BACKGROUND. Botulinum A toxin has been well documented as a successful
treatment for hyperfunctional upper facial expression lines. Currentl
y, there are two commercial sources for botulinum toxin-Botox(R) and D
ysport(R). Only Boton: is currently available in the United States; ho
wever, both Botox(R) and Dysport(R) are available in a number of Europ
ean and other countries. OBJECTIVES. There are several differences bet
ween 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 bot
ulinum toxin for facial expression lines. RESULTS. One unit of Botox(R
) is approximately equivalent in potency to 4 LT of Dysport(R). CONCLU
SIONS. Both commercial types of botulinum toxin can be used interchang
eably with appropriate dosage selection. (C) 1998 by the American Soci
ety for Dermatologic Surgery, Inc.