Drug · FAERS side-effect profile with label screen
Fremanezumab-Vfrm side effects: what 11,410 FDA adverse event reports show
Drug class
Calcitonin gene-related peptide antagonist
FDA label, Indications wording
Brand names
Ajovy
openFDA label
Who reports
11,410 reports · 33% serious · 108 with death outcome · 89% female
openFDA FAERS counts, all years, deduplication not applied
Used for
AJOVY is indicated for: the preventive treatment of migraine in adults, and the preventive treatment of episodic migraine in pediatric patients who are 6 to 17 years of age and who weigh 45 kg or more. AJOVY is a calcitonin gene-related peptide antagon.
FDA label, Indications and Usage
What it is
Fremanezumab-vfrm is a humanized IgG2Δa/kappa monoclonal antibody specific for calcitonin gene-related peptide (CGRP) ligand. Fremanezumab-vfrm is produced by recombinant DNA technology in Chinese hamster ovary (CHO) cells. The antibody consists of 1324 amino acids and has a molecular weight of approximately 148 kDa.
FDA label, Description section
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Labeled (related wording) 19Likely indication confounding 4Reporting / coding artifact 9Not in label — unassessed 8
What the badges mean
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 954 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Device audio issue | 45 | 1,382.1 938.1–2,036.2ROR 1,387.6 · χ² 34,453 / p <1e-300 | 587.4 EB05 456.9 · IC025 +5.9 3/3 methods agree | Reporting / coding artifact | serious n=3 · 98% consumer | no trial data cached |
| Status migrainosus | 10 | 129.4 68.2–245.8ROR 129.5 · χ² 1,073 / p 2e-235 | 98.7 EB05 57.3 · IC025 +3.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=7 | no trial data cached |
| Hemiplegic migraine | 13 | 75.3 43.2–131.0ROR 75.3 · χ² 845 / p 5e-186 | 65.6 EB05 40.8 · IC025 +3.4 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=9 | no trial data cached |
| Injection site discharge | 126 | 46.5 39.0–55.5ROR 47.1 · χ² 5,432 / p <1e-300 | 45.1 EB05 38.9 · IC025 +5.0 3/3 methods agree | Labeled (related wording) related wording | serious n=4 · 90% consumer | no trial data cached |
| Medication overuse headache | 15 | 32.8 19.7–54.6ROR 32.8 · χ² 423 / p 2e-94 | 31.1 EB05 20.0 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Incorrect dose administered by device | 396 | 29.1 26.4–32.1ROR 30.1 · χ² 10,557 / p <1e-300 | 28.6 EB05 26.3 · IC025 +4.6 3/3 methods agree | Reporting / coding artifact | serious n=24 · 89% consumer | no trial data cached |
| Accidental exposure to product | 1,469 | 27.4 26.1–28.8ROR 31.3 · χ² 36,973 / p <1e-300 | 27.0 EB05 25.9 · IC025 +4.7 3/3 methods agree | Reporting / coding artifact | serious PRR 15.6 · 89% consumer | no trial data cached |
| Immediate post-injection reaction | 16 | 27.0 16.5–44.2ROR 27.0 · χ² 369 / p 1e-82 | 25.9 EB05 16.8 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=9 | no trial data cached |
| Injection site extravasation | 167 | 24.9 21.4–29.0ROR 25.3 · χ² 3,759 / p <1e-300 | 24.5 EB05 21.6 · IC025 +4.3 3/3 methods agree | Labeled (related wording) related wording | 90% consumer | no trial data cached |
| Device leakage | 565 | 24.8 22.9–26.9ROR 26.1 · χ² 12,756 / p <1e-300 | 24.5 EB05 22.9 · IC025 +4.4 3/3 methods agree | Reporting / coding artifact | serious n=29 · 89% consumer | no trial data cached |
| Device alarm issue | 24 | 24.8 16.6–37.0ROR 24.8 · χ² 517 / p 1e-114 | 24.0 EB05 17.0 · IC025 +3.4 3/3 methods agree | Reporting / coding artifact | 100% consumer | no trial data cached |
| Injection related reaction | 20 | 23.1 14.9–35.9ROR 23.2 · χ² 396 / p 2e-88 | 22.4 EB05 15.2 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Injection site oedema | 20 | 21.8 14.0–33.8ROR 21.8 · χ² 372 / p 4e-83 | 21.1 EB05 14.3 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious n=15 | no trial data cached |
| Migraine | 1,048 | 20.5 19.4–21.7ROR 22.5 · χ² 19,303 / p <1e-300 | 20.3 EB05 19.3 · IC025 +4.2 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 23.9 · 82% consumer | no trial data cached |
| Injection site hypersensitivity | 33 | 19.9 14.1–28.1ROR 20.0 · χ² 568 / p 7e-126 | 19.5 EB05 14.5 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious n=11 · 76% consumer | no trial data cached |
| Abortion missed | 13 | 18.9 11.0–32.7ROR 19.0 · χ² 201 / p 6e-46 | 17.9 EB05 10.6 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Device delivery system issue | 255 | 18.1 16.0–20.4ROR 18.5 · χ² 4,066 / p <1e-300 | 17.9 EB05 16.1 · IC025 +3.9 3/3 methods agree | Reporting / coding artifact | serious n=16 · 93% consumer | no trial data cached |
| Needle issue | 279 | 18.1 16.1–20.3ROR 18.5 · χ² 4,449 / p <1e-300 | 17.9 EB05 16.2 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=18 · 87% consumer | no trial data cached |
| Injection site rash | 279 | 17.0 15.2–19.1ROR 17.4 · χ² 4,163 / p <1e-300 | 16.9 EB05 15.3 · IC025 +3.8 3/3 methods agree | Labeled (related wording) related wording | serious n=66 | no trial data cached |
| Drug delivery system issue | 17 | 16.7 10.4–27.0ROR 16.8 · χ² 234 / p 4e-53 | 16.0 EB05 10.1 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Injection site scar | 25 | 16.4 11.1–24.4ROR 16.5 · χ² 344 / p 4e-77 | 16.0 EB05 11.1 · IC025 +3.0 3/3 methods agree | Labeled (related wording) related wording | serious n=4 · 92% consumer | no trial data cached |
| Injection site cellulitis | 15 | 15.1 9.1–25.1ROR 15.1 · χ² 182 / p 9e-42 | 14.1 EB05 8.4 · IC025 +2.5 3/3 methods agree | Labeled (related wording) related wording | serious n=12 | no trial data cached |
| Device defective | 130 | 14.9 12.5–17.7ROR 15.0 · χ² 1,656 / p <1e-300 | 14.7 EB05 12.7 · IC025 +3.5 3/3 methods agree | Reporting / coding artifact | serious n=11 · 88% consumer | no trial data cached |
| Injection site pruritus | 500 | 13.9 12.8–15.2ROR 14.5 · χ² 5,947 / p <1e-300 | 13.8 EB05 12.8 · IC025 +3.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 37.9 · 72% consumer | no trial data cached |
| Injection site urticaria | 178 | 13.6 11.7–15.7ROR 13.8 · χ² 2,048 / p <1e-300 | 13.4 EB05 11.8 · IC025 +3.5 3/3 methods agree | Labeled (related wording) related wording | serious n=24 · 74% consumer | no trial data cached |
| Device malfunction | 493 | 13.6 12.4–14.8ROR 14.1 · χ² 5,705 / p <1e-300 | 13.5 EB05 12.5 · IC025 +3.6 3/3 methods agree | Reporting / coding artifact | serious PRR 6.8 · 88% consumer | no trial data cached |
| Injection site warmth | 133 | 11.9 10.1–14.1ROR 12.1 · χ² 1,314 / p 5e-288 | 11.8 EB05 10.2 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious n=38 · 76% consumer | no trial data cached |
| Patient dissatisfaction with treatment | 12 | 11.7 6.6–20.6ROR 11.7 · χ² 106 / p 3e-25 | 10.0 EB05 5.5 · IC025 +2.1 3/3 methods agree | Labeled (related wording) related wording | – | no trial data cached |
| Therapeutic product effect variable | 24 | 11.6 7.8–17.3ROR 11.6 · χ² 221 / p 3e-50 | 10.8 EB05 7.3 · IC025 +2.6 3/3 methods agree | Reporting / coding artifact | serious n=3 · 79% consumer | no trial data cached |
| Injection site inflammation | 31 | 11.6 8.1–16.5ROR 11.6 · χ² 288 / p 8e-65 | 11.0 EB05 7.8 · IC025 +2.7 3/3 methods agree | Labeled (related wording) related wording | serious n=9 · 90% consumer | no trial data cached |
| Injection site vesicles | 37 | 11.4 8.2–15.7ROR 11.4 · χ² 338 / p 8e-76 | 10.9 EB05 8.0 · IC025 +2.8 3/3 methods agree | Labeled (related wording) related wording | serious n=9 | no trial data cached |
| Injection site mass | 224 | 11.2 9.9–12.8ROR 11.4 · χ² 2,067 / p <1e-300 | 11.1 EB05 9.9 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 15.8 · 83% consumer | no trial data cached |
| Injection site swelling | 447 | 10.9 9.9–11.9ROR 11.3 · χ² 3,999 / p <1e-300 | 10.8 EB05 10.0 · IC025 +3.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 24.7 · 72% consumer | no trial data cached |
| Migraine with aura | 16 | 10.9 6.7–17.8ROR 10.9 · χ² 133 / p 4e-31 | 9.6 EB05 5.8 · IC025 +2.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=9 | no trial data cached |
| Injection site indentation | 12 | 10.9 6.2–19.2ROR 10.9 · χ² 97 / p 3e-23 | 9.1 EB05 5.1 · IC025 +2.0 3/3 methods agree | Labeled (related wording) related wording | – | no trial data cached |
| Injection site induration | 76 | 10.8 8.7–13.6ROR 10.9 · χ² 665 / p 7e-147 | 10.6 EB05 8.6 · IC025 +3.0 3/3 methods agree | Labeled (related wording) related wording | serious n=16 · 75% consumer | no trial data cached |
| Emergency care | 17 | 10.6 6.6–17.0ROR 10.6 · χ² 137 / p 6e-32 | 9.3 EB05 5.8 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious n=7 | no trial data cached |
| Drug dose omission by device | 432 | 10.4 9.5–11.4ROR 10.8 · χ² 3,660 / p <1e-300 | 10.3 EB05 9.5 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=32 · 89% consumer | no trial data cached |
| Injection site erythema (redness where injected) | 663 | 9.9 9.2–10.7ROR 10.5 · χ² 5,309 / p <1e-300 | 9.8 EB05 9.2 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 22.3 · 70% consumer | no trial data cached |
| Injection site discolouration | 64 | 9.5 7.5–12.2ROR 9.6 · χ² 478 / p 3e-106 | 9.2 EB05 7.4 · IC025 +2.7 3/3 methods agree | Labeled (related wording) related wording | serious n=14 · 81% consumer | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Accidental exposure to product | 1,469 | 27.4 26.1–28.8ROR 31.3 · χ² 36,973 / p <1e-300 | 27.0 EB05 25.9 · IC025 +4.7 3/3 methods agree | Reporting / coding artifact | serious PRR 15.6 · 89% consumer | no trial data cached |
| Injection site pain (pain where injected) | 1,318 | 8.0 7.6–8.4ROR 8.9 · χ² 8,160 / p <1e-300 | 8.0 EB05 7.6 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.5 · 87% consumer | no trial data cached |
| Migraine | 1,048 | 20.5 19.4–21.7ROR 22.5 · χ² 19,303 / p <1e-300 | 20.3 EB05 19.3 · IC025 +4.2 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 23.9 · 82% consumer | no trial data cached |
| Drug ineffective (drug did not work) | 920 | 1.3 1.2–1.4ROR 1.3 · χ² 61 / p 2e-15 | 1.3 EB05 1.2 · IC025 +0.3 | Reporting / coding artifact | serious PRR 1.1 · 78% consumer | no trial data cached |
| Headache | 742 | 2.2 2.0–2.3ROR 2.3 · χ² 486 / p 5e-108 | 2.2 EB05 2.0 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 2.8 · 75% consumer | no trial data cached |
| Injection site erythema (redness where injected) | 663 | 9.9 9.2–10.7ROR 10.5 · χ² 5,309 / p <1e-300 | 9.8 EB05 9.2 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 22.3 · 70% consumer | no trial data cached |
| Device leakage | 565 | 24.8 22.9–26.9ROR 26.1 · χ² 12,756 / p <1e-300 | 24.5 EB05 22.9 · IC025 +4.4 3/3 methods agree | Reporting / coding artifact | serious n=29 · 89% consumer | no trial data cached |
| Injection site pruritus | 500 | 13.9 12.8–15.2ROR 14.5 · χ² 5,947 / p <1e-300 | 13.8 EB05 12.8 · IC025 +3.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 37.9 · 72% consumer | no trial data cached |
| Fatigue (tiredness) | 498 | 1.2 1.1–1.3ROR 1.2 · χ² 14 / p 1e-4 | 1.2 EB05 1.1 · IC025 +0.1 | Not in label — unassessed | serious PRR 2.3 · 75% consumer | no trial data cached |
| Device malfunction | 493 | 13.6 12.4–14.8ROR 14.1 · χ² 5,705 / p <1e-300 | 13.5 EB05 12.5 · IC025 +3.6 3/3 methods agree | Reporting / coding artifact | serious PRR 6.8 · 88% consumer | no trial data cached |
| Nausea | 492 | 1.1 1.1–1.2ROR 1.2 · χ² 9 / p 0.001 | 1.1 EB05 1.1 · IC025 +0.0 | Not in label — unassessed | serious PRR 2.0 · 77% consumer | no trial data cached |
| Injection site swelling | 447 | 10.9 9.9–11.9ROR 11.3 · χ² 3,999 / p <1e-300 | 10.8 EB05 10.0 · IC025 +3.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 24.7 · 72% consumer | no trial data cached |
| Drug dose omission by device | 432 | 10.4 9.5–11.4ROR 10.8 · χ² 3,660 / p <1e-300 | 10.3 EB05 9.5 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=32 · 89% consumer | no trial data cached |
| Dizziness | 396 | 1.5 1.3–1.6ROR 1.5 · χ² 59 / p 9e-15 | 1.5 EB05 1.3 · IC025 +0.4 | Not in label — unassessed | serious PRR 2.8 · 75% consumer | no trial data cached |
| Incorrect dose administered by device | 396 | 29.1 26.4–32.1ROR 30.1 · χ² 10,557 / p <1e-300 | 28.6 EB05 26.3 · IC025 +4.6 3/3 methods agree | Reporting / coding artifact | serious n=24 · 89% consumer | no trial data cached |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Injection related reaction — n=20, PRR 23.1
- Needle issue — n=279, PRR 18.1
- Drug dose omission by device — n=432, PRR 10.4
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Fremanezumab-Vfrm?
In FDA FAERS, the most frequently co-reported reaction terms for Fremanezumab-Vfrm are injection site pain, migraine, headache, injection site erythema, injection site pruritus, fatigue. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Fremanezumab-Vfrm have an FDA boxed warning?
No. The FDA label retrieved for Fremanezumab-Vfrm has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Fremanezumab-Vfrm causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 98e344ea-5916-4947-b6f2-4a76ccc04b6b, effective 20260605; matched on
openfda.generic_name.exact:"FREMANEZUMAB-VFRM") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 994 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath
Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.