The active substance in NeuroBloc, botulinum toxin type B, is a well-known toxic substance produced by the bacterium Clostridium botulinum. The toxin is the cause of a type of food poisoning called botulism, where patients suffer from muscle weakness and paralysis. The toxin reduces the release of acetylcholine from the nerve endings. Acetylcholine is needed to transfer electrical impulses from the nerves to the muscles in order for the muscles to contract.

In NeuroBloc, the toxin is used as a muscle relaxant. When injected directly into a muscle it reduces the release of acetylcholine and muscle contraction in the affected neck or shoulder muscles, thereby relieving the patient’s symptoms. The effect of an injection of NeuroBloc gradually wears off over time.