When done by a professional experienced with injectables, results can often be seen almost immediately after treatment.  When done correctly there is very little bruising or swelling immediately.

Over the course of the next 3-5 days you may then see some minor swelling, but after the 5th day that should be resolved almost entirely.  As always, consult a Board Certified Plastic Surgeon before making any decisions regarding treatments, to discuss the best options unique to your situation.