CGRP inhibitors: how they work and what to expect

CGRP inhibitors are modern migraine medicines that block CGRP, a protein that plays a central role in migraine attacks. They are the first medicines developed specifically to prevent migraine, and for many people they mark a turning point. If you have already tried other medicines and your migraine continues, they may be an option for you.

What are CGRP inhibitors?

CGRP stands for calcitonin gene-related peptide. During a migraine attack more CGRP is released, which leads to irritation and inflammation of the pain nerves around the brain. CGRP inhibitors block this process and so tackle migraine at its source.

The difference from older preventive medicines is large. Classic preventives such as beta blockers, candesartan or topiramate were originally developed for other conditions (high blood pressure, epilepsy) and are used for migraine as well. CGRP inhibitors were designed for migraine from the start, so for the first time there is a treatment that acts directly on the migraine mechanism.

Which CGRP inhibitors are available?

Our migraine specialists can prescribe five CGRP medicines in two groups.

Monoclonal antibodies (injections)

• Erenumab: an injection under the skin every 4 weeks
• Fremanezumab: an injection under the skin every 4 weeks, or a larger dose every 3 months
• Galcanezumab: an injection under the skin every 4 weeks

You give these injections yourself at home with a pre-filled pen.

Gepants (tablets)

• Atogepant: a tablet taken every day to prevent attacks, or during an attack as acute treatment
• Rimegepant: a tablet that melts on the tongue, taken every other day to prevent attacks, or during an attack as acute treatment

Gepants are small molecules that block the CGRP receptor. We use atogepant and rimegepant for both acute treatment and prevention. Your migraine specialist decides with you which medicine suits your situation best.

How effective are CGRP inhibitors?

For many people the results are impressive. Many notice a clear improvement within a few months: fewer attacks, milder attacks and less impact on daily life. Many people who start them are still taking them a year later, a sign that they work and are well tolerated.

The chance of success is considerably higher than with classic preventive medicines, because CGRP inhibitors act directly on the migraine mechanism rather than indirectly through blood pressure or epilepsy medication.

What are the side effects of CGRP inhibitors?

Side effects are generally mild:

• Injection site reactions: redness, itching or swelling (with the injections)
• Constipation: in some people
• Tiredness: sometimes in the first weeks
• Nausea: mainly with the tablets

The first CGRP antibody was approved in 2018, and since then millions of people worldwide have used these medicines with no evidence of serious long-term side effects. It is sensible to keep an eye on your heart and blood vessel health, including your blood pressure, and your migraine specialist will discuss this with you.

Who can have CGRP inhibitors at The Migraine Clinic?

Our care is self-pay. You do not need to have tried and failed other preventive medicines or botox first. Your migraine specialist looks at your migraine, your medical history and your wishes, and together you decide whether a CGRP inhibitor is right for you. Our clinic is for adults aged 18 and over.

If you are taking painkillers or triptans very often, your migraine specialist will also talk to you about medication overuse headache, as this affects the plan.

About 10 million people in the UK live with migraine, and many wait years for specialist care. As a UK online migraine clinic, we guide you through the whole process, from your first video consultation to starting treatment. You pay for your medication in the App and our partner pharmacy delivers it to your door.

Frequently asked questions about CGRP inhibitors

What are CGRP inhibitors?

CGRP inhibitors are modern medicines developed specifically to prevent migraine attacks. They block the protein CGRP (calcitonin gene-related peptide), which plays a central role in how migraine attacks start.

How quickly do CGRP inhibitors work?

Many people notice an improvement within a few months. The full effect is usually assessed after three to six months of treatment.

Are CGRP inhibitors safe in the long term?

Since the first approval in 2018, millions of people have used them worldwide and no serious long-term side effects have been found. They are considered reliable and safe medicines.

How do I pay for CGRP inhibitors?

The Migraine Clinic UK is self-pay. You pay for your consultations and medication yourself, and your medication is paid in the App and delivered by our partner pharmacy. See our pricing page for details.

What is the difference between CGRP inhibitors and classic preventive medicines?

Classic preventive medicines were originally developed for other conditions and are also used for migraine. CGRP inhibitors were the first medicines developed specifically for migraine prevention, with a higher chance of success and fewer side effects.

Next steps

Want to know whether CGRP inhibitors could be right for you? Take our free migraine test, read more about preventive medication, or see how to start.

This article was written by the medical team of The Migraine Clinic.