Botox (onabotulinumtoxinA) is a preventive for chronic migraine, defined as headache on 15 or more days a month. If you have migraine four times a month, this is not your treatment, and the trials say so.
That distinction is the whole article. It is also the thing most often skipped over when the treatment is offered.
The protocol is fixed, and that is deliberate
The evidence rests on a specific injection plan from the PREEMPT clinical program: 155 units delivered as 31 fixed-site, fixed-dose injections across seven head and neck muscle areas, repeated every 12 weeks.1 The clinician may add another 40 units using a follow-the-pain approach (placing them where the pain is), up to a maximum of 195 units.1
PREEMPT 1 and 2 together enrolled 1,384 people with chronic migraine. They had a 24-week double-blind, placebo-controlled phase, followed by a 32-week open-label phase.1,2
It is worth knowing the protocol is standardized, not improvised, because that is what the evidence describes. Cosmetic Botox is a different treatment: different sites, different dose, different purpose. A cosmetic injection pattern will not treat migraine.
Why episodic migraine is excluded
This is not a technicality or an insurance obstacle. Trials in people with fewer than 15 headache days a month did not show benefit. That is why the indication is written the way it is. If you are below that threshold, the honest answer is that Botox is unlikely to help you, and there are better options.
Counting matters, then. Not an estimate — an actual calendar, for a month, marking every day you had any headache at all. Most people are surprised in one direction or the other. See headache prevention.
What the appointment is like
The needles are very fine and the injections are shallow, into muscle across the forehead, temples, back of the head, neck and shoulders. The whole appointment takes around fifteen minutes. There is no sedation and you drive yourself home.
Common after-effects are neck stiffness and soreness at the injection sites for a few days. Temporary eyelid or brow droop happens in a small minority and goes away. It is avoided in pregnancy and in some neuromuscular conditions.
Honest expectations
The effect builds. Most people who respond do not respond fully to the first round. Benefit typically adds up over two to three cycles. That means roughly six months before you and I can say whether this works for you. Planning for one round and a verdict is planning to be disappointed.
It reduces headache days rather than ending them. A meaningful response is a large cut in how often they come, not a cure. And it is a preventive, not a rescue: it will not stop the attack you are having today. For that, see IV migraine therapy.
The thing to rule out first
A great many people who meet the 15-day threshold are in a medication-overuse cycle. In that cycle, daily acute treatment keeps the daily headache going. Treating that first sometimes drops the frequency below the chronic threshold on its own.
Starting an expensive preventive to fight a problem the medicine cabinet is creating is a poor use of both. We ask about this before we inject.
Common questions
How many headache days a month do I need?
Fifteen or more, of which at least eight have migraine features, for more than three months. Bring a month of counted days rather than an estimate — see Botox for chronic migraine.
How long before I know if it works?
Plan on two to three cycles, roughly six months. Benefit builds up rather than arriving all at once. Judging it on one round is the most common mistake. See Botox for chronic migraine.
Is this the same as cosmetic Botox?
No. The sites, the dose and the purpose are different. A cosmetic pattern does not treat migraine, and the migraine protocol is not a cosmetic treatment. See Botox for chronic migraine.
Can I have Botox and nerve blocks?
They do not rule each other out, and they serve different roles — one preventive, one targeted and often diagnostic. Which combination fits depends on your pattern; see occipital nerve block.
What if I have fewer than 15 headache days?
Then Botox is not indicated, and we will say so. The conversation moves to acute treatment and to prevention that fits episodic migraine — see migraine treatment.
Botox is for chronic migraine, meaning headache on 15 or more days a month, and it is one tool in our migraine treatment in St. Louis. The Botox for chronic migraine page covers the injection schedule.
Sources
- Dodick DW, Turkel CC, DeGryse RE, et al. OnabotulinumtoxinA for treatment of chronic migraine: pooled results from the double-blind, randomized, placebo-controlled phases of the PREEMPT clinical program. Headache. 2010;50(6):921–936. PMID 20487038. pubmed.ncbi.nlm.nih.gov
- Aurora SK, Dodick DW, Turkel CC, et al. OnabotulinumtoxinA for treatment of chronic migraine: results from the double-blind, randomized, placebo-controlled phase of the PREEMPT 1 trial. Cephalalgia. 2010;30(7):793–803. journals.sagepub.com