The Topical Pain-Relief Research Roundup

There are many ways to relieve pain by placing something on the skin: ice, hot packs, Bengay, Biofreeze, Sombra, etc. Ice and heat have been around for millennia, and research has now revealed many secrets about how they work. Relatively speaking, however, the lotions, sprays, and rubs are the new kids on the block... so do they work?

Let's go to the research!

The main ingredient in most of the lotions on the market is menthol, a byproduct of alcohol that has a cooling effect when applied to the skin. Recent research, surprisingly, indicates that menthol works in two ways: 1) by fooling the brain into thinking about the cold sensation instead of the pain, and 2) actually causing decreased blood flow in the area, probably because the brain was already fooled into thinking the area would cool down the blood.

Major journal articles in the past decade indicate that

- menthol does not appear to cause adverse skin reactions
- menthol appears to target a special, and hitherto-unknown nerve receptor called TRPM8
- menthol appears to actively reduce local blood flow (a very important finding when controlling inflammation is a key target of treatment), similar to the application of ice
- although menthol is slightly less effective than ice in reducing arterial blood flow, patients report less discomfort with menthol than with ice applications
- this study appears to prove that topical menthol causes less discomfort than ice
- menthol appears to cause temporary pain relief even in acute injuries such as muscle strain, although long-term effects were not examined in this study

Topical analgesics such as Biofreeze or Sombra provide limited pain relief and are not designed to fix the root cause of your pain (that's what chiropractic is for!). And I have always preferred ice and heat for topical applications because they are free and easily applied at home. But, that being said... recent research indicates strong support for topical lotions and creams for a variety of acute and chronic pains.