Xeomin is a version of botulinum toxin that has already been available to doctors for years. It helps stop muscle spasms, so it's become a common treatment for people who have chronic neck or eyelid twitching. It's similar to Botox in effectiveness, lasting time, and safety. Where it differs however, is in storage and preparation. Xeomin could start a price war simply because it's powdered and doesn't need to be refrigerated. Botox and previously approved alternative Dysport are both liquids that must be refrigerated at all times, so shipping and storing them isn't easy. Xeomin, on the other hand, can sit on shelves for years and is simple to mix into saline for injection. And Xeomin's creator, Merz Pharmaceuticals, just lowered its price by 20 percent, making it even more competitive. It's a lot less effort and expense for providers, and the hope is that they'll pass the savings along to consumers.