Caffeine

Caffeine is a stimulating substance that is commonly found in coffee, although various forms of tea and carbonated drinks can contain this substance.

Empath: The Luckiest Smurf stories
In the EMPATH: The Luckiest Smurf story series, caffeine is for the most part absent in the Smurf versions of coffee and tea, so a substance called hypertine which is a sugar substitute is used as a stimulating additive, since it contains caffeine.