The challenge with the “cinnamon challenge” is swallowing a tablespoon of cinnamon without vomiting or inhaling it.
This has been a popular meme for a while. Many have failed at it, and then posted a video about how they failed on YouTube.
The challenge started trending in 2006 and spread like wildfire, to the point where thousands of people are trying it. This video gives legit scientific reasons why you shouldn't give in to the dare.
The makers explain that the human mouth only produces 1 liter of saliva per day, of which just about one tablespoon is actually found in the mouth at any given time. Cinnamon is water resistant, as it is just powdered tree bark, so there is no way that it will melt and you will be able to swallow it.
Ingesting cinnamon can be very dangerous. Most videos of cinnamon fails have shown that users start gasping for air when they try to swallow it, sending the spice into their lungs, which can lead to pneumonia or scarring of the lungs.