Some folks who don't get strong enough hunger control from reta end up doing better switching to tirz. Reta failing to fully quiet appetite isn't rare at all.
That's actually why I run both together, keeping each dose modest (1mg tirz plus 2mg reta, same day weekly, sometimes stretched longer depending on how hunger's behaving) and I'm getting steady weight loss with basically no appetite noise (10 pounds this past month, 45 total dating back to when I was only running 1.5 of tirz in January).