CGRP
Calcitonin gene-related peptide, alpha-CGRP
Written by Aaron CuhaReviewed Sep 2026
Also known as: Alpha-CGRP, CGRP-1, Calcitonin gene-related peptide 1
An endogenous 37 residue neuropeptide the human body makes, and one of the best validated drug targets in neurology: four approved antibodies and a class of oral gepants work by blocking it. Given to humans in controlled experiments, CGRP itself induced migraine-like attacks in 10 of 13 patients against none on placebo.
Overview
CGRP is on this site for a reason that inverts the usual one. It is not a compound anybody should consider taking. It is the endogenous ligand whose blockade produced one of the genuine therapeutic successes of the last decade, and it is a clean worked example of the difference between a target and a therapy.
It is a 37 residue neuropeptide encoded by the CALCA gene, annotated in UniProt P06881 at residues 83 to 119, and it is one of the most potent vasodilators known. A second gene product, beta-CGRP, is a separate entry.
The approved drugs that act on this pathway all block it. The monoclonal antibodies are erenumab, which binds the CGRP receptor, and fremanezumab, galcanezumab and eptinezumab, which bind the peptide itself. The small-molecule receptor antagonists, known as gepants, include ubrogepant, rimegepant, atogepant and zavegepant, used for acute treatment, prevention or both. These are approved, prescribed medicines with large randomised trials behind them.
The size of that evidence base is real. In the phase 3 STRIVE trial, 955 patients with episodic migraine were randomised to erenumab 70 mg, 140 mg or placebo monthly for six months. Monthly migraine days fell by 3.2 and 3.7 days respectively against 1.8 on placebo, from a baseline of 8.3 days, and a 50% or greater reduction was achieved by 43.3% and 50.0% of patients against 26.6% on placebo.
That evidence belongs to those molecules and it belongs to blocking this peptide. It does not transfer to the peptide. When CGRP itself has been infused into humans in a double-blind, placebo-controlled, randomised crossover design, it induced migraine-like attacks in 10 of 13 migraine patients, compared with none after placebo, P = 0.002, with a median peak headache intensity of 5 against 2 on placebo.
There is no scenario in the published literature in which exogenous CGRP is given as a treatment for anything.
Mechanism of action
Demonstrated, and demonstrated in both directions, which is unusual. CGRP is released from trigeminal sensory neurons and acts at a receptor complex of calcitonin receptor-like receptor with receptor activity-modifying protein 1, producing potent vasodilation and pain signalling relevant to migraine. Giving it to humans provokes migraine attacks; blocking it, with an antibody against the peptide or the receptor or with an oral receptor antagonist, prevents and aborts them. Few targets in neurology have been validated from both ends of the same pathway in human experiments.
Human evidence
Extensive. It runs in two directions and neither direction supports taking CGRP. Blocking it prevents migraine in large randomised trials; administering it provokes migraine in controlled provocation experiments.
- Erenumab STRIVE, 955 patients randomised: monthly migraine days fell 3.2 and 3.7 on 70 mg and 140 mg against 1.8 on placebo from a baseline of 8.3; 50% or greater responders 43.3% and 50.0% against 26.6% (PMID 29171821).
- CGRP provocation, 13 migraine patients, double-blind placebo-controlled randomised crossover: migraine-like attacks in 10 of 13 after CGRP and 0 after placebo, P = 0.002; median peak headache intensity 5 against 2, P = 0.004 (PMID 30409109).
- Four CGRP-directed monoclonal antibodies are approved: erenumab, fremanezumab, galcanezumab and eptinezumab. Multiple oral gepants are approved: ubrogepant, rimegepant, atogepant and zavegepant.
- No trial has administered CGRP as a therapy for any indication. No trial has measured a cognitive endpoint with CGRP.
What this does not tell you: The human evidence here is about drugs that block CGRP. It tells you nothing about what taking CGRP would do, except through the provocation studies, which tell you it would probably give a migraine-prone person a migraine. Reading the strength of the antagonist evidence as though it supported the peptide is the specific error this entry exists to prevent.
Reading the research record
CGRP is an endogenous signalling peptide, not a research chemical and not a product. Printing not approved, research use only against a molecule the human body continuously produces would tell a reader something false, which is why this page uses the native ligand classification and names the approved drugs explicitly.
The pattern this page guards against is common in peptide marketing: a peptide has a large, impressive clinical literature, and that literature is about a drug which blocks it. Reading the citation count as an endorsement of the peptide gets the direction of the pharmacology exactly backwards. In this case the inversion is unusually clean, because the same research programme that produced the antibodies also ran the provocation studies, so both directions are measured in humans in the same field.
The practical statement is short. Nobody sells CGRP as a supplement and nobody should. If your interest is the migraine drug class, the molecules are erenumab, fremanezumab, galcanezumab, eptinezumab and the gepants, and they are prescription medicines with large phase 3 programmes behind them.
A cognitive endpoint is a measured one: a validated test of working memory, processing speed, attention, executive function or episodic recall, administered before and after, against a control group who did not know which arm they were in. None of the compounds in this batch has ever been tested that way. Rating scales of fatigue, global clinical impression, anxiety or hyperphagia are not cognitive endpoints, and neither is a hormone level. This matters because the marketing for several of these compounds describes focus, clarity and mental energy, and the underlying studies measured none of those things.
The evidence, charted
Fig. 1 · evidence composition
2of 4 citations (50%) are in people
Counted from the citation list on this page. The Human count is the same number shown in the badge at the top. Both understate any literature larger than the sources we cite.
Fig. 2 · evidence over time
Evidence spans 4 distinct years, 2017 to 2025, counted from the citation list on this page.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four jurisdictions shown. A jurisdiction's classification is a regulatory fact, not a verdict on the science; see Legal status below for the full text and any notes.
Key studies & citations
- Human2018
Migraine induction with calcitonin gene-related peptide in patients from erenumab trials
What happens when you give CGRP to a human. Thirteen migraine patients previously enrolled in erenumab trials received CGRP in a double-blind, placebo-controlled, randomised crossover design. CGRP induced migraine-like attacks in 10 of 13 patients (77%) compared with none after placebo, P = 0.002. Area under the curve for headache intensity was greater after CGRP at 0 to 90 minutes (P = 0.009) and 2 to 12 hours (P = 0.014), and median peak headache intensity was 5 against 2 on placebo (P = 0.004). Registered NCT03481400. The senior author discloses consultancy or advisory relationships with Allergan, Amgen, Alder, Eli Lilly, Novartis and Teva.
The Journal of Headache and Pain - Human2017
A Controlled Trial of Erenumab for Episodic Migraine
The scale of evidence behind blocking this peptide, not administering it. 955 patients randomised to subcutaneous erenumab 70 mg (n=317), 140 mg (n=319) or placebo (n=319) monthly for six months. From a baseline of 8.3 monthly migraine days, days fell by 3.2 and 3.7 respectively against 1.8 on placebo (P<0.001 for each dose). A 50% or greater reduction was reached by 43.3% and 50.0% against 26.6% on placebo. Adverse event rates were similar to placebo. Several authors are Amgen employees.
The New England Journal of Medicine - Review2025
Calcitonin gene-related peptide-targeted therapy in migraine: current role and future perspectives
A 2025 review of the CGRP-targeted drug class, describing the current clinical role of the monoclonal antibodies and gepants. Useful as the map of which approved molecules act on this pathway and how. It reviews blockade of CGRP; it does not describe any therapeutic use of CGRP itself.
The Lancet - Review2020
Calcitonin gene-related peptide (CGRP): role in migraine pathophysiology and therapeutic targeting
A review of the peptide's role in migraine pathophysiology and of the logic of targeting it. Establishes the framing that CGRP is a validated target rather than a candidate treatment.
Expert Opinion on Therapeutic Targets
Frequently asked questions
Can I take CGRP?
No, and you would not want to. In a double-blind placebo-controlled crossover experiment, infusing CGRP induced migraine-like attacks in 10 of 13 migraine patients against none on placebo. CGRP is a target that successful drugs block, not a therapy.
What drugs target CGRP?
Four approved monoclonal antibodies: erenumab, which binds the CGRP receptor, and fremanezumab, galcanezumab and eptinezumab, which bind the peptide. Plus the oral small-molecule receptor antagonists called gepants, including ubrogepant, rimegepant, atogepant and zavegepant, used for acute treatment, prevention or both.
Is CGRP a research chemical?
No. It is a peptide your own body makes, released from trigeminal sensory neurons, encoded by the CALCA gene and annotated at 37 residues. It is not a product, has no approval status of its own, and is not sold as a supplement.
How well do the CGRP blockers work?
In the phase 3 erenumab trial of 955 patients with episodic migraine, monthly migraine days fell by 3.2 days on 70 mg and 3.7 on 140 mg against 1.8 on placebo, from a baseline of 8.3 days. Half the patients on 140 mg achieved at least a 50% reduction, against about a quarter on placebo. That is a real effect, and a quarter of patients on placebo also halved their migraine days, which is why the placebo arm matters.
Does CGRP have anything to do with cognition or nootropics?
No controlled trial has measured a cognitive endpoint with CGRP or with the drugs that block it as a primary outcome. The endpoints in this field are migraine days, headache intensity and acute medication use.