The U.S. Food and Drug Administration has approved four distinct formulations of botulinum toxin (BoNT) serotypes A and B (BoNTA and BoNTB) for medical use. These four products are indicated for many medical applications, but the three BoNTA formulations are the most widely used worldwide and are the only products approved for aesthetic use. The latest approval of a BoNTA with no complexing proteins (incobotulinumtoxinA) necessitates a review and discussion of differences between available formulations and the effect that these differences may have on clinical practice.


To review the history, science, safety information, and current and emerging applications of BoNT in clinical and cosmetic practice and to compare commercially available BoNTA formulations.

Methods and Materials

Publications, clinical trials, and author experience were used as a basis for an up-to-date review of BoNT and its use in human medicine. The similarities and differences between formulations are presented, and diffusion, spread, equivalency ratios, stability, and storage are discussed.


Each commercial formulation has unique characteristics that may influence its use in aesthetic medicine. Familiarity with the similarities and differences between products will aid physicians in making patient care decisions.


New formulations, emerging uses, and continued research into the science and uses of BoNTA will lead to increasingly refined therapeutic approaches and applications. Continued education is important for physicians to optimize use of the agent according to the most current evidence and approaches.