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What are the side effects of Botox for migraine?

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AboutCommon side effectsLonger-lasting side effectsSerious side effectsAnaphylaxisWhat to expectDosage and frequencyBotox for childrenSummary
Botox is a popular way to enhance your appearance, but it also treats migraine. Side effects can be mild and localized, while others may be more severe.
Medically reviewed by Deena Kuruvilla, MD
Updated on March 29, 2023

Botox is a well-known injectable treatment widely used for cosmetic purposes. For example, it’s popular for reducing the appearance of wrinkles.

In recent years, Botox has also been useful in treating migraine — a common and often debilitating condition.

Migraine and Botox

adult female with head bowed and forehead resting on their fingers as if to ease a headache and they could be considering botox for migraine
Jamie Grill/Getty Images

Healthcare professionals characterize migraine as recurring and severe headaches, often accompanied by other symptoms like nausea, light and noise sensitivity, and visual disturbances known as aura.

According to a 2022 systematic review, Botox injections can reduce the frequency and severity of migraine symptoms in some people. Plus, a 2020 review suggests Botox may also help treat other headache types, including cluster and whiplash-related headaches. However, it currently only has approval from the Food and Drug Administration (FDA) for chronic migraine.

Although the causes and triggers for migraine are not well understood, researchers suggest that Botox improves migraine by blocking the release of certain chemicals in the brain that are responsible for pain and inflammation.

Common side effects of Botox for migraine

The FDA approves Botox for treating chronic migraine, which doctors and healthcare professionals define as having a headache for 15 or more days each month, with 8 days meeting the formal migraine episode diagnosis.

Despite this approval, and even though Botox is generally considered a safe and effective migraine treatment, it’s important to be aware of the potential side effects and know how to manage them.

Injection site side effects

The most common side effects of Botox for migraine are injection site reactions that can include:

  • pain and soreness
  • skin reddening (erythema)
  • dropsy
  • drooping of the upper eyelid or brow (ptosis)
  • bruising

These side effects are generally mild and resolve on their own within a few days.

You can apply an ice pack to the injection sites to reduce inflammation, swelling, and discomfort. You can also use over-the-counter (OTC) pain relievers like acetaminophen or ibuprofen.

If these symptoms don’t improve within a few days to a week, or if they start worsening, it’s best to consult a doctor for advice.

Mild cross-body symptoms

Some people experience flu-like symptoms across their body after the procedure, including:

  • fatigue
  • headaches
  • nausea

These side effects are also generally mild and typically resolve within a few days. To manage them, be sure to stay hydrated and get plenty of rest. If the symptoms worsen, it’s best to talk with a doctor to find out if you need further treatment.

Longer-lasting side effects

Botox injections also come with a risk of longer-lasting side effects. In some people, these are significant enough to discontinue the treatments.

An older 2005 study looked at 45 participants over 12 years of receiving regular Botox injections, and 20 of the study’s participants reported adverse side effects that included:

  • neck weakness
  • muscle soreness
  • difficulty swallowing
  • drooping eyelid
  • nausea
  • vomiting
  • blurred vision
  • general weakness
  • chewing difficulties
  • hoarseness
  • difficulty speaking
  • heart palpitations

However, further research is necessary to confirm the long-term effects of Botox for migraine.

If you experience any of the above symptoms, contact your doctor or healthcare professional for tailored advice and treatment options.

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Serious side effects

Botox contains Botulinum neurotoxin-A, a toxin created by the Clostridium botulinum bacteria. This toxin can cause a type of poisoning known as botulism.

There are some reports of Botox treatments causing the toxin to spread from the injection site to other parts of the body, causing symptoms similar to those of botulism.

Symptoms of botulism include:

  • general weakness throughout your body
  • muscle spasms
  • double vision
  • drooping eyelids
  • difficulty swallowing
  • a hoarse-sounding voice and inflammation of the pharynx in your throat
  • urinary incontinence
  • breathing difficulties

These symptoms can appear hours to weeks after the procedure. If you experience any of these, it’s important to seek urgent healthcare.


On rare occasions, serious allergic reactions to Botox treatments occur, including a potentially life threatening condition known as anaphylaxis. If you experience this type of allergic reaction, symptoms may include swelling in the throat or face and breathing difficulties.

As these symptoms are often immediate, a doctor or healthcare professional will typically be on-hand to manage the reaction quickly. This often means administering epinephrine and methylprednisolone via injection, followed by close monitoring and a possible hospital stay.

What to expect from the procedure

During the procedure, a doctor or healthcare professional will inject Botox at around 30 different places in your head and neck. Each session can take up to 30 minutes.

You may experience mild discomfort during the procedure, though the injection process is typically well-tolerated.

Dosage and frequency

Using Botox to manage migraine symptoms, also known as a “migraine attack,” is not a single procedure, and generally, you will receive injections every 12 weeks.

The FDA recommends administering 155 units over 31 injection sites. Five units contain 0.1 milliliters (ml) of Botox, making the total dosage 3.1 ml.

That said, the dosage and injection frequency can vary depending on your individual needs and how you respond to the treatment.

Can children get Botox for migraine?

The FDA does not typically recommend Botox injections for migraine in children under the age of 18 years.

A 2022 study of 25 people ages 13–21 years suggests that Botox can reduce migraine frequency and severity in people under 18. However, more research is necessary to confirm the effects.

A doctor may still recommend this approach in certain cases of chronic and severe migraine. If so, they will carefully tailor the dosage and frequency of injections to the specific child.


While Botox is generally well-tolerated and effective, it’s not a permanent cure for migraine.

Some people don’t experience any side effects from Botox, while others may experience mild symptoms like swelling and soreness at the injection sites.

Although rare, the injections also come with a risk of more severe side effects like nausea, muscle weakness, and even potentially life threatening conditions like botulism and anaphylaxis.

If you are considering Botox for migraine, it is important to discuss the potential benefits and risks with your doctor and carefully follow their instructions for treating and managing side effects.

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