Botox resistance?

A few months ago, as part of a first-time treatment event at the dermatology clinic

I went because I heard I could get Botox cheaply, but

It is said that domestic Botox can lead to resistance.

They recommended the more expensive one.

But I just got the domestic one.

Isn't resistance okay if I get it about once every six months?

Should I alternate between domestic and imported Botox?