Frequently Asked Questions about Onabotulinumtoxin A (Botox) for Migraine

Learn more about Botox for migraine, including how injection therapy works, what treatment feels like and what the potential side effects are

Migraine management often involves preventive and acute treatments. Acute treatments help manage individual attacks, and preventives work to reduce the frequency, severity and duration of attacks. When developing a treatment plan with your physician, OnabotulinumtoxinA may be one of your preventive options. But what is Onabotulinum A and why is it used for migraine?

To learn more about OnabotulinumtoxinA, we posed some frequently asked questions to Dr. Carrie Dougherty, an assistant professor of neurology at the MedStar Georgetown Headache Center, who helped explain how this preventive treatment works and who is a possible candidate for treatment.

What is Onabotulinumtoxin A?

OnabotulinumtoxinA, also known as Botox®, is a form of botulinum toxin, a neurotoxin. A neurotoxin is a poison which acts on the nervous system. When purified and used in small doses, OnabotulinumtoxinA temporarily prevents muscle contractions in the muscle in which it is injected, which can reduce pain for approximately three months. It’s believed that onabotulinumtoxinA blocks pain signals in nerves in the head, neck, and shoulders.

How does Onabotulinum A help migraine?

In October 2010, the Food and Drug Administration (FDA) approved OnabotulinumtoxinA injection therapy for the preventative treatment of chronic migraine, which is defined as 15 or more headache days per month.

“Botox® injections for migraine can help to reduce frequency and severity by blocking the transfer of information from the motor nerve to the muscle,” says Dr. Dougherty. “Once the procedure starts to take effect—usually within a couple of days—the Botox® can decrease pain signaling in migraine.” Botox® can reduce migraine attacks because it blocks certain chemicals that cause the pain of migraine.

In clinical trials, OnabotulinumtoxinA has been shown to reduce the number of headache days per month on average by about 50%. Because migraine attacks come with unpredictable frequency and are dependent on many factors, it may take much longer, or several treatments, to tell if the OnabotulinumtoxinA is really working.

What is Onabotulinumtoxin A treatment like?

A round of OnabotulinumtoxinA treatment involves injecting a small amount of the medication into 31 specific points. These points are above the bridge of the nose, forehead, temples, back of the head, top of the neck and the trapezius muscles that run from neck to shoulder. “These are all points where nerves are active during migraine,” says Dr. Dougherty.

When treatment is performed by an experienced injector, the entire process is fairly short and is usually well tolerated. More information about side effects is listed below. “The procedure itself goes quickly, about 20 minutes,” says Dr. Dougherty. “It usually takes me longer to explain the procedure than to actually perform it.”

Immediately after the treatment, the vast majority of patients are able to return to their routine daily activities.

Patients typically receive injections every 12 weeks or at intervals recommended by their doctor. The studies used for FDA approval of OnabotulinumtoxinA involved a schedule of injections every three months, with a total of five treatments over 15 months. In clinical practice, some patients receiving OnabotulinumtoxinA improve to the point where they can discontinue injection therapy without relapse to chronic migraine.

Can I take other medications for headache while I’m receiving Onabotulinum A treatment?

The short answer is yes. Patients can use acute migraine treatments while receiving OnabotulinumtoxinA treatment. Many clinicians have found preventive migraine medications to increase the beneficial effects of OnabotulinumtoxinA in helping to reduce chronic migraine attacks. There is no convincing evidence that use of medications intended for migraine prevention will block the positive effect OnabotulinumtoxinA.

Who should get Onabotulinum A for migraine?

Patients who have not experienced relief from other preventive medications are good candidates for OnabotulinumtoxinA. “In general, chronic patients who try two or three oral preventives and don’t have consistent results should discuss Botox® as a treatment option with their doctor,” Dr. Dougherty says.

OnabotulinumtoxinA wouldn’t be a good option for people with a history of neuromuscular disorders or pre-existing conditions such as difficulty breathing and myasthenia gravis, says Dr. Dougherty. It is also not appropriate for patients who are pregnant or trying to become pregnant.

Does insurance cover Onabotulinum A for migraine?

OnabotulinumtoxinA is FDA approved for the treatment of chronic migraine, and most insurance carriers, including Medicare and Medicaid, now cover the treatment. This means you will be responsible for any co-pay, which will amount to a small fraction of the total cost.

However, most insurance companies require that patients try at least two or three other preventive medications before covering OnabotulinumtoxinA. Once a patient has tried other preventives but not experienced a positive response or had intolerable side effects, they can move on to trying OnabotulinumtoxinA.

It’s important to note that virtually all insurers require prior authorization. Receiving OnabotulinumtoxinA injection therapy without prior authorization could result in your being held responsible for the entire charge. The American Migraine Foundation recommends working with your provider to make sure any notes or letters about your medical history are filed and approved before beginning treatment. It’s important to be patient with your provider as the prior authorization process can sometimes take weeks to complete.

What are the side effects of OnabotulinumtoxinA for migraine?

The most common side effect of this treatment is neck pain and stiffness, typically in the week following the procedure. Dr. Dougherty says this neck pain is due to other muscles compensating for those inhibited by the injection. Other side effects may include a headache the day of or day after the procedure.

With the first set of injections, any improvement in your headache disorder may take as long as 10 to 14 days. “Patients often see improvement by the second or third round of Botox® injections,” says Dr. Dougherty. “The initial results may be a reduction in severity, noticing that an abortive medication works better or missing fewer days of work.” Patients who note no improvement in their headache disorder after two (or perhaps three) treatments are unlikely to become responders if treatment is continued.

OnabotulinumtoxinA injected into the forehead may also temporarily change cosmetic appearance, such as wrinkle reduction and change in the arch of the eyebrow, and less commonly lead to a temporary drooping of the eyelid. Rarely, patients can experience flu-like symptoms such as muscle aches, fever and a general feeling of illness. This typically lasts only a few days at most and is unlikely to recur with future injection treatments.

Learn more about Onabotulinum A as a treatment for chronic migraine here. To find a headache specialist in your area who can diagnose you and create an effective treatment plan, use our Find a Doctor tool.