Over-the-counter muscle and joint pain relievers may cause chemical burns in rare cases, U.S. health regulators warned on Thursday.
Products that contain menthol, methyl salicylate, or capsaicin — including major brands such as Johnson & Johnson's Bengay, Sanofi's Icy Hot, Capzasin and Flexall, and Rohto Pharmaceutical Co's Mentholatum — were found to cause first- to third-degree burns.
"These products should not cause pain or skin damage. However, there have been rare cases of serious burns following their use," the U.S. Food and Drug Administration said in a statement, adding that some burns had led to hospitalization.
Second- and third-degree burns occurred with the use of products that had menthol as the single active ingredient.
Products containing both menthol and methyl salicylate, in concentrations greater than 3 percent menthol and 10 percent methyl salicylate, also caused severe burns, the agency added.
Over the years, the FDA identified 43 cases of burns related to these products. However, current FDA guidelines do not require these muscle and joint pain products to carry a warning on their label about the burns.