medicationOTC supplementLevocetirizine (Xyzal) is FDA-approved and available both by prescription and over the counter in the US for allergic rhinitis and chronic urticaria
LevocetirizineBenefits, Dosage & Interactions
Also known as: Xyzal
Levocetirizine, also commonly known as Xyzal, is a second-generation antihistamine used to relieve symptoms associated with seasonal and perennial allergic rhinitis, as well as chronic idiopathic urticaria (hives). It is the (R)-enantiomer of cetirizine. It is typically taken in the evening.
How much Levocetirizine do people take?
5 mg once daily was the dose used in both cited randomized comparisons in chronic urticaria. Route reported: Oral tablet. Frequency reported: Once daily, typically in the evening. These are amounts documented in the cited studies and labels for Levocetirizine — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
See the full reported protocol and its sourcesResearched by DoseRoutine Research TeamReviewed for accuracy by Nicholas Alexander, RSE, SO, PMPLast updated Educational reference only — not medical advice. Always confirm dosing and safety decisions with a licensed clinician.
Evidence: Strong — 2 human randomized trials and regulatory approval on file.
Evidence strengthStrong · 4/4
PreclinicalStrong human evidence
2 human randomized trials and regulatory approval on file.
Plasma half-life
Not established
Typical timing
in the evening
Default unit
mg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
Reported for Levocetirizine in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Levocetirizine entry is written from. Each number matches an inline marker above.
- [1]Efficacy and safety of bilastine vs. levocetirizine for the treatment of chronic idiopathic urticaria: A multicenter, double-blind, double-dummy, phase III, non-inferiority, randomized clinical trialChen X, Han X, Cheng B, Li H, Liu L, Geng S, Li L, Li J, Guo Q, Zhang G, Fang H, Zhang J · Chinese Medical Journal · 2024 · Peer-reviewed · PMID 38557589
- [2]An Investigator-Blind Randomized Controlled Trial Comparing Effectiveness, Safety of Levocetirizine and Bepotastine in Chronic UrticariaSil A, Rahaman S, Mondal N, Ahmed SS, Tarafdar D, Patra AC, Roy S, Das NK · Indian Journal of Dermatology · 2021 · Peer-reviewed · PMID 35068500
- [3]Treatment of acute urticaria: A systematic reviewBadloe FMS, Grosber M, Ring J, Kortekaas Krohn I, Gutermuth J · Journal of the European Academy of Dermatology and Venereology · 2024 · Peer-reviewed · PMID 38420865
References & Evidence
Sources on this page that document Levocetirizine dosing, timing and safety.
- [1]U.S. National Library of Medicine View source
- [2]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Levocetirizine?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Levocetirizine, also commonly known as Xyzal, is a second-generation antihistamine used to relieve symptoms associated with seasonal and perennial allergic rhinitis, as well as chronic idiopathic urticaria (hives). It is the (R)-enantiomer of cetirizine. As a second-generation antihistamine, it is designed to be less sedating than older, first-generation antihistamines while still effectively managing allergy symptoms such as sneezing, runny nose, itchy watery eyes, and itching. Levocetirizine works by blocking the action of histamine, a substance in the body that causes allergic symptoms. It is available over-the-counter and by prescription in various forms, including tablets and oral solutions. (MedlinePlus, PubChem)
What does the research say about Levocetirizine?
Tap a section to expand.
Levocetirizine acts as a selective antagonist of H1-histamine receptors. When an allergen enters the body, it triggers the release of histamine from mast cells. Histamine then binds to H1 receptors on various cells, leading to the characteristic symptoms of allergic reactions such as inflammation, itching, sneezing, and increased mucus production. Levocetirizine works by binding to these H1 receptors, preventing histamine from attaching and thus blocking its effects. By competitively inhibiting histamine binding, levocetirizine reduces the immediate symptoms of allergies. Its selectivity for peripheral H1 receptors and limited ability to cross the blood-brain barrier contribute to its lower potential for sedation compared to first-generation antihistamines. (PubChem, DrugBank)
Source for this section: Sources for How does Levocetirizine work?: Jumps to this entry in the sources and references list at the end of the page.
The primary benefits of levocetirizine stem from its effectiveness in alleviating allergy-related symptoms. These include:
* **Relief from Allergic Rhinitis Symptoms:** Levocetirizine is effective in reducing sneezing, runny nose (rhinorrhea), nasal itching, and itchy, watery eyes associated with both seasonal allergic rhinitis (e.g., hay fever) and perennial allergic rhinitis (year-round allergies). (MedlinePlus)
* **Management of Chronic Idiopathic Urticaria (Hives):** It helps to reduce skin itching and the number and size of hives in individuals suffering from chronic idiopathic urticaria, where the cause of the hives is unknown. (FDA label)
* **Reduced Sedation:** As a second-generation antihistamine, levocetirizine generally causes less drowsiness compared to older antihistamines, allowing patients to maintain daily activities with fewer impairments. (DrugBank)
Clinical studies have consistently demonstrated the efficacy of levocetirizine in treating allergic conditions. For instance, a review published in Allergy, Asthma & Clinical Immunology highlighted levocetirizine's role as a potent and selective H1-antihistamine with proven efficacy in allergic rhinitis and chronic urticaria. The review noted its rapid onset of action and favorable safety profile. The FDA approved levocetirizine for the treatment of allergic rhinitis and chronic idiopathic urticaria based on data from multiple clinical trials showing significant improvement in symptoms compared to placebo. (FDA label, DrugBank) Meta-analyses, such as those summarized by Cochrane reviews related to antihistamines for allergic rhinitis, further support the effectiveness of second-generation antihistamines like levocetirizine in symptom control. Specific trials cited in its FDA label reported significant reductions in symptom scores for sneezing, rhinorrhea, nasal itching, and itchy watery eyes in patients with seasonal allergic rhinitis and significant improvements in pruritus severity and reduction in hive count in patients with chronic idiopathic urticaria. (FDA label)
While generally well-tolerated, levocetirizine can cause side effects. Common ones include:
* Drowsiness, fatigue, or tiredness
* Dry mouth
* Sore throat
* Nausea
* Diarrhea
* Headache
Less common but more serious side effects may include:
* Dizziness or lightheadedness
* Difficulty urinating or changes in urination frequency
* Palpitations or irregular heartbeat
* Allergic reactions (rash, itching/swelling, severe dizziness, trouble breathing)
* Vision problems
* Mood changes (e.g., restlessness, agitation, aggression, hallucinations) or sleep disturbances
Children may be more prone to drowsiness or, paradoxically, excitement. If any serious or persistent side effects occur, discontinuation and consultation with a healthcare professional are advised.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for What are the side effects of Levocetirizine?: Jumps to this entry in the sources and references list at the end of the page.
Several warnings and precautions should be considered before using levocetirizine:
* **Drowsiness Risk:** Although it is considered less sedating than first-generation antihistamines, levocetirizine can still cause drowsiness or fatigue in some individuals. Caution should be exercised when driving or operating machinery until you know how the medication affects you. (MedlinePlus)
* **Alcohol and CNS Depressants:** Concurrent use of alcohol or other central nervous system depressants (e.g., sedatives, tranquilizers) can increase the risk of drowsiness and impaired judgment. (FDA label)
* **Kidney Impairment:** Individuals with impaired kidney function may require a lower dose of levocetirizine, as the drug is primarily eliminated unchanged by the kidneys. Renal impairment can lead to increased drug levels and a higher risk of adverse effects. (FDA label)
* **Urinary Retention:** Use with caution in patients with predisposing factors for urinary retention (e.g., spinal cord lesion, prostatic hyperplasia), as antihistamines can worsen these conditions. (EMA SmPC)
* **Pediatric Use:** In children younger than 6 years of age, specific dosage forms and concentrations should be used, and dosing should follow healthcare provider instructions carefully. (FDA label)
* **Elderly Use:** Older adults may be more susceptible to the side effects of antihistamines, including confusion, drowsiness, and urinary retention. (MedlinePlus)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for Who should avoid Levocetirizine?: Jumps to this entry in the sources and references list at the end of the page.
Levocetirizine is contraindicated in the following situations:
* **Hypersensitivity:** Individuals with a known hypersensitivity to levocetirizine, cetirizine, hydroxyzine, or any of the excipients in the formulation should not use this medication. (FDA label)
* **End-stage Renal Disease or Hemodialysis:** Patients with end-stage renal disease (creatinine clearance less than 10 mL/min) or those undergoing hemodialysis should not use levocetirizine due to significantly impaired clearance and increased risk of accumulation. (FDA label)
* **Infants and Young Children:** The oral solution, containing levocetirizine, is contraindicated in infants less than 6 months of age. There is insufficient safety data for this age group, and the risk of adverse effects outweighs any potential benefits. (FDA label)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for When should Levocetirizine not be taken?: Jumps to this entry in the sources and references list at the end of the page.
Certain substances can interact with levocetirizine, potentially altering its effects or increasing the risk of side effects. It is important to avoid or use with caution with:
* **Alcohol:** Concomitant use with alcohol can significantly increase impairment of the central nervous system, leading to enhanced drowsiness, dizziness, and decreased alertness. (FDA label)
* **Central Nervous System (CNS) Depressants:** Medications that also cause drowsiness or sedation (e.g., sedatives, tranquilizers, opioid pain relievers, muscle relaxants, other antihistamines, sleeping pills, anxiolytics) can intensify the sedative effects of levocetirizine. (MedlinePlus)
* **Ritonavir:** Although not a contraindication, co-administration with ritonavir (an antiviral medication) has been shown to increase plasma levels of desloratadine (another antihistamine related to levocetirizine), suggesting a potential for similar interactions that could increase levocetirizine exposure. Consultation with a healthcare provider is recommended. (DrugBank)
* **Theophylline:** Theophylline, a bronchodilator, can slightly decrease the clearance of levocetirizine. While usually not clinically significant, patient monitoring might be advised. (DrugBank)
Always inform your healthcare provider about all medications, supplements, and herbal products you are taking to prevent potential adverse interactions.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for What should you not mix with Levocetirizine?: Jumps to this entry in the sources and references list at the end of the page.
Levocetirizine is typically taken once daily. For most adults and children over 6 years of age, the medication is often recommended to be taken at bedtime. This timing can help mitigate any potential drowsiness experienced during the day, as the half-life of levocetirizine is approximately 8 hours, meaning its effects will generally last throughout the next day. It can be taken with or without food. However, individual responses to medications can vary. Always follow specific instructions from a licensed clinician. (FDA label, MedlinePlus)
Source for this section: Sources for When should you take Levocetirizine?: Jumps to this entry in the sources and references list at the end of the page.
Put it into practice
Reading about Levocetirizine is the first step — DoseRoutine helps you act on it. These free tools turn what you just learned into a routine.
What interacts with Levocetirizine?
Frequently asked questions about Levocetirizine
Levocetirizine is the active (R)-enantiomer of cetirizine. This means that levocetirizine is essentially the purer, more active form of the drug, allowing for similar efficacy at potentially lower doses with a comparable safety profile. (PubChem, DrugBank)
Levocetirizine typically starts to relieve allergy symptoms within about an hour after taking a dose. Its effects usually last for 24 hours. (MedlinePlus)
Levocetirizine is an antihistamine primarily effective for allergic reactions. While some cold symptoms like runny nose and sneezing can overlap with allergy symptoms, levocetirizine will not treat the underlying viral cause of a cold. It might offer some symptomatic relief for specific, allergy-like cold symptoms but is not its primary indication. (MedlinePlus)
Levocetirizine can be used long-term for chronic conditions like perennial allergic rhinitis or chronic idiopathic urticaria under the guidance of a healthcare professional. Its safety profile for extended use has been established in clinical trials. (FDA label)
Levocetirizine is a medication, and interactions are possible with prescriptions, hormones, peptides and other supplements in the same routine. Because Levocetirizine is usually taken in the evening, most avoidable conflicts come from what else lands in that same window. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Levocetirizine with no sign-up.
Levocetirizine is typically taken in the evening. Ranges reported in the literature are not recommendations; use the dose your clinician or the product label gives you.
Combining a medication like Levocetirizine with TRT is usually a question of labs rather than a blanket yes or no: the ester, injection interval and any aromatase inhibitor all change the answer. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
Each peptide class carries its own profile against Levocetirizine: a healing peptide raises different questions than a GLP-1 agonist or a growth-hormone secretagogue. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
Published frequency for Levocetirizine varies by protocol and formulation, so the label or prescription is what sets it. It is typically taken in the evening. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
The effect of a missed dose of Levocetirizine depends on the protocol and formulation you are on. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For Levocetirizine the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
5 mg once daily was the dose used in both cited randomized comparisons in chronic urticaria. Route reported: Oral tablet. Frequency reported: Once daily, typically in the evening. These are amounts documented in the cited studies and labels for Levocetirizine — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
Which studies looked at Levocetirizine?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Efficacy and safety of montelukast-levocetirizine combination therapy in combined allergic rhinitis and asthma syndrome: a systematic review and meta-analysis(opens PubMed in a new tab)J Asthma · 2025 · PMID 39394937 · https://pubmed.ncbi.nlm.nih.gov/39394937/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- MedlinePlus(opens in a new tab)U.S. National Library of Medicine · medlineplus.gov/druginfo/meds/a607056.html
- PubChem CID 9955977(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/9955977
Verify at
Publisher search links for Levocetirizine. These are places to check the information — they are not citations, so they are not numbered.
- FDA-approved labeling (DailyMed)(publisher search, opens in a new tab)U.S. Food and Drug Administration · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- European Medicines Agency(publisher search, opens in a new tab)European Medicines Agency · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Levocetirizine?
Plain-text summary, safe to quote verbatim:
Levocetirizine, also commonly known as Xyzal, is a second-generation antihistamine used to relieve symptoms associated with seasonal and perennial allergic rhinitis, as well as chronic idiopathic urticaria (hives). It is the (R)-enantiomer of cetirizine. It is typically taken in the evening.
Source: DoseRoutine — https://doseroutine.com/library/levocetirizine
Levocetirizine cheat sheet
DoseRoutine cheat sheet · Medication
Levocetirizine
Levocetirizine, also commonly known as Xyzal, is a second-generation antihistamine used to relieve symptoms associated with seasonal and perennial allergic rhinitis, as well as chronic idiopathic urticaria (hives). It is the (R)-enantiomer of cetirizine.
Evidence
Strong
2 human randomized trials and regulatory approval on file.
Studied range
5 mg once daily was the dose used in both cited randomized comparisons in chronic urticaria
Route
Oral tablet
Frequency studied
Once daily, typically in the evening
Timing
in the evening
OTC supplementLevocetirizine (Xyzal) is FDA-approved and available both by prescription and over the counter in the US for allergic rhinitis and chronic urticaria
Key references
- Efficacy and safety of bilastine vs. levocetirizine for the treatment of chronic idiopathic urticaria: A multicenter, double-blind, double-dummy, phase III, non-inferiority, randomized clinical trial (2024)
- An Investigator-Blind Randomized Controlled Trial Comparing Effectiveness, Safety of Levocetirizine and Bepotastine in Chronic Urticaria (2021)
- Treatment of acute urticaria: A systematic review (2024)
Studied ranges, not dosing advice. Not medical advice — talk to a clinician. doseroutine.com/library/levocetirizine
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Levocetirizine — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/levocetirizine
What compounds are similar to Levocetirizine?
Others in the medication category or studied for the same goals.