Menthol, a compound in mint, acts on the same sensory receptors as cold temperatures but in a different way.

Because of that, menthol increases the effect of cold, making substances feel cooler than they really are.

The findings could lead to more effective treatments for conditions like pain, congestion, and dry eye.

Cool mint mouthwash, winterfresh toothpaste, polar mint gum: many breath-freshening products capitalize on the cooling power of mint. But why exactly does mint make our mouths feel cold?

Our skin, mouths, and eyes are studded with temperature-detecting sensory nerves. They’re key to our survival, helping us to identify which environments, foods, and fluids are safe for our bodies.

A sensory receptor called TRPM8 (transient receptor potential melastatin 8) activates in response to cool stimuli.

When the temperature of the air that touches our skin or the food we put in our mouths falls between 10° and 28°C (46° and 82°F), the TRPM8 receptor opens up, allowing ions to move into the attached nerve cell. This movement sends a message along the nerve fiber to the brain, which translates it into a perception of coolness.

“Imagine TRPM8 as a microscopic thermometer inside your body,” says Hyuk-Joon Lee, a postdoctoral fellow in biochemistry in the lab of Prof. Seok-Yong Lee at Duke University. “It’s the primary sensor that tells your brain when it’s cold.”

Mint’s effect on the nervous system

Mint plants contain an aromatic compound called menthol. It occurs in particularly high concentrations in spearmint and peppermint, and it seems to have evolved as a natural defense mechanism for the herbs, creating an intense cooling sensation in the mouth that deters predators from eating them.

Scientists theorized as early as the 1950s that menthol somehow activates the same nerve receptors as cold temperatures, but they weren’t able to show exactly how that happens until now.

Using cryo-electron microscopy, a technique where molecules are frozen then imaged with an electron beam, Lee and his colleagues discovered that cold temperatures and menthol both activate TRPM8 receptors, but in distinctly different ways.

Cold acts directly on what’s called the “pore” of the receptor, stimulating it to open so that ions can pass through. Menthol binds to a different part of TRPM8, changing the shape of the receptor in a way that forces the pore open.

“Menthol is like a trick,” Lee explains. “It attaches to a specific part of the channel and triggers it to open, just like cold temperature would. So, even though menthol isn’t actually freezing anything, your body gets the same signal as if it were touching ice."

“We’ve known for a long time that this happens, but we didn’t know how. Now we can see it.”

The findings also shed light on why menthol makes other substances feel colder than they really are.

Have you ever taken a deep breath after sucking on a mint and noticed the air felt cooler than before? Or been surprised by how icy water tastes after you’ve just brushed your teeth with mint toothpaste?

Because cool temperatures and menthol activate the TRPM8 receptor in different ways, they compound each other’s effects, making the sensation of coolness even more intense.

The team presented their findings at the 70th Biophysical Society Annual Meeting in San Francisco, Feb. 21-25, 2026.

Unlocking potential for medical advances

A better understanding of how menthol acts on the body could lead to more effective medical treatments.

Menthol is already used in topical ointments to relieve pain from muscle soreness, arthritis, and migraines. It works both because its cooling sensation distracts the brain from pain and because, at high doses, it activates and desensitizes pain receptors.

The compound is also a common ingredient in decongestants and lozenges. Menthol numbs the throat and makes it feel easier to breathe by cooling the airways.

As we gain more insight into menthol’s effect on the nervous system, it’s being put to use in new medications, like eyedrops.

A menthol derivative called acoltremon was recently approved by the FDA to treat dry eye. The drug relieves irritation and stimulates tear production by activating TRPM8 cold receptors in the eye.

Menthol even shows promise as a sport supplement.

One study demonstrated that runners who used a menthol mouth rinse partway through training felt less hot and, as a result, were able to run faster in a 5-kilometer time trial. Drinking an ice slushie, on the other hand, lowered the runners’ actual body temperature but didn’t help them feel any cooler or run any faster.

Study author Christopher Stevens, Associate Professor of Sport and Exercise Science at Southern Cross University, believes that’s because the psychological effects of menthol are as powerful as its physical effects.

“How hot you feel,” he observes, “may be more important than how hot you are.”

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