Botox for Chronic Migraine: The Protocol, the Criteria and the Cost
Reviewed for medical accuracy against our Medical Review Board · Last updated 19 August 2026
Part of Medical Botox: Every Therapeutic Use
Botox for chronic migraine is 155 units given across 31 fixed injection sites, every 12 weeks, and it is only approved for people with 15 or more headache days a month. It is a preventive treatment. It does nothing for a migraine you already have.
This is the one use of Botox on this site that is a medical treatment rather than a cosmetic one. It has been FDA approved since 2010, it has a fixed published protocol, and it is usually paid for by insurance. Almost everything that follows is different from the cosmetic treatments, including who should be holding the needle.
1. The 15-day gate, and why most people are turned down
The approved indication is narrow and precise. Botox is indicated for the prevention of headaches in adults with chronic migraine, and chronic migraine has a definition: 15 or more headache days a month, with headaches lasting four hours a day or longer.
That threshold is the whole ballgame, and it is where most enquiries end.
14 days is not 15. Fewer than 15 headache days a month is episodic migraine. Botox is not approved for it, the trials were not run on it, and an insurer will decline it. This is not your doctor being obstructive. It is the line the approval draws.
The practical consequence: keep a headache diary before your appointment, not after. Dates, duration, and whether it was a headache day at all. A neurologist cannot certify 15 days a month from memory, and a vague history is the most common reason a request fails at the insurance stage rather than the clinical one. Three months of records is the usual expectation.
2. The full protocol: 155 units, 31 sites
Unlike cosmetic treatment, where dosing is a judgement call, this protocol is fixed. It comes from the PREEMPT trials, two Phase III studies of 1,384 adults that supported the 2010 approval, and it is the reason your treatment should look the same in Denver as in Chicago.
| Muscle group | Units | Sites | Where that is |
|---|---|---|---|
| Frontalis | 20 | 4 | The forehead |
| Corrugator | 10 | 2 | Between the brows, one each side |
| Procerus | 5 | 1 | The bridge of the nose |
| Temporalis | 40 | 8 | The temples, the largest share |
| Occipitalis | 30 | 6 | The back of the head |
| Cervical paraspinal | 20 | 4 | The back of the neck |
| Trapezius | 30 | 6 | The tops of the shoulders |
| Total | 155 | 31 | Every 12 weeks |
Two things worth noticing. The temples take the largest share at 40 units, more than twice the forehead. And more than half the total, 80 of the 155 units, goes into the back of the head, the neck and the shoulders rather than the face.
Some prescribers add further injections beyond the 155 units, following where a particular patient's pain actually sits. That is a recognised approach and the labeling allows for it, but the fixed 155 is the starting point rather than a menu.
For comparison, a whole forehead treated cosmetically takes about 20 units. This is nearly eight times that dose. Our units guide and calculator sets out the cosmetic figures for every area.
3. Chronic or episodic, and why the line is drawn at 15 days
This is the fact that decides whether any of this applies to you, and it is a number rather than a judgement.
The label indicates Botox for the prophylaxis of headaches in adults with chronic migraine, defined as 15 or more headache days a month with headaches lasting four hours a day or longer. Fourteen days or fewer is episodic migraine, and for that the label carries an explicit Limitation of Use.
Read the wording of that limitation, because it is stronger than it first looks. Safety and effectiveness have not been established for the prophylaxis of episodic migraine in seven placebo-controlled studies. That is not an untested gap. Seven trials were run and the indication did not follow.
So the practical position:
- 15 or more headache days a month. You are inside the indication, and the 155 unit protocol described above is what was studied.
- 14 or fewer. You are outside it. Treatment may still be offered and may still help you, but it is off-label use of a drug that was specifically trialled in your situation and did not meet its endpoint.
Count before your consultation. A headache day is a day with any headache, not only the disabling ones, and most people who have never counted are surprised in one direction or the other. If you are close to the boundary, a month of honest recording is worth more to the conversation than an estimate.
One thing this does not mean: that 14 days of migraine is not serious. It means this particular treatment does not have evidence behind it for that pattern, and the discussion should be about what does.
4. It is prevention, not rescue
This is the most expensive misunderstanding in the subject, so it is worth being blunt.
Botox does not treat a migraine you currently have. It will not shorten an attack, it is not a painkiller, and being injected during an attack is not how it works. It is prophylaxis: a treatment given on a schedule to make future attacks less frequent. Your rescue medication stays exactly as it is.
The measure of success is also not what most people expect. It is not "no more migraines". It is fewer headache days per month than you were having before. The PREEMPT trials showed a significantly greater reduction in headache days than placebo, which is what the approval rests on. A treatment that takes you from 20 headache days to 12 is working, even though you still get migraines.
Going in expecting elimination is the fastest route to concluding a treatment failed when it did not.
5. Why it goes into your neck and shoulders
Patients are routinely surprised to be asked to sit forward so their shoulders can be injected. It is worth understanding why, because it is not padding.
Chronic migraine pain does not respect the boundary between head and neck. The nerves carrying sensation from the upper neck and the back of the head converge with those carrying sensation from the face and front of the head, and pain in one region is commonly felt in the other. Treating the occipital, cervical and trapezius groups addresses that whole territory rather than just the part of your head that hurts most.
So a protocol that treats only your forehead is not the approved protocol, whatever it is being called. If a provider offers "Botox for migraines" and injects only the face, ask which protocol they are following.
6. What to expect, and why you need two cycles
- The appointment takes roughly 15 to 20 minutes. Thirty-one injections sounds worse than it is, because each one is a very small volume through a fine needle.
- Onset is gradual. Expect two to four weeks before you can judge anything, not days.
- Every 12 weeks. Not "when it wears off". The schedule is part of the protocol.
- Two cycles before deciding. This is the part most worth knowing: benefit typically builds across treatments, and the second cycle often does more than the first. Abandoning after one round is the most common way people conclude it does not work for them.
Here is what the two trials behind the approval actually found. Both ran 24 weeks over two injection cycles, in adults with more than 15 headache days a month who were taking no other preventive medicine.
| Per 28 days | Study 1: Botox (n=341) | Study 1: placebo (n=338) | Study 2: Botox (n=347) | Study 2: placebo (n=358) |
|---|---|---|---|---|
| Headache days | 7.8 fewer | 6.4 fewer | 9.2 fewer | 6.9 fewer |
| Hours of headache | 107 fewer | 70 fewer | 134 fewer | 95 fewer |
The placebo groups, injected with saline, improved by 6.4 and 6.9 headache days a month. The treated groups improved more, but the share attributable to the drug is the gap between the columns: 1.4 fewer headache days in the first trial and 2.3 in the second. Both differences were statistically significant, and both are a good deal smaller than the reductions usually quoted at you.
Counted in hours rather than days it reads better. The treated groups lost 37 and 39 more hours of headache per 28 days than placebo did, which is roughly a day and a half of headache removed every month. If you are starting from 20 or more headache days, that is a real change. It is simply not the transformation the before-and-after stories imply, and knowing the true size of it in advance is what stops people abandoning a treatment that is working as well as it is ever going to.
One detail worth asking about: patients in both trials received 155 to 195 units, not a flat 155. The dosing section of the label specifies the fixed 155-unit, 31-site pattern, so if your injector plans to go above it, ask what the extra units are for and where they are going.
Keep the diary going. You will be asked whether it helped, and "I think so" is a weak answer both clinically and to an insurer deciding whether to keep paying. Counted headache days before and after is the evidence that keeps your treatment approved.
7. Insurance: the one that usually is covered
Every other use of Botox on this site is either cosmetic and never covered, or off-label and usually declined. This one is different: it is an approved indication for a recognised medical condition, and coverage is normal rather than exceptional.
What insurers generally want to see:
- A chronic migraine diagnosis from a physician, typically a neurologist or headache specialist.
- Documented 15 or more headache days a month. Your diary.
- Failed preventive medications. Usually at least two different classes tried and either ineffective or not tolerated. This is the step people skip, and it is the one that generates denials.
- Prior authorisation before the first treatment.
- Documented benefit to keep it approved after the first cycles.
Contrast this with masseter Botox for clenching and grinding, where the same drug in a lower dose is off-label and insurers decline it almost as a matter of routine. The difference is not the medicine. It is whether an approved indication exists.
8. Who should be injecting this
This is not a med spa treatment, and that is the clearest line on the whole site.
Chronic migraine needs diagnosing before it needs treating, which requires a physician who can rule out the other causes of frequent headache. The injections themselves cover the back of the head, the neck and the shoulders, which is anatomy most aesthetic injectors never work in. And the paperwork that gets it paid for is neurology paperwork.
In practice this means a neurologist or headache specialist, or a clinician working directly in that setting. If an aesthetic clinic offers migraine Botox, the questions are who made the diagnosis, which protocol they use, and whether they inject the neck and trapezius at all. Whoever treats you, you can confirm they hold a current license for free, and we list the lookup for every state in how to verify a Botox injector's license.
9. What it costs if you pay cash
Most people will not pay this, because insurance covers it. But the number is worth seeing, both because some people are declined and because it shows what the insurer is actually funding.
| Published rate | Per unit | 155 units |
|---|---|---|
| Lowest we found | $9 | $1,395 |
| Middle of the range | $12 | $1,860 |
| Highest we found | $18 | $2,790 |
These are rates clinics actually publish, read off their own price pages rather than estimated: the floor is $9 a unit in Atlanta, GA and the ceiling $18 in Tampa, FL. Your own city may sit outside that range entirely. We check published pricing city by city, and the locations index lists every city covered so far, with the named clinics and their rates.
That is per treatment, four times a year. It is the most expensive Botox treatment there is by a wide margin, which is exactly why the insurance route in section 6 matters more here than anywhere else. Our Botox price guide covers how per-unit pricing works.
10. Side effects at 155 units
A larger dose in more places brings its own pattern, and it is not the cosmetic pattern:
- Neck pain and stiffness, the most commonly reported complaint with this protocol. It reflects where the injections go.
- Neck weakness. Some people notice their head feels heavier, particularly leaning forward. It comes from treating the cervical and trapezius groups and it eases as the effect wears off.
- Injection-site soreness across the scalp and shoulders for a day or two.
- Eyelid drooping, from the forehead and glabellar part of the pattern, exactly as in cosmetic treatment.
- Headache after treatment, which is a genuinely unwelcome irony and usually short-lived.
The label puts numbers on these, from 687 treated patients against 692 on placebo. Two things are worth noticing: most of these complaints also occurred in the placebo group, and neck pain is the one that genuinely separates.
| Reaction | Botox, 155 to 195 units (n=687) | Placebo (n=692) |
|---|---|---|
| Neck pain | 9% | 3% |
| Headache | 5% | 3% |
| Migraine | 4% | 3% |
| Eyelid drooping | 4% | under 1% |
| Muscle stiffness | 4% | 1% |
| Muscle weakness | 4% | under 1% |
| Bronchitis | 3% | 2% |
| Muscle ache | 3% | 1% |
| Musculoskeletal pain | 3% | 1% |
| Injection site pain | 3% | 2% |
| Facial weakness | 2% | 0% |
| Muscle spasms | 2% | 1% |
| Raised blood pressure | 2% | 1% |
Below 1 percent, and more often than placebo, the label also lists vertigo, dry eye, eyelid swelling, difficulty swallowing, eye infection and jaw pain.
The one that rarely gets mentioned. In these same two trials, severe worsening of migraine bad enough to require hospital admission happened to about 1 percent of treated patients against 0.3 percent on placebo, usually within the first week after treatment. It is uncommon, but it is a documented outcome of a treatment given to prevent headaches, and it is better to know it exists before your first cycle than during it.
There is no reversal agent, so anything that does occur resolves on its own over weeks to months. Report new or worsening symptoms to the prescribing physician rather than waiting for the next cycle.
11. The cosmetic side effect nobody mentions
Look at the protocol table again. It includes 20 units in the frontalis, 10 in the corrugators and 5 in the procerus, which is 35 units across exactly the muscles treated cosmetically for forehead lines and frown lines.
So migraine treatment will soften your forehead and frown lines whether or not that is why you came. Most patients are pleased. Some are not, particularly if the brow feels heavy, which is the same mechanism described in the forehead guide: the frontalis is the only muscle that lifts the brow.
Two honest notes. It is not a reason to seek migraine treatment, and it is not a reason to describe cosmetic treatment as migraine treatment to an insurer. It is simply a consequence of the protocol that you should know about in advance rather than discover in a mirror.
12. What to ask before you agree
- Do my records show 15 or more headache days a month? Settle this before anything else.
- Do you use the full 155-unit protocol, including the neck and trapezius?
- Which preventive medications do I need to have tried first for my insurer?
- Who submits the prior authorisation, and what happens if it is declined?
- When should I judge whether this is working, and what counts as working? A good answer involves two cycles and a count of headache days.
- What should I do if my neck feels weak afterwards?
And keep the diary. It is the cheapest, most useful thing you can bring to every appointment in this treatment.
The other one insurance pays for. Botox for severe underarm sweating is the only other common use with a clear route to coverage, and it clears the same kind of gate: a documented failure of the first-line treatment before the injection is considered.
Frequently asked questions
How many units of Botox for migraines?
Do I qualify for Botox for migraine?
Does Botox stop a migraine once it has started?
Why does Botox for migraine go into the neck and shoulders?
Is Botox for migraine covered by insurance?
How long before Botox helps my migraines?
How much does Botox for migraine cost without insurance?
Will migraine Botox change how my face looks?
Does Botox work for episodic migraine?
How many headache days do you need for Botox?
Sources
Every figure on this page was read from the documents below rather than from a clinic or a manufacturer's marketing. They open in a new tab so you can check any claim here against its source.
- BOTOX prescribing information, therapeutic indications, FDA via DailyMed
- OnabotulinumtoxinA injection, MedlinePlus, US National Library of Medicine
