Background: Botulinum A toxin has been well documented as a successful treatment for hyperfunctional upper facial expression lines. Currently, there are two commercial sources for botulinum toxin--Botox and Dysport. Only Botox is currently available in the United States; however, both Botox and Dysport are available in a number of European and other countries.
Objectives: There are several differences between these two sources of botulinum toxin, including different potency of their dosage units. This article will review the uses of these two sources of botulinum toxin and discuss the dilution and dosing of botulinum toxin for facial expression lines.
Results: One unit of Botox is approximately equivalent in potency to 4 U of Dysport.
Conclusions: Both commercial types of botulinum toxin can be used interchangeably with appropriate dosage selection.