Skip to main content Skip to navigation

A to Z of MS

Click on the relevant link for more information on a topic.

A to Z of MS Botulinum toxin (Botox, Dysport, Xeomin)

Product names

Botox, Dysport, Xeomin

Botulinum toxin is a drug that is used to treat spasticity, spasms and bladder symptoms in multiple sclerosis.

Botulinum toxin is an extremely potent poison, which was originally developed as a nerve gas before the Second World War. Its therapeutic use is now recognised in a range of symptoms, and it was first used to treat spasticity in MS in 1990. There are several different types of the toxin, with botulinum toxin A the one most frequently used in MS.

How botulinum toxin works

Botulinum toxin works by preventing nerve messages being transmitted to muscles, thus causing paralysis. In small, therapeutic doses, botulinum toxin is injected into individual muscles to prevent the nerve messages that cause spasticity and spasm. It is used to treat bladder symptoms where spasms in the muscle of the bladder wall cause urgency and incontinence.

The effects of an injection with botulinum toxin can last from six to ten months.

How is botulinum toxin given?

Botulinum toxin is injected. As the drug is so potent and misplaced application could lead to the loss of function, injections have to be delivered by a professional trained in the technique. As a treatment for MS, botulinum toxin is only available at specialist centres in the UK.

Side effects and contraindications

The medicinal use of botulinum toxin is generally well tolerated and causes few side effects.


Snow BJ, et al.
Treatment of spasticity with botulinum toxin: a double-blind study.
Annals of Neurology 1990;28(4):512-515.

Kalsi V, et al.
Botulinum injections for the treatment of bladder symptoms of multiple sclerosis.
Annals Of Neurology 2007;62(5):452-457.

Cruz F, et al.
Efficacy and safety of onabotulinumtoxinA in patients with urinary incontinence due to neurogenic detrusor overactivity: a randomised, double-blind, placebo-controlled trial.
European Urology 2011;60(4):742-750.

Patient Information Leaflets

Botox (EMC website)
Dysport (EMC website)
Xeomin (EMC website)

Return to index