Botulinum toxin type A for migraine (Botox)

Botulinum toxin type A is a specialist treatment for migraine.

To be eligible for this treatment you must have headaches for 15 or more days each month, with migraine headaches being on at least eight of these days.

It will be given by multiple injections into the muscles around your head and neck.

If you experience any difficulty swallowing, speaking, or breathing after the treatment, speak with your doctor immediately.

Type of medicineA bacterial neurotoxin
Used forTo prevent headaches associated with chronic migraine in adults
Also calledOnabotulinumtoxin A (in US); Botox®
Available asInjection

Botulinum toxin type A is a protein substance which is produced by the bacteria Clostridium botulinum. It is a neurotoxin which means that it interferes with the way nerves work. To be eligible for this treatment you must have headaches for 15 or more days each month, with migraine headaches being on at least eight of these days. You must also have tried several other medicines to prevent migraine before this treatment is prescribed for you.

Botulinum toxin type A is thought to work in chronic migraine by relaxing muscles and by blocking the pain signals which are involved in the development of a migraine. These actions may have the effect of stopping a migraine headache from being triggered.

Botulinum toxin injections are also used for other reasons (including cosmetic purposes, muscle spasms, bladder problems, and excessive sweating). This leaflet does not cover the use of botulinum toxin type A in these ways.

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before being treated with botulinum toxin type A for migraine, make sure that your doctor knows:

  • If you are pregnant, trying for a baby or breast-feeding.
  • If you have an infection or any swelling near any of the areas that will be injected.
  • If you have any muscle problems, particularly any muscle weakness.
  • If you have ever had any difficulty in swallowing or with your breathing.
  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • If you have ever had an allergic reaction to a medicine.
  • Before you start the treatment, ask to read the manufacturer's printed information leaflet from inside the pack. It will give you more information about Botox® and will provide you with a full list of the side-effects which you may experience from having it.
  • You will be given botulinum toxin type A by a doctor who is trained in the use of this treatment. It will be injected into the muscles around your head and neck in several different places.
  • If the treatment proves successful for you, your doctor is likely to recommend that it is repeated every 12 weeks.
  • If you are having an operation or dental treatment, tell the person carrying out the treatment that you have received botulinum toxin type A.

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with botulinum toxin type A. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects may occur following a treatment session even if you have been free from side-effects on previous treatments. You should speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common Botox® side-effects (these affect less than 1 in 10 people)What can I do if I experience this?
Pain at the sites where you have been injected, neck and muscle pain or stiffness, skin rash and itchingThese should soon pass, but if any becomes troublesome, speak with your doctor
Worsening of headache or migraineSpeak with your doctor about this
Eyelid drooping, paralysis of the faceSpeak with your doctor about this

Important: if you experience any difficulty swallowing, speaking, or breathing, speak with your doctor immediately or go to your local accident and emergency department straightaway.

If you experience any other symptoms which you think may be due to the treatment, speak with your doctor or pharmacist for further advice.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

If you buy any medicines, check with a pharmacist that they are safe to use alongside this treatment.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

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Helen Allen
Peer Reviewer:
Dr Helen Huins
Document ID:
13793 (v2)
Last Checked:
22 August 2014
Next Review:
21 August 2017

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.