No, it does not, it all depends on the tune and what shot you are running. a lower shot is just fine. people get into trouble when they try putting a 200 shot on a motor that can only handle a 100. if you run a 35-50 shot on stock internals and tune right, you will be just fine!
The question is ambiguous and thus has no proper answer.
If done improperly any modification can hurt an engine.
Basically you can add Nitrous Oxide so long as you have the proper fuel and spark retard and you do not exceed the limits of any of the associated parts, e.g. too high of combustion pressure.