This is such an important question and I'm glad you're doing your research before just picking someone random! The credentials definitely matter, but honestly, experience and artistry matter even more. A plastic surgeon who rarely does lip filler might not be as skilled as a nurse injector who does hundreds of lip treatments every month. What you really want to look for is someone who specializes in facial aesthetics and does a high volume of the specific treatment you want. Check their before/after photos extensively - and I mean really look at them to see if their aesthetic matches what you're going for. Do their results look natural or overfilled? Can you see a variety of different lip shapes and sizes, or does everyone look the same? That'll tell you a lot about whether they customize treatments or just have one approach for everyone. Read reviews carefully, especially looking for comments about bedside manner, how they handle complications, and whether they pressure people into buying more than they wanted. Schedule consultations with a few different providers and pay attention to whether they listen to your goals or just try to sell you on what they think you should get. Trust your gut - if someone makes you feel uncomfortable or rushed, that's a red flag!