Mesotherapy is unregulated and there are no standard procedures. The Aesthetic Surgery and Education Foundation is currently conducting an FDA approved study into mesotherapy to see whether it actually works and what, if it does, the syringe should actually contain.
Mesotherapy uses a cocktail of fat cell busting medications, vitamins and plant extracts. No two doctors will necessarily administer the same cocktail. Some seem to use an emphysema drug called aminophylline. One study in 1999 suggested that there is no evidence that aminophylline works. Other practitioners use a couple of biological detergents (one comes from cow bile) that are known fat cell busters. One of them, phosphatidylcholine is a licensed drug in Germany for treating blood vessel blockages. It is not licensed for cosmetic surgery.