Is it normal for your injector to mix Kybella with saline? If so, does that make it less effective?

I don't know of any advantage to mixing Kybella.  This will lessen the strength of Kybella and will make it less efficacious.  Best of luck!
 

Kybella is made to be injected as is which means that it should not be diluted. It will lessen the efficacy. I would suggest that you see another injector, preferably a board certified plastic surgeon or cosmetic dermatologist.