What the label lists and what reports show
Fremanezumab side effects
Fremanezumab's FDA label: “The most common adverse reactions (≥5% and greater than placebo) were injection site reactions.” FAERS holds 11,413 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is accidental exposure to product (1,469 reports).
- No generic listed
Check it at the source: the fremanezumab FDA label on DailyMed (effective June 5, 2026); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of AJOVY?AJOVY may cause serious side effects, including: Allergic reactions. Allergic reactions, including itching, rash, and hives, can happen within hours and up to 1 month after receiving AJOVY. Call your healthcare provider or get emergency medical help right away if you have any of the following symptoms of an allergic reaction: swelling of your face, mouth, tongue, or throat trouble breathing Constipation with serious complications. Severe constipation can happen after receiving AJOVY. In some cases, people have been hospitalized or needed surgery. Contact your healthcare provider if you have severe constipation or constipation associated with symptoms such as severe or constant belly pain, vomiting, swelling of belly, or bloating. High blood pressure. High blood pressure or worsening of high blood pressure can happen after receiving AJOVY. […]
Source: FDA drug label, Teva Pharmaceuticals USA, Inc., effective June 5, 2026 (SPL set 98e344ea-5916-4947-b6f2-4a76ccc04b6b), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (≥5% and greater than placebo) were injection site reactions.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions are discussed in greater detail in other sections of the labeling: Hypersensitivity Reactions [see Warnings and Precautions ( 5.1 )] Constipation with Serious Complications [see Warnings and Precautions ( 5.2 )] Hypertension [see Warnings and Precautions ( 5.3 )] Raynaud’s Phenomenon [see Warnings and Precautions ( 5.4 )] The most common adverse reactions (≥5% and greater than placebo) were injection site reactions. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Teva Pharmaceuticals at 1-888-483-8279 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug, and may not reflect the rates observed in clinical practice. Adults The safety of AJOVY was evaluated in 2512 patients with migraine who received at least 1 dose of AJOVY, representing 1279 patient-years of exposure. Of these, 1730 patients were exposed to AJOVY 225 mg monthly or AJOVY 675 mg quarterly for at least 6 months, 775 patients for at least 12 months, and 138 patients for at least 15 months. …
Source: FDA drug label, Teva Pharmaceuticals USA, Inc., effective June 5, 2026 (SPL set 98e344ea-5916-4947-b6f2-4a76ccc04b6b), via openFDA; the full label on DailyMed
What do FAERS reports show?
11,413 reports list fremanezumab among the medicines taken, each a report of something that happened, not proof the medicine caused it; 108 are coded as a death and 829 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 19 reactions below, 5 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Fremanezumab: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions