Is Azzalure more effective than Botox? If so, why?

I have had Botox done a few times. I'm sure that the first few times I had it done, they used Azzalure, but more recently I've had Botox. With Azzalure, my forehead was literally frozen for nearly 6 months, but with Botox, I could still move my forehead, it seemed a lot less effective and wore off much quicker. Is that usually the case? My doctor says she won't use Azzalure because it's not as safe as Botox, and that Azzalure is cheaper for a reason.