The 2026 AAN/AHS guideline gives a practical framework for when to start preventive therapy, which drugs to consider, and how to individualize treatment in adults with migraine. The key shift is toward earlier, structured, patient-centered prevention rather than waiting until migraine becomes highly disabling.
When should preventive therapy be offered?
Preventive treatment should be offered when migraine is frequent or disabling. The guideline uses a practical threshold: ≥4 migraine days/month or ≥4 moderate-to-severe headache days/month. It should also be offered when migraine causes substantial disability, even if the number of monthly attacks is lower.
| Offer prevention when | Why it matters |
|---|---|
| ≥4 migraine days/month | Frequency supports prevention |
| ≥4 moderate-to-severe headache days/month | Severity matters |
| Substantial disability | Function matters |
How should the preventive drug be chosen?
There is no single “best” preventive for every patient. The guideline recommends choosing treatment through shared decision-making, considering efficacy evidence, adverse effects, comorbidities, contraindications, cost, pregnancy potential, and patient preference.
The practical question is: which preventive best fits this patient?
Which drugs have stronger evidence?
For patients without major comorbidities or contraindications, the guideline highlights the following higher-confidence options.
| Episodic migraine | Chronic migraine |
|---|---|
| Atogepant | Atogepant |
| Eptinezumab | Eptinezumab |
| Erenumab | Erenumab |
| Fremanezumab | Fremanezumab |
| Galcanezumab | Galcanezumab |
| Propranolol | OnabotulinumtoxinA |
| Topiramate | Topiramate |
| Valproate | Valproate |
CGRP-pathway therapies and atogepant are now central options, while traditional agents such as propranolol, topiramate, and valproate remain relevant in selected patients.
What if tolerability is the main concern?
If the patient is worried about side effects or has previously stopped treatment because of adverse effects, tolerability should guide the choice. The guideline highlights the following options when fewer side effects are a priority.
| Episodic migraine | Chronic migraine |
|---|---|
| Atogepant | Atogepant |
| Eptinezumab | Eptinezumab |
| Erenumab | Erenumab |
| Fremanezumab | Fremanezumab |
| Galcanezumab | Galcanezumab |
| — | OnabotulinumtoxinA |
This is clinically important because adherence often depends on whether the patient can tolerate the medication.
How do pregnancy and lactation affect treatment?
Pregnancy potential should be discussed before prescribing. Patients of childbearing potential must be counseled about possible fetal risks, and known teratogenic agents such as divalproex sodium and topiramate should be avoided if possible. In pregnancy or pregnancy planning, nonpharmacologic strategies should be maximized first.
If medication is necessary during pregnancy, the guideline mentions nifedipine, metoprolol, propranolol, and onabotulinumtoxinA for chronic migraine, but only after individualized risk-benefit discussion. During lactation, patients should be counseled that preventives may pass into breast milk in varying amounts.
How can comorbidities guide treatment?
Comorbidities can help personalize treatment. One medication may sometimes address both migraine and another condition, but response and adverse effects should be monitored.
| Clinical situation | Guideline-highlighted option |
|---|---|
| Untreated hypertension | Enalapril, nifedipine, telmisartan |
| Fibromyalgia | Amitriptyline |
| Increased BMI | Topiramate |
| Medication overuse | CGRP mAbs, atogepant, onabotulinumtoxinA, topiramate |
Medication overuse should not delay preventive therapy. The guideline recommends offering prevention to patients with medication overuse or medication-overuse headache.
When should response be assessed?
Preventive therapy should not be judged too early. Most medications should be assessed after 8–12 weeks at the recommended tolerated dose. For onabotulinumtoxinA, response should be assessed after 24 weeks.
| Treatment | Assess response after |
|---|---|
| Most migraine preventives | 8–12 weeks |
| OnabotulinumtoxinA | 24 weeks |
Treatment success should include migraine frequency, severity, associated symptoms, quality of life, acute medication use, and patient-defined goals.
When should treatment be stopped?
Stopping prevention should be deliberate, not automatic. After 6 months of treatment, clinicians should discuss the potential benefits and risks of tapering. Patients should know that limited evidence suggests stopping may increase headache days and reduce headache-related quality of life.
Key message
The 2026 AAN/AHS guideline supports a clearer approach to migraine prevention: offer treatment at ≥4 migraine days/month or substantial disability, choose medication around patient priorities and risks, and assess response only after an adequate trial.
Full reference
Potrebic S, Tanveer S, Becker WJ, Burch RC, Cooke LJ, Fenton T, Fletcher JJ, Gordon Perue GL, Hershey AD, Jackson JL, Kessel S, Loder EW, Minen MT, Oskoui M, Ramanan VK, Murren M, Schwedt TJ, Silberstein SD, Smith DB, Botchway-Doe KA, Silsbee HM, Pringsheim T. Pharmacologic Treatment for Migraine Prevention in Adults Practice Guideline Recommendations: Report of the AAN Guidelines Subcommittee and the American Headache Society. Neurology. 2026;107:e214881. doi:10.1212/WNL.0000000000214881.