Cetirizine dihydrochloride

≥98% (HPLC)

[2-[4-[(4-Chlorophenyl)phenylmethyl]-1-piperazinyl]ethoxy]acetic acid dihydrochloride
Empirical Formula (Hill Notation):
C21H25ClN2O3 · 2HCl
CAS Number:
Molecular Weight:
MDL number:
PubChem Substance ID:

Quality Level


≥98% (HPLC)




white to beige


H2O: 5 mg/mL, clear



relevant disease(s)


SMILES string




InChI key


Gene Information

human ... HRH1(3269)

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Cetirizine dihydrochloride has been used as an antagonist for histamine receptors H1 in HSDSEAP (poly) clonal cells derived from human embryonic kidney HEK-293 cells. It has also been used as a ligand in the crystallization of equine serum albumin cetirizine complex.


50, 250 mg in glass bottle

Biochem/physiol Actions

Cetirizine hydrochloride is an orally active and selective H1-receptor antagonist. Antihistaminic; Piperazines. Non-sedating type histamine H1-receptor antagonist; major metabolite of hydroxyzine. Pharmacological activity resides primarily in the (R)-isomer.
Cetirizine is a racemic mixture of (R)-levocetirizine and (S)-dextrocetirizine. It exists as a zwitterion at acidic pH and gets absorbed by passive diffusion. Cetirizine is a prescribed drug for allergic rhinitis and chronic idiopathic urticaria.

Features and Benefits

This compound is also offered as part of Sigma′s Library of Pharmacologically Active Compounds (LOPAC®1280), a biologically annotated collection of high-quality, ready-to-screen compounds. Click here to learn more.
This compound was developed by Pfizer. To browse the list of other pharma-developed compounds and Approved Drugs/Drug Candidates, click here.
This compound is featured on the Histamine Receptors page of the Handbook of Receptor Classification and Signal Transduction. To browse other handbook pages, click here.
This compound is a featured product for ADME Tox research. Click here to discover more featured ADME Tox products. Learn more about bioactive small molecules for other areas of research at sigma.com/discover-bsm.

Legal Information

LOPAC is a registered trademark of Sigma-Aldrich Co. LLC


Exclamation mark

Signal Word


Hazard Statements


Acute Tox. 4 Oral


13 - Non Combustible Solids

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves

Certificate of Analysis

Certificate of Origin

Crystal structure of equine serum albumin in complex with cetirizine reveals a novel drug binding site
Handing K, et al.
Molecular Immunology, 71, 143-151 (2016)
A designer cell-based histamine-specific human allergy profiler
Auslander D, et al.
Nature Communications, 5, 4408-4408 (2014)
Compared pharmacological characteristics in humans of racemic cetirizine and levocetirizine, two histamine H1-receptor antagonists
Tillement JP, et al.
Biochemical Pharmacology, 66(7), 1123-1126 (2003)
Benno Brinkhaus et al.
Annals of internal medicine, 158(4), 225-234 (2013-02-20)
Chinese translation Acupuncture is frequently used to treat seasonal allergic rhinitis (SAR) despite limited scientific evidence. To evaluate the effects of acupuncture in patients with SAR. Randomized, controlled multicenter trial. (ClinicalTrials.gov: NCT00610584) 46 specialized physicians in 6 hospital clinics and...
Agnieszka Biedroł et al.
Pediatrics, 133(4), e1068-e1071 (2014-03-26)
The occurrence of stabbing headaches in children requires a thorough diagnostic approach that excludes secondary headaches. The organic background should be taken into consideration when alarming symptoms occur, such as a purely 1-sided location, a change in the character of...
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