Botulinum Toxin in Aesthetic Medicine: Myths and Realities.

[BACKGROUND] Several formulations of Botulinum toxin serotype A (BoNT-A) for aesthetic indications are available, with numbers likely to increase. Preparations are not interchangeable, based on dose unit comparisons.

[OBJECTIVE] Numerous myths and misconceptions regarding the use of BoNT-A for aesthetic indications have arisen, which this review aims to lay to rest.

[MATERIALS AND METHODS] This review assesses evidence for and against each of the most common myths regarding BoNT use in aesthetics.

[RESULTS] BoNT-A neurotoxin/protein complexes are irrelevant to the toxin's therapeutic/aesthetic indications. BoNT-A neurotoxin/protein complexes do not influence movement from injection site or immunogenicity. Any relationship between neutralizing antibody formation and clinical response is complex and clinicians should consider other factors that may induce an apparent loss of clinical response. Diffusion appears predominately, perhaps exclusively, dose dependent. Careful placement and correct dosing optimizes likelihood of good outcomes. Manufacturers recommend reconstitution of products with sterile nonpreserved saline. However, compelling evidence suggests that reconstitution using preserved saline dramatically improves patient comfort without compromising efficacy. Several post-treatment instructions/restrictions are widely used despite the lack of evidence, but muscle activity after injection may be beneficial. Cooling the treatment area might hinder BoNT-A translocation and should probably be abandoned.

[CONCLUSION] The existing evidence suggests that experienced users should achieve equivalent results regardless of BoNT-A formulation, but additional, well-designed, adequately powered, controlled randomized studies should be performed.