Medically reviewed by Bronwyn Jenkins, MD. Last updated 12 September, 2020.
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Many of us think of Botox injections as a way to help conceal the visible signs of ageing. But Botox has its roots in treating a range of medical conditions and is now used as a preventative for chronic migraine.
Botox works to gradually decrease the frequency and severity of migraine headaches, and for many people it’s an effective treatment that improves their quality of life.
Botox (onabotulinumtoxinA) is a purified and highly dilute neurotoxin produced by the Clostridium botulinum bacterium. It’s part of a group of toxins that can cause botulism but in its purified form it’s used both medically and cosmetically.(1)
Botox is used cosmetically to reduce fine lines and wrinkles by blocking the nerve signal to muscles, causing the muscle to relax. How Botox helps chronic migraine isn’t completely understood but it’s generally agreed it affects the sensory nerves involved in migraine pain pathways.
Botox injected in specific sites under the skin around your face and neck help to decrease the release of neurotransmitters (brain chemicals) involved in migraine pain, such as calcitonin gene-related peptide.
Over time, Botox can help to decrease your brain’s sensitivity and dull down its hyper-reaction to migraine triggers. (2,3)
Botox was first used in the 1970s by ophthalmologists to treat eye conditions such as blepharospasm (an involuntary blinking or eyelid spasm), and squint. Since then, it’s been approved to treat other medical conditions including bladder dysfunction, muscle contractions and excessive armpit sweating.
In 1998, an American plastic surgeon reported some of his patients receiving cosmetic Botox experienced an improvement in their migraine headaches after treatment.(3,4)
Encouraged by other anecdotal evidence, researchers began to formally study the efficacy, safety and tolerability of Botox for chronic migraine through clinical trials. The most notable trials were the Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy clinical program, or PREEMPT study.
The PREEMPT study involved 2 double-blind, randomised, placebo-controlled clinical trials (the gold standard of clinical trials) involving 1,384 people who fulfilled the trial criteria of chronic migraine. Half the participants received Botox injections and the other half received a placebo.
The results from the clinical trials were combined and the study concluded treating chronic migraine with Botox reduced the number of migraine days and reduced headache-related disability.(5)
From PREEMPT, the Food and Drug Administration (FDA) approved Botox for use in chronic migraine in 2010. In Australia, Botox was approved for use in chronic migraine in 2011.
Botox injection sites for chronic migraine differ from the sites used cosmetically. A specific Botox protocol for chronic migraine was developed and tested extensively over 10 years to discover the most effective injection sites and dose.3 One Botox treatment involves 31 injections around your forehead, sides and back of your head, and your neck, using 155 units of Botox.
Botox is the brand name of onabotulinumtoxinA approved for chronic migraine and is made by the pharmaceutical company Allergan.
Further prospective and retrospective studies support the results of the PREEMPT study. The COMPEL study, which began in 2011, included 716 patients with an average of 22 headache days per month. The participants received 155 units of Botox at the 31 injection sites from the established migraine protocol every 12 weeks for 2 years. Just over half the participants completed the study and by weeks 60 and 108, there was a significant reduction in headache days reported.(6)
In 2019, researchers reviewed the data from 211 patients who received Botox at 7 private neurology practices in Australia. The study found 74% of patients benefitted from Botox treatments, including reduced headache days and a decrease in the number of days they used acute pain medication.(7)
Botox is approved only for chronic migraine and there’s no evidence to support its use to help treat episodic migraine or tension type headaches.3
In Australia, Botox for chronic migraine is accessible on the pharmaceutical benefits scheme (PBS) from a neurologist trained in Botox use. To qualify, you must meet all of the following criteria:
To continue to receive Botox on the PBS you must achieve and maintained a 50% or greater reduction from baseline in the number of headache days per month after 2 treatments, 12 weeks apart.(10)
Botox treatment is expensive if you do not qualify for PBS coverage. When covered by the PBS, the government pays the majority of the cost. The amount you pay per treatment can vary significantly and may be a few hundred dollars when including consultation fees. Botox requires seeing a neurologist every three months while treatment is administered.
Before your first Botox treatment your neurologist should discuss the side effects and risks. This is a good time to ask questions and check if they follow the established Botox protocol for chronic migraine.
Your neurologist uses a small needle to inject 0.1ml or 5 units of Botox at each site just under your skin. You may feel a slight sting with each injection. Because Botox comes in 100 unit vials some neurologists may do a few more injections around areas where you experience your migraine pain.
The treatment takes about 15–20 minutes and there aren’t any restrictions on driving or other daily activities after treatment.
It’s important to remember Botox isn’t a quick fix for migraine. It often takes 2 or 3 treatments to notice if it’s effective in reducing the frequency or intensity of your migraine pain. Botox treatment is repeated every 12 weeks, which means it may take 6–9 months to notice any difference. Some people have reported improvements after their first treatment, so like many migraine treatments results are very individualised.
Many people report the benefits of Botox start to wear off after about 10 weeks, and the intensity and frequency of their migraine attacks increase close to their next treatment date.
You don’t need to stop taking other preventative medications with Botox treatments and you can continue to use abortive medications if you need them.
If after 3 treatments your migraine headaches haven’t improved, Botox may not be the right treatment for you.
Like other medications, there are a few side effects and risks with Botox, though most are rare and only temporary.
The most common side effect following Botox treatment is neck pain, reported in about 9% of people during the PREEMPT study.
About 5% of people from the PREEMPT clinical trials reported a migraine following treatment, however headache and migraine usually occur within the first month of treatment and decrease with repeat treatments.8
Other side effects include:
Rare but serious side effects include breathing and swallowing problems and the spread of the Botox toxin.(9)
Botox for chronic migraine is only approved for people aged 18 and older and its safety during pregnancy and breastfeeding is unknown.(2)
Botox has been used to treat medical conditions for many decades and it’s an evidence-based treatment option for people with chronic migraine. Side effects are rare and mild and many people’s biggest fear are the needles.
As well as the quantitative effects Botox can have, such as a decrease in the severity and frequency of migraine attacks, there’s also the little day to day things we often forget we’re missing out on.
Botox may help you to claim back hours previously lost to migraine, including:
Botox isn’t a quick-fix solution for chronic migraine and if it works, you need to continue treatment every 12 weeks for ongoing benefits. Botox isn’t a cure, and like other migraine treatments such as preventatives, abortives and lifestyle changes, Botox is another piece of your treatment plan.
If you qualify for Botox on the PBS and you’re prepared to spend more of your migraine ‘budget’, Botox can be a great treatment option for chronic migraine that can help to give you back more migraine free days.
Sarah Cahill – Medical Writer.