Botox Cosmetic, Dysport, and Jeuveau are “neuromodulators.” They relax muscles by modulating the effect of our neurotransmitters on the muscles into which they are injected. This means that when we try to use a muscle that has been treated with one of these products, it will not respond or it will respond weakly. This effect is temporary and wears off over time, usually 3-4 months, depending upon which area has been treated.