NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated July 13, 2026

Cetirizine

Prescription ·Exploratory record · not publication-reviewed ·Updated July 13, 2026

A second-generation (non-sedating) antihistamine used for the relief of symptoms associated with seasonal and perennial allergic rhinitis and chronic idiopathic urticaria. The active carboxylate metabolite of hydroxyzine, cetirizine has minimal CNS penetration compared to first-generation antihistamines, though it is slightly more sedating than other second-generation agents (loratadine, fexofenadine). Available over-the-counter.

Evidence tier
Strong
Indexed sources
11 2005–2024
Interactions
0
Category
Prescription
Read the sources → Compare profiles
Publication status

Exploratory record, not a reviewed medical publication.

See the editorial and medical-review policies for the publication gate.

This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.

In short

What the research says.

A quick, data-only summary. The full evidence, dosing, and sources are below.

A second-generation (non-sedating) antihistamine used for the relief of symptoms associated with seasonal and perennial allergic rhinitis and chronic idiopathic urticaria. NutriStack rates the supporting evidence as strong. Common adult dosing is Adults and children >=6 years: 5-10 mg once daily; children 2-5 years: 2.5 mg daily (may increase to 5 mg/day); some patients benefit from 5 mg BID (as prescribed by your physician), though a prescriber sets the actual dose. This profile indexes 11 sources.

What it's good for
  • Relieves sneezing, rhinorrhea, itchy/watery eyes
  • Treats seasonal and perennial allergic rhinitis5,6
  • Treats chronic idiopathic urticaria (hives)10
  • Once-daily dosing
  • Rapid onset of action (within 1 hour)
What to watch for
  • Drowsiness/somnolence (more common than other second-gen antihistamines, ~14%)
  • Dry mouth
  • Fatigue
  • Known hypersensitivity to cetirizine, hydroxyzine, or any component1,2
  • End-stage renal disease (on dialysis)2,7

The bottom line

Evidence rating strong. Most-documented uses: relieves sneezing, rhinorrhea, itchy/watery eyes, treats seasonal and perennial allergic rhinitis, treats chronic idiopathic urticaria (hives). 11 sources indexed (2005–2024), with 0 interaction records on file.

The science

How it works, mechanistically.

Core mechanism

Selectively and competitively blocks peripheral H1 histamine receptors with minimal anticholinergic and anti-serotonergic effects. Inhibits the early-phase allergic response by preventing histamine from binding to H1 receptors on smooth muscle, vascular endothelium, and sensory nerve endings. Also inhibits eosinophil chemotaxis and late-phase allergic inflammatory mediator release at therapeutic doses. Minimal CNS penetration due to its zwitterionic properties and P-glycoprotein efflux at the blood-brain barrier.

Class
Second-Generation Antihistamine
Dosing

Dosing & protocol.

Common range
Adults and children >=6 years: 5-10 mg once daily; children 2-5 years: 2.5 mg daily (may increase to 5 mg/day); some patients benefit from 5 mg BID (as prescribed by your physician)
Recommended form
Oral tablets, chewable tablets, oral solution, or liquid gels

Rapidly absorbed with bioavailability >70%. Food delays but does not reduce total absorption. Can be taken with or without food. May cause more drowsiness than loratadine or fexofenadine.

Safety

Full safety detail.

Side effects

  • Drowsiness/somnolence (more common than other second-gen antihistamines, ~14%)
  • Dry mouth
  • Fatigue
  • Headache
  • Pharyngitis
  • Abdominal pain

Contraindications

  • Known hypersensitivity to cetirizine, hydroxyzine, or any component1,2
  • End-stage renal disease (on dialysis)2,7
  • Severe hepatic impairment (dose reduction required)
  • Children under 6 months2,5
Sources

Sources, by evidence tier.

Numbered references. Citations throughout the page link here.

Meta-analyses & systematic reviews

4

Randomized controlled trials

2

Reviews & position papers

1

Reference material

4
FAQ

Common questions.

Quick answers about Cetirizine, drawn from the data on this page.

What is Cetirizine?

A second-generation (non-sedating) antihistamine used for the relief of symptoms associated with seasonal and perennial allergic rhinitis and chronic idiopathic urticaria. The active carboxylate metabolite of hydroxyzine, cetirizine has minimal CNS penetration compared to first-generation antihistamines, though it is slightly more sedating than other second-generation agents (loratadine, fexofenadine). Available over-the-counter.

What is Cetirizine used for?

Commonly cited benefits of Cetirizine include: Relieves sneezing, rhinorrhea, itchy/watery eyes; Treats seasonal and perennial allergic rhinitis; Treats chronic idiopathic urticaria (hives); Once-daily dosing; Rapid onset of action (within 1 hour). NutriStack rates the overall evidence as strong.

What is a typical dose of Cetirizine?

A typical adult dose of Cetirizine is Adults and children >=6 years: 5-10 mg once daily; children 2-5 years: 2.5 mg daily (may increase to 5 mg/day); some patients benefit from 5 mg BID (as prescribed by your physician). The commonly recommended form is Oral tablets, chewable tablets, oral solution, or liquid gels. These are general ranges, not personalized advice; confirm the right dose with a clinician.

What are the side effects of Cetirizine?

Reported side effects include drowsiness/somnolence (more common than other second-gen antihistamines, ~14%), dry mouth, fatigue, headache, pharyngitis, abdominal pain. This is educational information; check with a healthcare professional before use.

How strong is the evidence for Cetirizine?

NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.

Use this with your stack

Cetirizine in NutriStack.

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NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.