Will it be effective again?

I had been getting Botox injections for my square jaw and between my eyebrows regularly a few times. At first, I was satisfied because my jawline became slimmer and my impression softened. However, as the sessions continued, I felt like the effect of reducing muscle size or smoothing wrinkles didn't last as long as before, and I quickly returned to my original state. I suddenly got scared, wondering if I had developed Botox resistance, which I had only heard about, so I stopped the treatments for a while.

It has been a while, and I would like to try managing my condition properly again. I am wondering if I can see results again by switching products or adjusting the dosage, even if I was dissatisfied with my previous treatment like I was. I have heard that there are many pure Botox products these days that have had complex proteins removed to reduce the risk of resistance; I would like to know if it would be safe to improve my condition if I were to receive treatment with such a product. I suppose an imported product would be better, right?