If IPL Causes Collagen to Shrink, is New Collagen Built Around It Always Uniform or Can New Collagen Be Uneven?

In studies that look at the microscopic changes in the skin after IPL treatment for photorejuvenation find that there is an overall increase in collagen in the skin, the collagen fibers are more neatly arranged (as opposed to disordered and fractured in photodamaged skin) and the activity of cells that make collagen (fibroblasts) is increased. 

The majority of patients that undergo IPL treatments see an improved and smoother texture of the skin.

There is no fat loss with IPL.  The machine is not designed for fat reduction and does not do that.  As far as drier skin is concerned, IPL does not affect skin dryness.  Skin dryness is affected by genetics (your skin's inherent state of dry or oily) and most importantly by sun damage which destroys oil glands and dries out the skin.

IPL does tighten existing disordered collagen somewhat but its biggest role is in generating new, fresh collagen and increasing the soft tissue of your skin.  The majority of patients are satisfied with the results of their IPL treatments.