Dysport® (Medicis, Scottsdale, AZ) is the formulation (previously known as 52120 and Reloxin®) of Clostridium botulinum type A (BoNT-A) toxin-hemagglutinin complex to be used in the United States (US) cosmetic clinical program. It is identical to the Ipsen product marketed outside the United States and under clinical studies in the United States for cosmetic and non-cosmetic use. Dysport® injections are used to relax the musculature of the upper face, reducing the appearance of dynamic rhytids. Previously FDA-approved Botulinum type A toxins have been utilized in the upper face to treat glabellar rhytids for nearly two decades. Botox® Cosmetic (Allergan, Irvine, CA), is the first FDA-approved Botulinum toxin type A to be approved in the United States for the treatment of glabellar rhytids. Its efficacy and safety have been proven in multiple studies. However, no comparison to onset of action exists amongst the different BoNT-A products. This study seeks to compare the onset of action between two BoNT-A products, Dysport® and Botox® Cosmetic.