Lip fillers not working? (Photo)

I am starting to think that I am not normal lol. I have got 3 full syringe of fillers in my lips over the course of 6 months. We go 1 syringe at the time. My lips are healing very well and quick. After 3-4 weeks, my lips have close to no visible results and augmentation. I have been taking pictures and between 0 fillers and 3 syringes, there’s almost no difference. I don’t understand. I feel like I am wasting my money. What is the cause? The product? My metabolism? Am I broken?