Biofreeze works primarily through menthol, its active ingredient, which triggers cold-sensing receptors on your skin’s nerve fibers. This creates a cooling sensation that competes with and reduces pain signals traveling to your brain. The effect is similar to applying ice, but the mechanism involves a more complex chain of neurological events than simple cold exposure.
The Cooling Sensation Is a Neurological Trick
When you rub Biofreeze onto sore muscles or an aching joint, the menthol in the gel activates a specific receptor on your sensory nerve endings called TRPM8. This is the same receptor that fires when your skin is exposed to cool temperatures between about 46°F and 82°F. Menthol essentially mimics cold, convincing your nervous system that the area is being cooled even though no actual temperature change has occurred. This is why Biofreeze feels intensely cold on the skin without lowering tissue temperature the way an ice pack does.
That cooling signal does more than just feel pleasant. It activates what’s known as “gate control theory,” a well-established model of how the nervous system prioritizes sensory information. Your spinal cord can only process so many signals at once. When a flood of cooling input arrives from the menthol, it essentially crowds out pain signals trying to travel the same pathway to your brain. The “gate” closes on pain and opens for the cooling sensation instead.
Menthol Also Triggers Your Body’s Own Painkillers
The pain relief from Biofreeze goes beyond just competing signals. Research published through the National Institutes of Health found that menthol’s activation of TRPM8 receptors also triggers endogenous opioid pathways, your body’s built-in painkilling system. When researchers blocked those opioid pathways with a drug called naloxone, menthol’s pain-relieving effect was significantly diminished. This means part of the relief you feel comes from your own body releasing natural pain-suppressing chemicals in response to the menthol stimulus, not just from the cooling distraction.
What Happens to Blood Flow
Menthol has a nuanced effect on circulation. In the area where you apply it directly, menthol tends to increase blood flow through a combination of nitric oxide release and sensory nerve responses. This localized boost in circulation can help with the healing process by delivering more oxygen and nutrients to damaged tissue. In surrounding areas that aren’t directly treated, menthol can actually decrease blood flow, likely because the body interprets the cooling signal as a reason to conserve heat and constricts blood vessels in response. This dual effect is part of what makes menthol behave differently from a simple ice pack.
How Biofreeze Compares to Ice
A randomized study from the University of San Diego compared Biofreeze directly against ice packs in 51 people with acute neck pain. Both treatments significantly reduced pain, but the results weren’t equal. Participants who used Biofreeze saw their pain scores drop from 6.24 to 3.65 on a 10-point scale, while the ice pack group only dropped from 6.31 to 5.00. That’s roughly twice the pain reduction with Biofreeze. Nine out of ten participants also reported that Biofreeze’s effects lasted longer than ice, and patients preferred it over cold packs by a ratio of 8 to 1.
This doesn’t mean Biofreeze is universally better than ice for every situation. Ice packs physically lower tissue temperature and reduce swelling through direct cooling, which matters more for acute injuries with significant inflammation. Biofreeze is more practical for ongoing muscle or joint pain where convenience and duration of relief are priorities.
What’s Actually in the Formula
The FDA classifies Biofreeze as an over-the-counter external analgesic, specifically a counterirritant. The agency defines counterirritants as topical drugs that stimulate skin receptors to relieve pain in muscles and joints. Menthol is the only active ingredient, present at a concentration within the FDA-approved range of 1.25% to 16%.
The inactive ingredients include aloe, arnica flower extract, green tea leaf extract, camphor, vitamin E, and yerba mate leaf extract, among others. These don’t have the same regulatory burden as the active ingredient and primarily serve as carriers, skin conditioners, or sources of mild anti-inflammatory plant compounds. The camphor likely contributes a small additional warming or tingling sensation. Isopropyl alcohol helps the gel absorb quickly and evaporate, which adds to the initial cooling feel on the skin.
How to Use It Effectively
Biofreeze is approved for adults and children two years and older. You apply a thin layer over the painful area up to four times per day. You don’t need to massage it in deeply; a simple rub to spread it evenly is enough. The cooling sensation typically starts within a minute or two and can last anywhere from one to several hours depending on the formulation (gel, roll-on, spray, or patch) and how much you applied.
Avoid using it on broken skin, open wounds, or near your eyes and mucous membranes. The menthol and alcohol in the formula will cause intense stinging on damaged skin. Don’t combine it with a heating pad or wrap the treated area tightly, as this can intensify the sensation to an uncomfortable or irritating degree. Washing your hands after application prevents accidentally transferring menthol to sensitive areas like your eyes.