neither study design allows for confident causal conclusions, as one lacked a full accessible abstract and the other lacked a control group. Overall, the current research is preliminary and methodologically limited, and stronger study designs such as randomized controlled trials would be needed to draw reliable conclusions about mustard plasters and blood circulation.