Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library
Icatibant (Firazyr): what the evidence says
At a glance
What it is: a synthetic 10-amino-acid bradykinin B2 receptor blocker. FDA approved Firazyr (NDA 022150, Takeda); generics exist. R1
What the evidence says: in FAST-2, symptoms eased in 2.0 hours vs 12.0 with tranexamic acid; FAST-1 missed significance vs placebo (2.5 vs 4.6 hours). R2 FAST-3 confirmed faster relief vs placebo (2.0 vs 19.8 hours). R3 Patients can inject it themselves. R4
Biggest risks: injection-site reactions. UNVERIFIED the label's injection-site reaction rate.
Rating
| Human Human evidence | Strong: FAST-1, -2, -3 RCTs, n = 56 to 98 R2, R3 |
| Animal Animal / lab evidence | Not reviewed |
| Regulatory | FDA-approved (NDA 022150) R1 · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page R5, R6, R7 · not named by WADA R8 |
| Established human dose | Yes, label dose |
Evidence verdict: Acute hereditary angioedema attacks: Strong (FDA-approved, three phase 3 RCTs) · Other uses: Limited
This page reports what studies used. It is not dosing advice.
Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source
About the evidence: three randomized trials; FAST-1 alone was not significant, likely because many placebo patients improved and needed rescue.
What is it?
Does it work?
- Human FAST-1/FAST-2: faster relief; fewer rescue treatments (3 vs 13 in FAST-1). R2
- Human FAST-3: median 2.0 vs 19.8 hours to 50% symptom relief. R3
- Human Self-injection: works at home. R4
Is it safe?
- Human Generally well tolerated in trials; mostly local reactions. R3
Gray-market vials: extra risks
A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe.
Is it legal?
- US: FDA-approved prescription drug. R1
- Compounding: not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. R5, R6, R7
- Sport: not named on WADA's 2026 Prohibited List. R8
Study details
Study details
These are amounts researchers used, not recommendations.
| Study | People / model | Route | Amount used | Follow-up | Reported | Citation |
|---|---|---|---|---|---|---|
| FAST-1/FAST-2 2010 | 56 and 74 patients | SC single | 30 mg | Per attack | 2.5 vs 4.6 h; 2.0 vs 12.0 h | PMID 20818888 |
| FAST-3 2011 | 98 patients | SC single | 30 mg | Per attack | 2.0 vs 19.8 h | PMID 22123383 |
Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 26, 2026)
- R1 Drugs@FDA, Firazyr (icatibant), application NDA 022150 (openFDA drugsfda record checked Oct 26, 2026). https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=NDA 022150
- R2 Cicardi M, et al. N Engl J Med. 2010. PMID 20818888
- R3 Lumry WR, et al. Ann Allergy Asthma Immunol. 2011. PMID 22123383
- R4 Aberer W, et al. Allergy. 2014. PMID 24438203
- R5 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
- R6 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
- R7 FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
- R8 WADA. The 2026 Prohibited List, full list checked; compound not named. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
Disclaimer
This page is for education and harm reduction, not medical advice or a recommendation to use Icatibant (Firazyr). This is a prescription medicine. Use it only under the care of a licensed clinician; do not buy it from research-chemical or gray-market sellers. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).