The most common cosmetic procedure in the United States currently is treatment with botulinum toxin A. It has been proven as a safe and effective treatment for improvement of glabellar lines. It is also commonly used to treat rhytids in the forehead, periocular, perinasal, periorbital, chin, and platysmal areas, among others. Given its extensive safety history and the use of the material in millions of patients for over twenty years, along with its high satisfaction profile and ease of use, knowledge of this treatment is of paramount importance for practicing aesthetic physicians.

Clostridium botulinum toxin type A (BTX-A), developed and marketed as BOTOX Cosmetic by Allergan Inc., is the first type A botulinum toxin approved in the United States and is supplied as a vacuum-dried powder, 100 units per vial. Of note, different botulinum toxins are defined and treated as different products by the Food and Drug Administration (FDA) and other international regulatory agencies. The FDA does not recognize generic biologics (such as botulinum toxins) because the different manufacturing processes alter the final products significantly. Units of BOTOX Cosmetic are not interchangeable with units of other types of botulinum toxin, and there is no recognized conversion factor between different types of botulinum toxin. This is clear since the dose response curves of different toxins are not parallel to each other and the optimal ratio between products appears to be different for different indications. Unreconstituted BOTOX Cosmetic should be stored at 2–8 degrees Celsius.