Derived from coffee; rejuvenates, restores firmness,
and protects skin. Caffeine reduces the appearance
of puffy eyes while firming and tightening the skin.
It is one of a group of alkaloids called methylxanthines.
It is a substance with a high tannin content,
which constricts skin and can cause
irritation. The theory is that when
caffeine is applied to skin it would
have the effect of "flushing away"
