The best way to know is to check your plugs. Most Suzuki’s (and most new bikes in general) come from the factory jetted on the lean side to pass emissions tests easier. I think that most slip ons will require a rejet, not as big of change as a whole exhaust system would require but still the slip on is going to be a little free-er flowing than the stock can. Better safe than sorry as they say, I’d check it or get it checked if I were you a lean condition can ruin an engine. On the plus side if you on running lean and you re-jet to the proper jet you will likely see a gain in power.
Here’s a good link on reading plugs to get you started.