After how many Kybella treatments do patients usually start to notice a difference?

One.  The results most typically are notable starting 1-2 months after treatment, and continue to improve for 3-5 months after treatment.  It first appears to improve on both sides of the neck, below the jowls.  The fat under the chin is the slowest to keep improving.I have been injecting deoxycholate (aka Kybella) into chin and neck fat for TEN years.  It is a fabulous procedure! There is a bit of art to knowing how to sculpt out the fat, using the proper injection spacing, depth, and volume of deoxycholate....so make sure your injector is well-experienced!The total number of treatments needed depends on the amount of fat you have in the treatment area. Some people only need one treatment session; others may need four!

It is really going to depend on how much fat you have. In general, most patients need between 2 and 4 treatments. See an experienced injector to be assessed in person and get a more accurate idea. 

Kybella uses deoxycholic acid to dissolve the fat in the submental area under the chin. It is a simple procedure that usually takes only about 2-5 minutes to perform. Depending on how much fat you would like to eliminate, and how many vials are injected the first treatment,  one treatment may be sufficient. However, most patients need from two to four treatments to achieve the results they desire. It takes about six to eight weeks to see complete results. Treatments can be spaced apart by one month or more. The results are permanent. Please see a board-certified dermatologist to find out how to get rid of your double chin for good.