When I first read about mesotherapy, I thought it sounded too good to be true; but a woman patient of mine, lifted her shirt and convinced me.
Back in 1952, a french physician had the idea of injecting medication between the skin and the muscle to get a local effect.  Using medication that causes breakdown of the cell wall of the fat cell, he hoped to cause spot reduction.  Other effects (increased circulation, less hair loss, etc.) were investigated but the main thing he was looking for was a way to spot reduce.
After going to several conferences where where a few physicians were bragging about how well their patients were doing, I decided to investigate for myself.
So, I read the medical literature and travelled to Toronto, Canada to work with a physician who supervises 72 spas accross Canada.  I wanted to learn his technique, but more importantly wanted to meet patients who were being treated successfully.
I people who were doing well with the thrapy and proceeded to learn the technique and have been using it with much success in my office. 
But the best lesson came from a patient soon after I flew back from Toronto.  I mentioned the trip to a woman patient from Columbia (I have several) and she became excited and told me that mesotherapy is used commonly in South America.  She continued to tell me that several years ago she was treated with mesotherapy by a physician in Columbia and now had a "hole" in her stomach.  I was curious about this "hole."  So, she lifted her shirt to reveal what was not a hole but was the groove between the abdominal muscles.  You could actually see the skin lying accross the top of the upper abdominal muscles like what you might see in a young teenage boy with the mid-line groove between the muscles (the six-pack) visible.
Just wanted to let you know about the proceedure and to give you a link that takes you to some real research about mesotherapy and to a position paper from the Alabama Board of Medicine.
The main material used in mesotherapy is FDA approved but the proceedure is still being debated in the medical literature.  I'm convinced that used for the right reasons by a physician who knows what he/she is doing--mesotherapy is a useful tool for spot reduction.
Peace & Health,
P.S. My book on men's health and sexual function is being translated into Japanese.  If you have not read it yet, you may want to read it soon.  I'm getting email from all over the world from people telling me that it has helped coach them to better health and to better sexual function.  It's also written for women to be able to tactfully give to a man (and the exercise/diet sections of the book apply to women).