The Science Behind Why Sichuan Peppers Make Your Mouth Feel Numb

We heat lovers like to revel in our affinity for spicy foods, which can say a lot about you as a person. Though Sichuan peppers aren't considered spicy themselves, they can intensify the level of spice you perceive. Even if you love all things fiery, this one might throw you for a loop.  

Sichuan peppers cause a numbing sensation known as málà, which means "numb" and "spicy" in Chinese. They are often paired with chili peppers and are a hallmark of dishes like mapo tofu, dan dan noodles, and Fu Qi Fei Pian. Though Sichuan peppers don't have the intense heat of chili peppers, their tingly, citrusy quality makes the spice more pronounced and adds complexity to hot flavors.

It's not like biting into a jalapeño where you get that straight-up burn. Sichuan peppercorns don't contain capsaicin (the stuff that sets your mouth on fire), which is found in chili peppers. Instead, these peppercorns contain hydroxy-alpha-sanshool, a compound that plays a weird little trick on your nerves and makes your brain think that your mouth is vibrating. Of course, your tongue isn't actually buzzing, but your nerves are firing in a way that makes it feel like it is.

Researchers were able to discover that sanshool makes your nerves fire at about 50 Hertz – the same frequency as a low electrical current or the low vibration of a phone. Some people even compare it to the sensation of licking a 9-volt battery (not recommended, by the way). Speaking from experience, that numb feeling usually starts off mild and builds up the more you eat. Surprisingly, it actually makes spicy food more tolerable because the numbing effect counteracts the burn from chili peppers, which is why Sichuan cuisine loves to mix the two.

So, why does a pepper do something so strange to your mouth? Like most plants with strong flavors, it's probably an evolutionary defense mechanism. Just like chili peppers use spiciness to keep predators away, Sichuan peppers might have developed this numbing effect to make themselves taste unappealing. But, instead of avoiding them, humans leaned in and decided they were delicious. Plus, a lot of people enjoy that "high" feeling you get when you eat spicy foods.

Outside of China, Sichuan pepper is starting to get more attention in modern cooking and across various cuisines. Since the pepper can change how we perceive other flavors, adventurous chefs are playing around with it in everything from spicy cocktails to tongue-buzzing desserts. Sichuan pepper also has the potential to be used for pain relief since it interacts with the nervous system in such a unique way.

So, if you've ever wondered why your tongue feels like it's buzzing after eating Sichuan food, now you know — it's basically a tiny, edible science experiment happening right in your mouth. Some people love the unique sensation, whereas others find it totally undesirable or even alarming. So, to each his own but, whether you hate it or love it, there's nothing else quite like Sichuan pepper. You may find yourself going back for more, numb tongue and all.