Botox (onabotulinumtoxinA) is a preventive therapy for adults with chronic migraine, a debilitating neurological condition associated with frequent and severe headaches. Botox treatment involves an experienced healthcare provider injecting small doses of a bacteria-derived toxin into specific areas of the face, head, and neck.

Scientific evidence supports Botox as a safe, well-tolerated, and effective treatment option for chronic migraine. Nevertheless, potential side effects include neck pain and, ironically, headache or worsening migraine. The effect of Botox is temporary, typically requiring repeat injections every 12 weeks.

The Food and Drug Administration (FDA) approved Botox in 2010 to prevent chronic migraines (15 or more headache days per month) in adults. It is not approved for preventing episodic migraine, which is 14 or fewer headaches a month.

Botox was evaluated in two scientific studies to obtain FDA approval. The studies revealed that participants receiving the Botox injections had 7.8 to 9.0 fewer headache days per month. This was statistically significant compared to the placebo (inactive treatment) group.

Pooled data from the two studies also revealed benefits, such as reduced headache-related disability and improved health-related quality of life in the treatment group. Since its FDA-approval, Botox has been shown to be effective for chronic migraine.

How Long the Benefits Last

Botox’s effect is temporary, lasting around three months. Therefore, the recommended treatment schedule is every 12 weeks, equivalent to four treatments yearly.

Undergoing Botox injections is a relatively quick procedure, lasting around 20 minutes. Most people can return to their daily activities immediately afterward.

During the procedure, a neurologist (physician specializing in nervous system disorders) injects Botox into 31 different sites of the face, head, and neck. The FDA recommends a total dose of 155 units, with five units per site.

These sites include:

• Above the bridge of the nose
• Forehead
• Temples
• Back of the head
• Top of the neck
• The muscles in the upper back/neck area (trapezius muscles)

After the injections, the Botox takes 10 to 14 days to take optimal effect.

Side Effects

The most commonly reported side effects following Botox injections for chronic migraine are neck pain and headache. Paradoxically, migraine is also reported as a potential side effect of Botox.

In the preapproval studies mentioned previously, neck pain occurred in 9% of people receiving Botox injections for chronic migraine, whereas 3% of people undergoing placebo reported neck pain.

Of people undergoing Botox. 5% reported headache, and 4% reported migraine, compared to 3% reporting these in the group receiving a placebo treatment. Experts suspect that after receiving Botox, it’s possible that the targeted muscle spasms before relaxing, triggering a temporary headache.

Injury to a blood vessel, the needle erroneously hitting the membrane covering bone, or anxiety and stress over the procedure itself could also perhaps lead to a headache.

Other potential side effects of Botox include:

• Facial paralysis (facial weakness/impaired movement)
• Eyelid drooping (ptosis)
• Bronchitis (swelling of the tubes that deliver air into the lungs)
• Muscle stiffness/aching/weakness/spasms
• Injection site pain
• Hypertension

Less frequently (less than 1% of people undergoing Botox for chronic migraine) reported side effects included;

• Vertigo (sensation of spinning)
• Dry eye
• Eyelid swelling
• Trouble swallowing (dysphagia)
• Eye infection
• Jaw pain

Allergic reactions, including the potentially life-threatening one known as anaphylaxis, can occur with Botox. In such cases, the reaction should be treated and the medication not used again.

Due to the potential for serious side effects such as the toxin spreading from the injection site, Botox was given a boxed warning, the strongest warning the FDA can issue.

Symptoms of botulinum toxin poisoning have been reported hours to weeks after injection. They may include muscle weakness felt all over the body and breathing difficulties, among other neurological symptoms.

However, when administered at the advised doses for chronic migraine, the FDA states that there have been no definitive reports of Botox toxin spread.

Who Should Consider It

You may be a good candidate for Botox injections if you are an adult with chronic migraine.

Chronic migraine is defined as headaches that occur 15 or more days per month for more than three months, and these headaches have features of a migraine (migrainous features) on at least eight days per month.

Examples of migrainous features include headaches that are:

• Located on one side of the head
• Throbbing and moderate to severe in intensity
• Worsened by physical activity
• Accompanied by symptoms like sensitivity to light/sound/smell, nausea, and vomiting

Keep in mind that Botox is only one option for preventing chronic migraine. Other medical therapies, include:

Cost and Insurance

According to the American Migraine Foundation, the cost of undergoing Botox injections for chronic migraine can range from about $300 to $600.

Since Botox is FDA-approved for chronic migraine, it’s covered by most insurance plans, including Medicare and Medicaid.

Depending on your insurance plan, you may have to pay a co-pay. Also, before Botox approval, you may have to try one or more oral (by mouth) medicines for chronic migraine prevention (listed above).

Summary

The FDA has approved Botox for the prevention of chronic migraines. Botox works by relaxing injected muscles and blocking the release of inflammatory proteins that usually transmit pain signals associated with migraine headaches.

Numerous studies have proven Botox’s benefits in reducing headache days per month and improving quality of life. Botox also has a strong safety profile, causing few side effects, especially compared to other migraine preventive medications.

It’s important to understand that there is no single best treatment plan for managing chronic migraine. Speak with a neurologist or headache specialist about whether Botox is a potential and reasonable therapy for your migraine care.