CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-24). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 1862 · Search date 2026-07-24 · Methodology v0.6

Propranolol,
does it really help with Reduction in attack frequency for adult episodic migraine prevention?

30-Second Summary
C
Evidence Grade C · 56 · Safety caution
Migraine prevention is repeatedly supported, although reporting limitations remain in older small trials
Bradycardia, hypotension, fatigue, dizziness, and sleep disturbance can occur. Asthma, severe peripheral circulatory disease, and some conduction disorders may preclude use, and abrupt withdrawal should be avoided.
What the
research shows
Propranolol is rated C. Older placebo-controlled trials repeatedly improved migraine frequency and response, but the index trial randomized only 96 people and based efficacy mainly on 80 completers.
What the
ads claim
Prevention can be marketed as elimination of attacks, but average response varies and should be assessed over weeks at a tolerated dose.
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Useful facts when choosing a product

  • The index crossover trial used propranolol 80 mg twice daily.
  • The distinct counts are 96 randomized, 80 in the efficacy analysis, and 83 in adverse-event data.
Gap Measurement · Verdict 1862 · C 56
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Tfelt-Hansen 1984 enrolled 96 people in a three-period crossover trial. Eighty-three received all three treatments and contributed adverse-event data, while the Cochrane efficacy extraction used 80. Propranolol produced 3.69 attacks per 28 days and a headache index of 6.66 versus 4.83 and 9.03 with placebo. The 2004 Cochrane review included 58 trials and 5,072 participants, including 26 placebo-controlled trials. Across nine trials with response data, the risk ratio for at least 50% response was 1.94 (95% CI 1.61 to 2.35). International Headache Society prevention-trial guidance identifies at least 50% reduction as a clinically relevant response threshold; it is used only to source the threshold, not to recommend treatment. Funding was unreported for many of the 26 placebo-controlled trials, and independent review does not change source-trial funding.

02

Why this is classified as C (56)

Replicated patient-important response is tempered by a 96-person index trial, an efficacy analysis centered on 80 completers, and incomplete source-trial funding reports, yielding C with 56 points.

Counterpoint. Asthma, bradycardia, low blood pressure, comedications, and gradual dose adjustment matter in selection.

Rejudgment record. Cross-check applied — Accepted replicated placebo-controlled prevention effects while accounting for a 96-person trial and efficacy analysis centered on 80 completers

Scoring profile behind this grade
EndpointPPatient-reported treatment goal - the symptom is the goal
ReplicationR2Independently replicated across trials
IndependenceI1Mixed funding sources
Effect sizeE+Meets the clinically important threshold

The scoring table and the verdict agree (C).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Reduction in monthly migraine attack frequencyBMultiple placebo-controlled trials consistently found a reduction.
At least 50% reduction in attack frequencyBThe pooled risk ratio across nine trials was 1.94.
Reduction in headache indexBThe index trial found 6.66 versus 9.03, P<0.01.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Tfelt-Hansen P et al. 1984Four-center randomized double-blind three-period crossover placebo- and active-controlled trial83Funding source not identified in the accessible abstract or bibliographic recordMigraine attack frequency per 28 days and headache index3.69 versus 4.83 attacks, P<0.05, and headache index 6.66 versus 9.03, P<0.01; primary clinical comparison succeededDirect placebo-controlled efficacy evidence
Linde K, Rossnagel K. 2004Cochrane systematic review and meta-analysis of randomized trials26No separate industry funding reported for the review; funding was inadequately reported in many included trialsAttack frequency and at least 50% responseRisk ratio 1.94 (95% CI 1.61 to 2.35) across nine trials with response data; multiple trials positiveReplication across multiple research groups
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-07-24).

Tfelt-Hansen P, Standnes B, Kangasniemi P, Hakkarainen H, Olesen J. Timolol vs propranolol vs placebo in common migraine prophylaxis: a double-blind multicenter trial. Acta Neurol Scand. 1984;69(1):1-8. PMID: 6367336. DOI: 10.1111/j.1600-0404.1984.tb07772.x.
checked
Linde K, Rossnagel K. Propranolol for migraine prophylaxis. Cochrane Database Syst Rev. 2004;2004(2):CD003225. PMID: 15106196. DOI: 10.1002/14651858.CD003225.pub2.
checked
Tfelt-Hansen P, Pascual J, Ramadan N, et al. Guidelines for controlled trials of drugs in migraine: third edition. A guide for investigators. Cephalalgia. 2012;32(1):6-38. PMID: 22384463. DOI: 10.1177/0333102411417901.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-24 · Corrections: none

Cite this verdict

Propranolol x migraine attack prevention Evidence Grade C card
[Chamgap] Propranolol x migraine attack prevention — Evidence Grade C·56. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/cognition/propranolol-episodic-migraine-prevention/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.