The active ingredient of Bocouture (which is made by Merz Pharma UK) is Botulinum toxin A, and is a prescription-only medicine. It works by blocking the nerve impulses in all injected muscles. This prevents muscles from contracting leading to temporary and reversible relaxation. BOCOUTURE is used for temporary improvement of upper facial lines in adults under 65 years of age when the severity of these lines has an important psychological impact for the patient: Moderate to severe vertical lines between the eyebrows seen at maximum frown and/or Moderate to severe lateral periorbital lines seen at maximum smile and/or Moderate to severe horizontal forehead lines seen at maximum contraction