XEOMIN is an effective drug that is used to treat pain in the head and neck pain symptoms that occur during Cervical Dystonia. It is also used to treat muscle spasms in the eyelid which is otherwise known as Blepharospasm. The Blepharospasm is usually an effect of Botox. How does Xeomin work on muscles? Once XEOMIN has been injected into the muscles, it starts to inhibit acetylcholine from being released. It is this chemical which makes fibers in the muscle to contract, so without acetylcholine, muscles will contract less, resulting in less spasms and discomfort to the individual.