Botox for Migraines: How It Works and Who It Helps

For most people, “Botox” means wrinkles. Forehead lines, frown lines, crow’s feet — the cosmetic side. But Botox has a second life that doesn’t get nearly enough attention: it’s one of the most effective preventative treatments we have for chronic migraine. It’s Health-Canada-approved for that purpose. It’s often covered by extended health benefits. And for the right patient, it can be genuinely life-changing.

This guide explains how Botox treats migraines, who qualifies, what the appointment actually looks like, and what to expect in the weeks and months after your first treatment. It’s written for the person who’s been living with chronic migraine, tried the usual medications, and is looking for something different.

The Short Version

Botox is FDA-approved and Health-Canada-approved for the preventative treatment of chronic migraine — which is defined as headache on 15 or more days per month, with at least 8 of those days being migraine days, for at least three months. For patients who meet that definition, Botox injected into specific muscles of the head, face, and neck has been shown to significantly reduce the frequency, intensity, and duration of migraine attacks.

It’s not a treatment for occasional headaches or episodic migraines. It’s not a cure. And it doesn’t help everyone. But for patients who meet the clinical criteria and haven’t responded well to oral preventatives, Botox can reduce migraine days per month by half or more — and often keeps doing so for years.

How Botox Actually Works for Migraine

The short scientific story: Botox blocks the release of certain neurotransmitters — specifically those involved in pain signalling — at the nerve endings it’s injected near. For cosmetic Botox, this means the muscle relaxes and the skin over it stops creasing. For migraine Botox, it means the nerves that feed into the migraine pain pathway get temporarily turned down, and the trigger threshold for a migraine becomes harder to cross.

The exact mechanism is still being researched — we know it works, and we have decades of clinical data showing how effective it is. But the leading theory is that Botox interrupts the release of pain-signalling chemicals (like CGRP and substance P) from nerve endings in the head and neck, essentially “quieting” the nervous system’s tendency to fire off a migraine in the first place.

Botox is a preventative treatment, not a rescue treatment. It doesn’t stop a migraine that’s already starting. It reduces the number and severity of migraines you have over the following three months by changing the baseline activity of the nervous system.

Who Qualifies for Migraine Botox?

The clinical criteria are specific. For Botox to be considered appropriate and likely to be covered by extended health benefits, you should meet the following:

• Chronic migraine diagnosis. This typically means you experience headache on 15 or more days per month, with at least 8 of those days being migraine days, for at least three months.
• You’ve tried oral preventatives first. Most insurance policies require that you’ve trialed two or more oral migraine preventatives (like topiramate, propranolol, or amitriptyline) without adequate relief.
• Your migraines are significantly impacting your life. Missing work, reducing social activity, affecting sleep, limiting exercise, or causing significant distress.

Botox is generally not the right treatment for:

• Episodic migraine (fewer than 15 headache days per month)
• Tension-type headaches alone
• Cluster headaches (different treatment protocols exist)
• New migraines that haven’t been worked up medically (rule out other causes first)

A proper assessment always starts with confirming the diagnosis. Not every severe headache is a migraine, and not every migraine is chronic. The first consultation is about making sure Botox is actually the right tool for your specific headache pattern.

What the Appointment Actually Looks Like

Migraine Botox is administered using a protocol called PREEMPT — the name of the clinical trial that established the effective dose and injection pattern. It’s specific, standardized, and has been the gold standard for over a decade.

Here’s what the appointment involves:

The protocol

A total of 31 small injections, administered across 7 specific muscle groups of the forehead, temples, back of the head, and neck. The injections are shallow, thin-needle, and take about 15 to 20 minutes total. Most patients describe them as tolerable rather than painful — quick pinches rather than anything severe.

The dose

155 units of Botox, distributed across the 31 injection sites according to the PREEMPT pattern. This is a larger total dose than cosmetic Botox, but it’s spread across many more sites.

The schedule

Treatments are repeated every 12 weeks (four times per year). This cadence is important — effect wears off gradually over that window, and consistent re-treatment maintains benefit.

What to Expect in the Weeks After

Migraine Botox doesn’t work overnight, and expectations matter.

Week 1

Little to no change. Some patients actually experience a slight uptick in headaches in the first days after injection as the medication begins to take effect — this is normal and temporary.

Weeks 2 to 4

Onset of effect. You should start to notice migraines that are slightly less severe, slightly shorter, or slightly less frequent. This is the “it might be working” phase.

Weeks 4 to 10

Peak effect. Most patients see their best migraine-day reduction in this window. For responders, the difference is often dramatic — migraine days per month cut in half, attacks that do occur becoming more responsive to rescue medication, significantly better quality of life.

Weeks 10 to 12

Gradual decline as the Botox begins to wear off. Migraines may start returning in frequency. This is the signal that it’s time for the next treatment cycle.

Important note: the PREEMPT clinical data suggests that patients often see the best results after their second treatment, not the first. If your first treatment cycle wasn’t dramatic, it’s worth completing at least two cycles before deciding whether Botox is or isn’t working for you.

Insurance and Coverage in Alberta

Migraine Botox is typically covered by extended health benefits in Canada when clinical criteria are met and your claim is properly documented. Coverage varies by plan, but many patients find their out-of-pocket costs are significantly reduced — or fully covered — when the treatment is billed under the migraine indication rather than cosmetic.

Alberta Health does not currently cover migraine Botox as a standard benefit, but most employer-sponsored extended health plans, private insurance plans, and some spousal coverage plans do cover it. The key to getting coverage is proper documentation — a clear diagnosis of chronic migraine, evidence that oral preventatives were tried first, and a proper referral or assessment.

At Glenmore, we provide the documentation your insurance company typically requires. We can’t guarantee coverage — that depends on your specific plan — but we’ll help you navigate the process.

Our Approach

Migraine Botox is a treatment we take seriously — not a quick add-on to our cosmetic menu. Our clinic is physician-led, with over 30 years of family medicine experience in Calgary, and our clinical focus has long included migraine management alongside medical aesthetics and weight loss medicine.

What that means practically:

• Your first appointment is a full clinical assessment, not a quick injection visit
• If Botox isn’t the right tool for your headache pattern, we’ll tell you — and point you toward what is
• Documentation for insurance is taken care of as part of the protocol
• Follow-up between treatments is expected, not optional — we track what’s working and adjust if it isn’t

We also use standard Botox for cosmetic purposes, so patients who have both migraine and aesthetic goals can often coordinate their treatment plan in a way that’s clinically and financially efficient. If you’re curious about what cosmetic Botox actually treats — and how it compares to dermal fillers — our Botox vs filler decision guide covers the differences.

Common Questions

Will it change how my face looks?

Some. Because the protocol includes injections in the forehead and temples, you may notice softer forehead lines or reduced frown movement. Most patients find this either neutral or positive. It’s not the goal, but it’s a common side effect.

Is it painful?

The injections are small and quick. Most patients rate them as mildly uncomfortable — similar to getting several thin-needle shots in a row. The 15- to 20-minute appointment is well-tolerated by the vast majority of patients.

What if it doesn’t work?

Some patients don’t respond to migraine Botox. That’s the honest reality of any preventative treatment. We recommend completing at least two full cycles (six months) before making a final decision, because responders often see their best effect after the second treatment. If Botox isn’t the right tool for you, we can discuss other preventative options or referral pathways.

Can I also get cosmetic Botox?

Yes. Cosmetic and migraine Botox can be coordinated in the same practice. The cosmetic dose is often smaller than the migraine dose and can sometimes be incorporated into the same treatment cycle.

How soon will I know if it’s working?

You should see some improvement by week 2 to 4 of your first treatment, and peak effect by week 4 to 10. If you haven’t seen any change after your first full 12-week cycle, that’s worth discussing — but it doesn’t necessarily mean it won’t work after a second cycle.

The Bottom Line

If you’ve been living with chronic migraine for months or years, tried oral preventatives without success, and feel like your treatment options have run out — migraine Botox is worth a conversation. For the right patient, it’s one of the most effective tools we have. For the wrong patient, it’s not, and we’ll tell you so.

The Glenmore Clinic is located at 1600 90 Ave SW, Suite A305, in Calgary. You can reach us at 403.452.5699 or book a consultation online. We’ll take the time to understand your specific migraine pattern before recommending anything — because the best migraine treatment starts with knowing exactly what you’re dealing with.