Answer: caffeine

AnswerCrossword Clue
CAFFEINE

Chocolate ingredient

CAFFEINE

Joe's stimulant

CAFFEINE

Eye-opener, literally

CAFFEINE
It can keep you up
CAFFEINE
Red Bull ingredient
CAFFEINEThe quicker picker upper?
CAFFEINECoffee's kicker
CAFFEINEMild stimulant
CAFFEINECoffee's kick
CAFFEINECola ingredient
CAFFEINECommon alkaloid