Frequent headache can slowly become the structure of a month.
Plans are made around it. Work is rearranged. Tablets stay close. A good day may be used to recover from the last attack or prepare for the next one.
There are treatments that can reduce that burden. The useful questions are how much they help, how long to give them, and which option fits the pattern you are living with.
This article explains chronic migraine, the results of preventive injection treatment, and how that treatment is accessed through the NHS.
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Recognising chronic migraine
Frequent headaches deserve a diagnosis and a prevention plan.
Could this be chronic migraine?
Headache on at least 15 days a month, with migraine features on at least eight, for more than three months is the pattern used to identify chronic migraine. Some of those days can feel milder or more like pressure than a familiar migraine attack. [1]
Migraine may bring nausea, sensitivity to light or sound, and pain that worsens with movement. Aura can occur, but it is not needed for the diagnosis. A clinician also checks whether another cause could explain the headaches. [7]
If you have fewer than 15 headache days, treatment can still be worthwhile. The options depend on the diagnosis and how much the attacks disrupt your life; the chronic-migraine threshold is not a reason to put up with disabling symptoms. [1]
What treatment is trying to change
Medicines taken during an attack aim to relieve that episode. Preventive treatment aims to reduce the number or burden of future attacks. A plan may include both. [7]
Depending on your health and previous treatment, prevention may involve tablets, acupuncture, medicines targeting CGRP (a substance involved in migraine), or botulinum toxin injections. Your medical history, other medicines and pregnancy plans affect which options are suitable. [1]
I would want to know how many days you lose, what you have already tried and what happened with each treatment. “It did not suit me” might mean it did not help, caused side effects, or could not be used safely. Those are different reasons for choosing the next option.
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What treatment can change
Results from large studies, with the comparison kept visible.
How preventive injections work
Botulinum toxin treatment for chronic migraine acts on nerve signalling involved in pain. The aim is fewer headache days. It is different from using injections to soften a facial line, even though the medicine may be familiar from aesthetic treatment. [6]
What did the largest trials find?
The two PREEMPT trials included 1,384 adults. Participants started with about 20 headache days in every 28. They received either onabotulinumtoxinA (a preparation of botulinum toxin A) or saline placebo injections, with results compared at 24 weeks after two treatment cycles. [2]
Medicine compared with saline placebo.
People in every 100, rounded from 47.1% and 35.1%.
That is about 12 additional people in every 100 reaching the halving target with the medicine. The average difference between groups was 1.8 headache days per 28 days. Some people improved considerably; others did not reach that target. [2]
The improvement in the placebo group means the full 8.4-day reduction cannot be attributed to the medicine alone.
What does the wider evidence add?
A Cochrane review included 28 trials and 4,190 people across migraine types. For chronic migraine, four trials involving 1,497 people estimated 3.1 fewer migraine days per month than placebo at 12 weeks. Removing small trials left the two PREEMPT studies: 1,384 people and a more conservative two-day difference (estimated range 1.1–2.8; moderate-certainty evidence). Most participants in the review came from manufacturer-funded trials. [8]
This counts migraine days at 12 weeks. The figures above count all headache days at 24 weeks in the same participants. They should not be added together or treated as independent confirmation. The review searched evidence available up to December 2017. [8]
Can improvement continue with repeated treatment?
In COMPEL, 716 adults started a course of treatment repeated every 12 weeks. Average headache frequency fell from 22 days per 28 days to 11.3 at 108 weeks: 10.7 fewer days. [3]
Only 373 people completed the study, there was no placebo group, and the analysis estimated some missing results. It suggests that benefit can continue during a repeated course. It does not mean one treatment lasts two years, or that everyone who starts will obtain that result. [3]
Both PREEMPT and COMPEL were manufacturer-funded. PREEMPT provides the stronger comparison for deciding how much benefit the medicine adds; COMPEL helps describe longer-term use. [2][3]
How does it compare with other prevention?
The choice also includes oral preventive medicines and treatments targeting CGRP, including some tablets, injections and infusions. NHS eligibility differs between medicines and between episodic and chronic migraine. Your previous treatment, other health conditions and preferences help determine the next option. [1]
In the FORWARD trial, 56 of 140 people allocated to botulinum toxin (40%) achieved at least a halving of headache days during weeks 29–32, compared with 17 of 142 allocated to topiramate (12%). However, 120 of 140 completed the assigned injection treatment and only 28 of 142 completed topiramate; people taking topiramate could switch to injections. Missing results were counted as a return to the starting headache frequency. Participants knew their treatment, and the manufacturer funded the study. These results reflect whether people could stay on treatment as well as whether it helped. [9]
The Italian RAMO study observed larger reductions with three CGRP antibody medicines: at 12 months, average monthly headache days had fallen by 11.9 among 69 people receiving antibodies and 7.6 among 85 receiving botulinum toxin. Treatment was not randomly assigned. Among all 183 people originally enrolled, the toxin group began with more headache days (21.7 versus 18.7), and the groups started treatment in different years. The study had public funding; several authors disclosed industry relationships. These observations cannot establish that antibodies are the better choice for an otherwise comparable patient, and do not cover every CGRP treatment. [10]
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The NHS pathway
Who qualifies, what is reviewed, and what to record.
Who qualifies through the NHS?
For adults in England, NICE recommends botulinum toxin as an option when chronic migraine has been diagnosed, at least three preventive medicines have not helped, could not be tolerated, or were unsuitable for safety reasons, and medication overuse is appropriately managed. [1]
You do not have to take a medicine that is unsafe for you simply to count it as a failed treatment. Keep a record of each medicine, how long you used it and why it was stopped.
What counts as enough improvement?
NICE recommends stopping this treatment if headache days have fallen by less than 30% after two cycles, or if the pattern has changed to fewer than 15 headache days a month for three consecutive months. [4]
For example, a change from 20 headache days to 14 is a 30% reduction. The NHS continuation threshold is therefore different from the 50% target reported in the trial above. Your clinician uses your diary to make that comparison.
How to start the NHS pathway
Your GP can review the diagnosis and previous prevention, then arrange specialist assessment where needed. University Hospitals Sussex describes its injection service as a consultant-referred headache-team service. A private consultation does not itself establish NHS eligibility or replace that referral. [5][7]
NHS funding criteria and an individual prescribing decision are separate. If you do not meet the criteria for this particular treatment, other migraine care may still be appropriate.
The record that helps most
A diary covering at least eight weeks helps show frequency and response. Record headache days, severity and duration, migraine symptoms, medicines taken and their effect, and menstrual timing where relevant. [1]
Count milder headache days as well as the attacks that stop you working.
Include prescriptions and anything bought over the counter.
Note missed work, interrupted sleep or plans you could not keep.
Frequent use of medicines taken during attacks can itself worsen headache. NICE highlights use for three months or more on at least 10 days a month for triptans, opioids or combination painkillers, or 15 days for paracetamol, aspirin or anti-inflammatory painkillers. Ask your clinician to plan any changes, particularly if opioids are involved. [1]
What if medication overuse is part of the pattern?
A publicly funded Dutch trial studied 179 people with chronic migraine and medication overuse. Everyone followed a supervised withdrawal programme. Adding botulinum toxin did not show a clear extra benefit over the comparison injections during the first 12 weeks: headache days fell by 26.9% and 20.5%, respectively. The uncertainty around the difference included no additional benefit. [11]
This was a specific treatment setting and only one injection cycle; people using opioids were excluded. The comparison group also received a small forehead dose to help conceal treatment allocation. The result does not prove that the medicine never helps people with medication overuse. It shows why the withdrawal plan deserves attention rather than assuming injections will resolve the whole problem. Arrange changes with your clinician; this trial is not a guide to stopping medicines on your own. [11]
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Living with treatment
Timing, side effects and the signs that need urgent help.
What happens during a course?
The established migraine protocol uses 31 small injections across the head and neck, with additional sites possible. Treatments are usually 12 weeks apart. This is a planned course with reviews, rather than an injection to stop an attack already underway. [5]
The Sussex NHS leaflet advises that benefit may begin after two to three weeks; some people notice benefit only after the second treatment. Keep the diary going through both cycles so an early difficult week does not decide the whole assessment. [5]
How often were side effects reported?
| Reported symptom | Medicine 687 people | Saline placebo 692 people |
|---|---|---|
| Neck pain | 46 (6.7%) | 15 (2.2%) |
| Muscle weakness | 38 (5.5%) | 2 (0.3%) |
| Drooping eyelid | 23 (3.3%) | 2 (0.3%) |
| Injection-site pain | 22 (3.2%) | 14 (2.0%) |
Side-effect records covered 687 people given the medicine and 692 given placebo. One person could report more than one symptom. [2]
Most adverse effects in PREEMPT were mild or moderate and resolved without lasting consequences. The paper does not give a single recovery time or a detailed severity breakdown for each symptom. Treatment was stopped because of adverse effects by 26 of 687 treated participants (3.8%), compared with 8 of 692 receiving placebo (1.2%). [2]
For practical timing, the Sussex NHS leaflet says neck or shoulder stiffness usually settles within two to three weeks. That is local aftercare guidance, not the measured recovery time of every person in PREEMPT. [5]
When another plan is needed
Injection-site infection and an allergy to the medicine are reasons not to give it. Pregnancy, breastfeeding, existing swallowing problems and conditions affecting nerve–muscle function need particular consideration. The medicine is not recommended during pregnancy, and breastfeeding use cannot be recommended because information is insufficient. [6]
New difficulty breathing, swallowing or speaking after injections needs immediate medical help. These symptoms can indicate effects of the medicine beyond the injected area. [6]
When a headache needs urgent help
- Call 999: sudden, extremely severe headache, or headache with new one-sided weakness, difficulty speaking, loss of vision, seizure, confusion or marked drowsiness.
- Seek urgent GP advice or NHS 111: an attack lasting over 72 hours, aura lasting over an hour, or migraine during pregnancy or soon after giving birth.
A new or substantially changed headache should be assessed rather than assumed to be your usual migraine. [7]
What I would look for at review
The diary should show whether there are fewer headache days, whether the remaining attacks are easier to manage, and whether any side effects outweigh the improvement. I would also ask about the days you can work, make plans and keep them. A useful treatment should make a difference to the month you actually live.
References
[1] NICE. Headaches in over 12s: diagnosis and management (CG150). Recommendations, updated June 2025. Read source ↗
[2] Dodick DW, Turkel CC, DeGryse RE, et al. PREEMPT pooled randomised, placebo-controlled results. Headache. 2010;50:921–936. doi:10.1111/j.1526-4610.2010.01678.x. Read source ↗
[3] Blumenfeld AM, Stark RJ, Freeman MC, Orejudos A, Manack Adams A. COMPEL: long-term efficacy and safety. J Headache Pain. 2018;19:13. doi:10.1186/s10194-018-0840-8. Read source ↗
[4] NICE. Botulinum toxin type A to prevent chronic migraine headaches (TA260): information for the public. Read source ↗
[5] University Hospitals Sussex NHS Foundation Trust. Botox treatment for migraine. June 2024; review due June 2027. Read source ↗
[6] AbbVie. BOTOX 100 Allergan Units: UK Summary of Product Characteristics. Updated on emc 15 May 2026. Read source ↗
[7] NHS. Migraine. Reviewed 10 March 2026. Read source ↗
[8] Herd CP et al. Botulinum toxin injections for preventing migraine in adults. Cochrane Database of Systematic Reviews. 2018; CD011616. Public evidence summary. Read source ↗
[9] Rothrock JF et al. FORWARD: onabotulinumtoxinA versus topiramate in chronic migraine. Headache. 2019;59:1700–1713. doi:10.1111/head.13653. Read source ↗
[10] Grazzi L et al. RAMO: real-world comparison of anti-CGRP monoclonal antibodies and onabotulinumtoxinA. J Headache Pain. 2024. doi:10.1186/s10194-024-01721-6. Read source ↗
[11] Pijpers JA et al. Acute withdrawal and botulinum toxin A in chronic migraine with medication overuse: a double-blind randomised controlled trial. Brain. 2019;142:1203–1214. doi:10.1093/brain/awz052. Read source ↗
Sources checked 13 October 2026; additional evidence checked 16 October 2026. The original trials and Sussex NHS leaflet were read in full. For the additions, the Cochrane public summary and full-text methods, results and limitations of references 9–11 were checked. This is a focused evidence review, not a systematic review.
