They're definitely not all the same. There are various types of fillers out there with different formulations, consistencies, and longevity. The main category used for lips is hyaluronic acid-based fillers because it's natural to the body and provides good results. Within that category though, different brands have different formulations and some are specifically designed for lip work while others are more general purpose. The quality and texture really matters when you're talking about lips because you want something that moves naturally with your mouth and doesn't feel stiff or artificial. It's worth asking your specialist which specific products they recommend and why.