Commenting on the study, she said, "The problem with any study trying to compare them is that there are variations in the reconstitution measures and final numbers of units used for each drug, and that can have a large impact on the final effect of the treatment. Because these are biologics, and because there are slight differences in the manufacturing process, there will be some differences in how the final product works."
Day pointed out that both drugs are FDA-approved and have good safety track records to date.
Requests by HealthDay for a comment from Allergan were unsuccessful.
For more on botulinum toxin, visit the U.S. Department of Health and Human Services.
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