Neither of them do, actually.
Caffeine cannot have any negative effects on your growth, nor positive effects.
Caffeine only works inside the brain by fooling the receptors that make you feel sleepy and drowsy.
(Adenosine receptors).
Adenosine is the chemical that makes you tired, does a couple other things, but mainly, makes you tired.
Caffeine is like adenosine, but with none of the effects, it's like an adenosine placebo.
The adenosine Receptors collect adenosine and make you sleepy, but it only has so many spaces for adenosine.
If caffeine, which pretends to be adenosine, but won't make you tired, takes up all the spaces, it won't make you tired, because there's no adenosine to do so.