Mustard Plaster/Poultice for Joint Pain Relief

Research suggests that mustard-derived compounds may offer some benefit for joint pain relief, though the current evidence base is limited in both size and study design. A small single-group clinical study in older adults with knee osteoarthritis found meaningful reductions in self-reported pain and functional limitations after seven days of mustard plaster application, but the absence of a control group makes it difficult to rule out placebo effects or natural improvement over time. Supporting this, two preclinical studies — one in a mouse model of rheumatoid arthritis and one in cell cultures — found that allyl isothiocyanate, an active compound in mustard, reduced inflammatory signaling through several biological pathways, including suppression of mast cell activity and key inflammatory proteins. Taken together, the available research is preliminary and largely based on animal and laboratory models, meaning findings cannot yet be directly applied to human use, and well-controlled clinical trials would be needed to draw firmer conclusions about efficacy and safety.