Mint is a popular herb that is known for its refreshing and invigorating flavor. One of the reasons mint is so refreshing is because it has the ability to create a cooling sensation in the mouth. This effect is caused by the chemical compound menthol, which is found in mint plants.

Menthol activates a specific type of receptor in the mouth and throat called the TRPM8 receptor. When menthol binds to these receptors, it causes a cooling sensation in the mouth. This effect is similar to the way that cold temperatures can cause a cooling sensation in the mouth.

In addition to activating the TRPM8 receptor, menthol also has anesthetic properties. It can numb the mouth and throat, which can help to reduce the sensation of pain or discomfort. This is why mint is often used in mouthwashes and throat lozenges to soothe soreness and provide relief.

The cooling sensation caused by menthol can be intensified by the presence of other compounds, such as eucalyptol or menthone. These compounds can also contribute to the refreshing and invigorating flavor of mint.

Overall, the reason mint makes your mouth cold is due to the presence of menthol, which activates the TRPM8 receptor and causes a cooling sensation in the mouth. This effect, along with the anesthetic properties of menthol, is what makes mint such a refreshing and invigorating herb.