Background: Some facial furrows are accentuated with facial expressions due to contraction of the muscles beneath the surface of the face. The wrinkles with movement also known as dynamic furrows can be softened or some cases eliminated with agents that temporarily weaken the underlying muscles of the face.

Treatment: Selective injection into the muscles responsible for the undesirable facial furrows requires a thorough understanding of the underlying anatomy. Once injected, it typically takes a few days, for the relaxation of the furrows to begin, peak softening of the furrows occurs within 2 weeks, and the effect lasts around 3 to 4 months. At that time the injections may be repeated.