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approvedImmune & Inflammation

CGRP

Also known as: Calcitonin Gene-Related Peptide, α-CGRP, CGRP-alpha

Calcitonin Gene-Related Peptide (CGRP) is a 37-amino-acid neuropeptide and one of the most potent vasodilators known. It is the primary mediator of migraine pathophysiology — released from trigeminal nerve fibers during migraine attacks, it causes meningeal vasodilation, neurogenic inflammation, and pain sensitization. This discovery revolutionized migraine treatment, producing an entire drug class: anti-CGRP monoclonal antibodies (erenumab, fremanezumab, galcanezumab, eptinezumab) and CGRP receptor antagonists (gepants) are now first-line migraine preventives.

4 cited references·5 researched benefits

Quick Answer

CGRP (Calcitonin Gene-Related Peptide) is a 37-amino-acid vasodilatory neuropeptide that is the central mediator of migraine attacks. Released from trigeminal nerve fibers, it causes meningeal vasodilation and pain sensitization. This discovery produced a revolutionary drug class: anti-CGRP antibodies (erenumab, fremanezumab, galcanezumab) and CGRP receptor antagonists (gepants like rimegepant and ubrogepant) are now first-line migraine preventives, representing the first mechanism-specific migraine therapies.

Key Facts

Mechanism
CGRP is generated by alternative splicing of the calcitonin gene (CALCA) in sensory neurons. It binds a heterodimeric receptor complex: calcitonin receptor-like receptor (CLR) paired with receptor activity-modifying protein 1 (RAMP1). This Gs-coupled receptor activates adenylyl cyclase, increasing cAMP and protein kinase A activity. In the trigeminovascular system, CGRP release from trigeminal ganglion neurons dilates meningeal blood vessels, activates mast cells (releasing histamine and other inflammatory mediators), and sensitizes trigeminal nociceptors. Centrally, CGRP signaling in the trigeminal nucleus caudalis amplifies pain processing. The cycle of CGRP release → vasodilation → neurogenic inflammation → pain sensitization → further CGRP release drives the sustained headache phase of migraine.
Research Status
approved
Half-Life
~6.9 minutes (plasma)
Molecular Formula
C₁₈₆H₂₉₁N₅₅O₅₆S₃
Primary Use
Immune & Inflammation
Table of Contents

Benefits

  • Migraine drug target — anti-CGRP therapies prevent 3–8 monthly migraine days, transforming treatment for episodic and chronic migrainestrong
  • Vasodilation — CGRP is the most potent vasodilator known, important for cardiovascular and wound healing researchstrong
  • Neuroprotection — CGRP may protect against ischemic neuronal damage through increased cerebral blood flowmoderate
  • Wound healing — promotes angiogenesis and fibroblast proliferation in skin woundsmoderate
  • Cardioprotection — CGRP reduces myocardial ischemia-reperfusion injury in preclinical modelspreliminary

Dosage Protocols

RouteDosage RangeFrequencyNotes
Not administered therapeutically (endogenous peptide)N/AN/ACGRP itself is not used therapeutically. Anti-CGRP therapies include: monoclonal antibodies (erenumab 70–140 mg monthly SC, fremanezumab 225 mg monthly SC, galcanezumab 120 mg monthly SC, eptinezumab 100–300 mg quarterly IV) and gepants (rimegepant 75 mg as needed or daily, ubrogepant 50–100 mg acute).

Medical disclaimer

Dosage information is provided for educational reference only. Always follow your prescriber's instructions and consult a qualified healthcare provider before starting any peptide protocol.

Side Effects

  • CGRP blockade: constipation — anti-CGRP antibodies cause constipation in 3–5% of patients due to reduced GI CGRP signalingcommon
  • CGRP blockade: injection-site reactions — anti-CGRP antibody injections cause pain, erythema, or pruritus at injection sitecommon
  • Exogenous CGRP: hypotension — CGRP infusion causes significant blood pressure reduction due to potent vasodilationserious
  • Exogenous CGRP: migraine provocation — IV CGRP reliably triggers migraine attacks in susceptible individuals (used in research)serious
  • CGRP blockade: theoretical cardiovascular risk — long-term CGRP inhibition could theoretically impair cardioprotective vasodilation, though not observed clinicallyrare

Frequently Asked Questions

How did CGRP transform migraine treatment?
Before anti-CGRP therapies, migraine preventives were borrowed from other conditions: beta-blockers (hypertension), topiramate (epilepsy), amitriptyline (depression), botulinum toxin. These had limited efficacy (30–50% responder rates) and significant side effects. Anti-CGRP monoclonal antibodies, introduced starting in 2018, are the first mechanism-specific migraine preventives with 50–60% responder rates, minimal side effects, and convenient monthly or quarterly dosing. Gepants (small molecule CGRP receptor antagonists) added oral acute and preventive options.
What is the difference between anti-CGRP antibodies and gepants?
Anti-CGRP monoclonal antibodies (erenumab targets the receptor; fremanezumab, galcanezumab, and eptinezumab target the CGRP ligand) are large proteins given by injection or infusion monthly/quarterly for prevention only. Gepants (rimegepant, ubrogepant, atogepant, zavegepant) are small molecule CGRP receptor antagonists taken orally for both acute treatment and prevention. Gepants have shorter duration of action (hours vs weeks) and can be used situationally. Some patients use both: an antibody for baseline prevention plus a gepant for breakthrough attacks.
Does blocking CGRP long-term have cardiovascular risks?
CGRP is cardioprotective — it vasodilates coronary arteries and may protect against ischemia. Theoretically, chronic CGRP blockade could impair these protective effects. However, 5+ years of clinical experience with anti-CGRP antibodies in millions of patients has not revealed increased cardiovascular events. This may be because: (1) antibodies have limited blood-brain barrier penetration, primarily blocking peripheral CGRP; (2) compensatory vasodilatory mechanisms (nitric oxide, prostaglandins) maintain vascular function; (3) patients with significant cardiovascular disease were excluded from initial trials.
Why does CGRP cause migraine in susceptible people but not everyone?
When CGRP is infused intravenously into migraine patients, it reliably triggers migraine attacks within hours. In non-migraineurs, the same dose causes only mild headache or no headache. This suggests that migraine brains have a heightened sensitivity to CGRP — possibly due to lower CGRP degradation rates, increased CGRP receptor expression, or lower thresholds for trigeminovascular activation. This "CGRP hypersensitivity" may be genetically determined and is a key feature of the migraine phenotype.
Is CGRP involved in conditions other than migraine?
Yes. CGRP is implicated in: cluster headache (elevated CGRP during attacks; galcanezumab is FDA-approved for prevention), Raynaud's phenomenon (reduced CGRP may contribute to vasospasm), complex regional pain syndrome (altered CGRP signaling), cardiovascular disease (potential protective role), wound healing (promotes angiogenesis), and osteoarthritis (nerve growth and pain signaling). However, migraine remains by far the most clinically developed application of CGRP-targeted therapy.

References

  1. 1
    CGRP and migraine: from bench to bedside(2014)PubMed ↗
  2. 2
    Erenumab for the prevention of migraine: phase 3 STRIVE trial(2017)PubMed ↗
  3. 3
    CGRP receptor antagonists (gepants) in the acute treatment of migraine(2019)PubMed ↗
  4. 4
    Calcitonin gene-related peptide: physiology, pathophysiology, and therapeutic implications(2014)PubMed ↗

Latest Research

Last updated: 2026-02-19