The Reactions YouTube channel has released a fascinating video explaining the science behind the world’s most popular drug, caffeine.

How does caffeine work? Caffeine enzymes block the molecule adenosine from doing its job. Adenosine is responsible for slowing down nerve activity in our brains, which gives us the signal to calm down and take a nap.


Once caffeine starts doing its job, it works to:

  • Heighten brain activity
  • Increase athletic performance
  • Increase flow of oxygen and nutrients to the brain
  • Reinforce your ability to concentrate and increase heart rate


While too much caffeine (about 75 cups of coffee) can be toxic, scientists have found that that up to 400mg of caffeine per day is safe for adults.

That translates to to:

  • Three 8oz cups of brewed coffee
  • Five 8oz Red Bulls
  • Eight 8oz cups of black tea




[via YouTube]