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Botox for Chronic Migraine

Botox for Chronic Migraine Overview

Botox, or onabotulinum toxin A, is a drug made from the bacteria Colistridium botulinum. It is well known for its ability to reduce and smooth facial wrinkles, but it can also be an effective treatment for the prevention of chronic migraine. Researchers began exploring Botox for migraine after people who received Botox for cosmetic purposes reported an improvement in their migraine symptoms. Trials were initially designed to evaluate its efficacy in treating episodic migraine, but those studies did not show a significant benefit. Botox was subsequently studied in patients with chronic migraine diagnoses and found to be effective.  

Two large studies have been performed evaluating the effectiveness and safety of onabotulinum toxin A. These studies found that Botox significantly reduces the number of headache and migraine days in patients with chronic migraine (defined as having more than 15 headache days per month, with at least eight of them being migraine headaches). These findings led to the approval of Botox injections by the U.S. Food and Drug Administration (FDA) for the treatment of chronic migraine.

What is Botox for chronic migraine used for?

Botox has been approved by the U.S. Food and Drug Administration (FDA) as a preventative treatment for chronic migraine, which is characterized by headaches that occur at least 15 days per month and last four hours or more. Insurance companies usually require people to try at least two other “first-line” preventative medications before they will authorize and approve Botox for chronic migraine.

How does Botox work to treat migraine?

The mechanism by which Botox works to treat migraine is complex. It is thought to function by reducing the release of inflammatory and excitatory neurotransmitters and proteins. 

Neurotransmitters are chemicals that the nervous system uses to transmit signals between nerve cells, which are also called neurons. Proteins are large biological molecules that perform important structural, functional, and regulatory functions in your cells. 

One of these protein neurotransmitters is calcitonin gene related peptide, or CGRP, which can be elevated in people who are suffering from migraine. 

Sensory nerve endings are considered to be overactive in patients with migraine. Botox helps to prevent pain signals from being sent to the brain from the peripheral nerves and is also thought to reduce the activity of CGRP.

CGRP is a target of several other migraine-specific preventive and acute medications.

photo showing a patient receiving botox injections for the treatment of chronic migraines at the jan and tom lewis migraine treatment program at barrow neurological institute in phoenix. Dr. kerry knievel is shown administering the shots.
A patient receives botox injections for the treatment of chronic migraines at Barrow

How is Botox administered?

Botox for chronic migraine consists of 31 injections in the head and neck every 12 weeks. Injection sites include the forehead, temples, back of the head, upper neck, and shoulders. Each treatment takes less than 10 minutes, and the injections are generally well tolerated.

What are the potential side effects of Botox?

One of the most common side effects of Botox is weakness. Because Botox for chronic migraine is injected around the face, head, neck, and shoulders, patients could experience the following side effects:

  • Drooping of the eyelid or eyebrow
  • Neck weakness
  • Shoulder weakness

Avoiding any rubbing of the injection sites for 24 hours can help reduce, but not eliminate, the risk of weakness. If weakness does occur, it tends to be transient and usually resolves within 12 weeks. Other potential side effects include:

  • Headache
  • Neck pain
  • Flu-like symptoms
  • Muscle pain

Am I a good candidate for Botox for chronic migraine?

You may be a good candidate for Botox injections if you are an adult suffering from chronic migraine. Botox is not FDA approved for people with migraine who have 14 or fewer headache days per month.

Because Botox can cause serious side effects, it is important to tell your doctor about any other medical conditions you have and any medications you take. You may be at higher risk for serious side effects, such as difficulty swallowing or breathing, if you have neuromuscular conditions such as amyotrophic lateral sclerosis (ALS), myasthenia gravis, or Lambert-Eaton syndrome.

You should not receive Botox injections if you have had an allergic reaction to any botulinum, including:

  • Myobloc®(rimabotulinumtoxinB)
  • Dysport®(abobotulinumtoxinA)
  • Xeomin®(incobotulinumtoxinA)

Information and Resources About Botox for Chronic Migraine

National Library of Medicine
Botox for Chronic Migraine

Medically Reviewed by Kerry Knievel, DO, FAHS and Shane Root, MD on September 3, 2022