CGRP Inhibitors for Migraine

Medically Reviewed by Murtaza Cassoobhoy, MD on February 09, 2023
4 min read

Migraine is a pain.

While several over-the-counter and prescription medications can treat migraine, not all are good at easing symptoms like head pain, nausea, vomiting, and sensitivity to light that can last a few hours or a few days.

For the 36 million Americans who have migraine, treating the symptoms is one part of the battle: Another critical goal is preventing the painful headaches, and there hasn’t been a medication for that. Until now.

In 2018, the FDA approved the first calcitonin gene-related peptide (CGRP) inhibitors. These new drugs are designed to prevent episodic migraine (up to 14 headache days per month), chronic migraine (15 headache days per month or more), and medication overuse headaches. CGRP inhibitors were the first class of drugs developed to prevent migraines with or without visual auras. Experts recommend their use for those with 6 or more migraine days per month, or when older preventive migraine treatments fail or are not tolerated by the migraine sufferer.

In 2021 a subset of CGRP inhibitors were approved to treat acute migraine.

The American Migraine Foundation calls CGRP inhibitors, “the biggest news in migraine treatment and prevention in decades.”

CGRP is the acronym for calcitonin gene-related peptide. It’s involved in a lot of body processes: It regulates blood pressure, helps with tissue repair and wound healing, and contributes to inflammation.

When CGRP is released in the brain, it affects the trigeminal nerve, which is responsible for communicating pain and sensitivities to touch and temperature. CGRP also causes inflammation and pain that happens during a migraine; it makes headache pain worse and causes headaches to last longer. It appears that those who are diagnosed with migraine have more CGRP in their blood.

CGRP inhibitors are drugs that block CGRP from binding to CGRP receptors, a key contributor to the trigeminal nerve pain and inflammation of migraine. Some are FDA-approved for preventing migraine, others for treating acute migraine, and one is approved for both acute and preventive therapy. 

The two classes of these drugs are monoclonal antibodies and small molecule CGRP antagonists. The CGRP monoclonal antibodies are large molecule drugs that are given as self-injections or IVs. The shots are given with an automatic pen (similar to the injection pens used for insulin) every month or quarterly (four times per year), depending on the drug. The small molecule CGRP antagonists are taken by mouth in pill form.

Preventive migraine treatment:

  • Given by injection or IV 
    • Erenumab (Aimovig)
    • Eptinezumab (Vyepti)
    • Fremanezumab (Ajovy)
    • Galcanezumab (Emgality)
  • Oral
    • Atogepant (Qulipta) 
    • Rimegepant (Nurtec)
  • Nasal
    • Zavegepant (Zavzpret)

Acute migraine treatment:

  • Oral 
    • Rimegepant (Nurtec)
    • Ubrogepant (Ubrelvy)
  • Nasal
    • Zavegepant (Zavzpret)

CGRP migraine medications can also be called anti-CGRP, CGRP inhibitors, CGRP antagonist treatments, and CGRP monoclonal  antibodies for migraine.

Studies show that CGRP inhibitors helped make migraines come less often, lessened headache days, and cut medication usage among those who had episodic and chronic migraine with or without aura.

You’ll need a prescription from your doctor for CGRP inhibitors.

CGRP inhibitors have been shown to work better than conventional migraine medications, which research shows might not be good at relieving migraine pain and often come with side effects, including medication overuse headaches. CGRP inhibitors also appear to work faster than other acute migraine treatments.

It often takes up to 3 months to figure out whether traditional migraine medications are working, but most people who take CGRP inhibitors to prevent or treat migraine see results in the first month.

CGRP inhibitors tend to be well-tolerated. In fact, one study found that those with episodic migraine had no more reaction to the CGRP inhibitor than a placebo (sugar pill), and just 6% of those who gave themselves injections had reactions where they got the shot.

Some mild to moderate side effects from CGRP inhibitors have been reported, including:

  • Nausea
  • Vomiting
  • Back pain
  • Headache
  • Visual problems
  • Tingling or “pins and needles” sensations
  • Dry mouth
  • Upper respiratory infections
  • Urinary tract infections
  • Fatigue
  • Joint stiffness
  • Liver toxicity
  • Pain where you get the shot (for CGRP inhibitors given via injection or IV)


CGRP inhibitors work on episodic and chronic migraines.

Data shows the drugs have a strong safety profile. In fact, the latest research found there were no adverse reactions. But researchers noted that the drugs are new and there still isn’t a lot of long-term data, so it’s important to talk to your doctor.

At first, there were some concerns about prescribing CGRP inhibitors to those with heart disease. CGRP is called a vasodilator because it helps the blood vessels dilate, which is important for good heart health; the peptide has also been shown to protect against heart failure and high blood pressure. The results from several clinical trials showed there doesn’t appear to be an increased risk.

For those with episodic migraine, data shows that almost 88% of people studied had fewer headache days. The same study found that CGRP inhibitors significantly reduced the number of headache days for 84% of those with chronic migraine.

Other research has shown that CGRP inhibitors are better at relieving migraine pain than conventional migraine medications. In one study where more than half of participants had previously tried at least two preventive migraine medications, 30% reported that CGRP inhibitors significantly reduced how often they had migraines.

CGRP inhibitors may be especially effective if you have a lot of side effects or don’t get headache relief from conventional migraine medications. Talk to your doctor about whether CGRP inhibitors might be the right medication to treat or prevent migraine.