If you've had migraines for years, you've probably been prescribed medications that weren't actually designed for migraine. Beta blockers borrowed from cardiology. Antidepressants prescribed off-label. Anti-seizure medications that worked for some patients and not others, often with significant side effects.
CGRP therapy is different. It's the first class of medications designed from the ground up specifically for migraine — and it's changed the treatment landscape more than anything in the past thirty years.
What CGRP actually is
CGRP stands for calcitonin gene-related peptide. It's a protein your body produces naturally, but in people with migraine, CGRP levels spike dramatically during attacks — and in chronic migraine patients, they're often elevated even between attacks.
Researchers figured out in the 1980s that CGRP was involved in migraine. It took another three decades to develop drugs that could block it. The first CGRP biologic, Aimovig, was approved by the FDA in 2018. Three more followed quickly: Ajovy, Emgality, and Vyepti.
These drugs work by either blocking CGRP itself or blocking the receptor it attaches to. The result: fewer migraine days, reduced attack severity, and for some patients, near-complete remission.
Who qualifies for CGRP therapy
CGRP biologics are FDA-approved for the preventive treatment of migraine in adults. In practice, they're typically prescribed for patients who:
- Have 4 or more migraine days per month
- Have tried and failed at least one or two traditional preventive medications (like topiramate, propranolol, or amitriptyline)
- Have not responded adequately to acute treatments alone
The "failed prior treatment" requirement matters because most commercial insurers require it before they'll cover CGRP biologics — which can cost $600–900 per month at list price. Prior authorization is the main reason patients who need these drugs don't get them. (It's also one of the main things Wellday handles for patients.)
If you haven't tried traditional preventives, that doesn't necessarily disqualify you — some patients go straight to CGRP with a strong clinical rationale. A clinician trained in migraine care makes that call based on your specific history.
How well do they work
Clinical trial data and real-world evidence are both strong. Across the four approved CGRP biologics, roughly 50–60% of patients see their migraine days cut in half or more. About 20-25% experience what researchers call a "75% responder" result — meaning their migraine days drop by three quarters. A smaller but meaningful percentage achieves near-complete remission.
These numbers are substantially better than older preventives, which have response rates closer to 30-40% and often come with side effects (weight gain, cognitive fog, fatigue) that cause patients to discontinue.
CGRP biologics are also generally well-tolerated. The most common side effect is injection site reactions. Some patients report constipation. Serious adverse events are rare.
The four CGRP biologics — what's different between them
All four work through the CGRP pathway, but they differ in administration and targeting:
Aimovig (erenumab) — Monthly subcutaneous injection. Blocks the CGRP receptor rather than CGRP itself.
Ajovy (fremanezumab) — Monthly or quarterly subcutaneous injection. Blocks CGRP directly.
Emgality (galcanezumab) — Monthly subcutaneous injection. Blocks CGRP directly. Also FDA-approved for cluster headache.
Vyepti (eptinezumab) — Quarterly intravenous infusion administered in a clinical setting. Only IV option; reaches full effect faster than the injectables.
The right choice depends on your preference for injection frequency, whether you prefer self-injection or infusion, insurance coverage, and your clinician's recommendation.
What about oral CGRP medications
There's a second class of CGRP medications — oral pills taken acutely (during attacks) rather than preventively.
Ubrelvy (ubrogepant) and Nurtec (rimegepant) are gepants — oral CGRP receptor antagonists designed to stop a migraine attack once it starts. Nurtec is also approved for prevention when taken every other day.
Qulipta (atogepant) is an oral preventive CGRP medication taken daily.
These are particularly useful for patients who can't tolerate triptans, or as add-ons to biologic therapy.
How to get started
If you're a migraine patient with frequent attacks and haven't tried CGRP therapy, the path forward is a consultation with a clinician trained in migraine care. They'll review your history, discuss whether CGRP is appropriate for you, and handle the prior authorization process if insurance is involved.
That last part — prior authorization — is where most patients get stuck. It requires documentation, specific diagnostic codes, evidence of prior treatment failures, and often multiple rounds of appeals. Most primary care providers don't have the bandwidth to fight it. The roughly 564 board-certified headache specialists in the country do, but the waitlists are often 6-8 months.
Wellday was built to close that gap. If you'd like to find out whether you're a candidate for CGRP therapy, build your free migraine profile — it takes about five minutes, and we'll let you know where you stand before any payment.