fremanezumab
Ajovy (fremanezumab) is a monoclonal antibody from Teva that binds calcitonin gene-related peptide (CGRP), a key molecule in migraine biology. Given monthly or quarterly by injection, it prevents migraine attacks in adults and selected adolescents.
This page is based on FDA prescribing information and the EMA medicine record for fremanezumab, cross-checked with DailyMed; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
A migraine is like a fire alarm circuit that keeps tripping, and CGRP is the spark that keeps jumping across the gap. Fremanezumab is a blanket laid over the gap: the sparks still occur, but they cannot jump, so the alarm stays quiet and fewer migraine days are triggered.
In simple terms
During migraine, pain nerves around the brain release CGRP, which widens blood vessels and passes pain signals onward. Fremanezumab is an antibody that binds CGRP itself, stopping it from reaching its receptors. With the signal blocked, migraine attacks become less frequent and less severe. It is injected under the skin once a month, or as three injections every three months.
In depth
Fremanezumab is a humanised IgG2-delta monoclonal antibody that binds CGRP ligand with picomolar affinity, preventing activation of the CGRP receptor without targeting the receptor itself. Its long half-life of about one month supports monthly or quarterly subcutaneous dosing. By neutralising CGRP it suppresses trigeminovascular nociceptive transmission and meningeal vasodilation, reducing monthly migraine days in both episodic and chronic migraine.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
How fremanezumab neutralises the CGRP ligand to prevent migraine
- A migraine is like a fire alarm circuit that keeps tripping, and CGRP is the spark that keeps jumping across the gap.
- Fremanezumab is a humanised IgG2-delta monoclonal antibody that binds CGRP ligand with picomolar affinity, preventing activation of the CGRP receptor without targeting the receptor itself.
- Its long half-life of about one month supports monthly or quarterly subcutaneous dosing.
- By neutralising CGRP it suppresses trigeminovascular nociceptive transmission and meningeal vasodilation, reducing monthly migraine days in both episodic and chronic migraine.
Target: Calcitonin gene-related peptide (CGRP)
A neuropeptide released around pain-sensing nerves of the trigeminal system during migraine; it dilates meningeal vessels and amplifies pain signalling, so neutralising it reduces attack frequency.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in United States
FDA- Preventive treatment of migraine in adults
- Preventive treatment of episodic migraine in pediatric patients 6 to 17 years of age who weigh 45 kg or more
Approved uses in European Union
EMA- Prophylaxis of migraine in adults who have at least 4 migraine days per month
Official sources
The statements on this page trace back to these records.
- Ajovy (fremanezumab) — Summary of product characteristics and package leaflet, English version
European Medicines Agency
- DailyMed: Ajovy (fremanezumab) label
DailyMed, U.S. National Library of Medicine
- U.S. Food and Drug Administration: fremanezumab prescribing information
U.S. Food and Drug Administration
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.