Side Effects of Bengay

Another name for methyl salicylate, athletes and fitness enthusiasts alike rely on creams like BenGay to help soothe sore muscles after a tough workout. The topical ointment works by creating a warming sensation, which can help release tight muscles. Before you slather on a generous helping, however, you should know the side effects of using methyl salicylate as a post-workout aid. In some cases, a simple warm compress may be a better bet.

Runner holding a sore hamstring (Image: twinsterphoto/iStock/Getty Images)

Warming and Cooling Sensation

The application of methyl salicylate is to trigger a cooling and warming reaction with your skin, so that's likely the first side effect that you'll notice. The reaction can help reduce pain and swelling of sore muscles, which is why you'll find BenGay and similar creams in the gym bags of many athletes and fitness enthusiasts. Because methyl salicylate can cause a burning sensation, however, it's important you keep it away from sensitive skin, your eyes or mouth.

Allergic Reaction

If you're sensitive to methyl salicylate, you may experience allergic reactions to the application of the cream or gel. A skin reaction, where skin blisters after application, means you should discontinue use immediately. You may also experience a swelling of the tongue, difficulty swallowing or hives. These are the signs of an allergic reaction, so contact your doctor, particularly if it's affecting your breathing.

Possible Overdose

While it may seem implausible, it is possible to overdose on a methyl salicylate-based cream like BenGay. Overdose can occur when a product contains a high amount of methyl salicylate -- BenGay Extra Strength contains 30 percent methyl salicylate -- and is absorbed into the body. While used as directed, it's not dangerous, but when used with devices that speed absorption, such as heating pads or patches, methyl salicylate can become toxic. According to Scienceline, 17-year-old track star Arielle Newman died from a methyl salicylate overdose. While she never used heating pads, she did use the cream while running and the sweating and heat allowed her body to absorb a toxic level of the cream.

Using Methyl Salicylate

The FDA does approve methyl salicylate-based products for the use of sore muscles, but mandates that a warning be placed on any product containing more than 5 percent of the oil of wintergreen-derived ingredient. Choose the product with the least amount of methyl salicylate for your pain. Check the instructions for BenGay carefully before applying and never use it in conjunction with heating pads, a steam room or while exercising vigorously to use the product safely.