Does it exist any difference between theine and caffeine?

Actually, there is no difference between theine and caffeine, as this is the same molecule.

However, we can observe that they have different impacts, as they are drunk with different manners. For instance:

• quantity :there is 3 to 4 times more caffeine in coffee than in a tea cup (presuming this is not an espresso)
• absorption is different: caffeine enters directly in the blood with a cup of coffee, where as in tea, theine is associated with tea tannins. These tannins are slowing down the effect of theine over time.

Relaxing effect brought by tea comes also from theanine, which does not exist in coffee. This molecule is relaxing our brain.