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Key takeaways
Zyrtec and Claritin are over-the-counter antihistamines that relieve allergy symptoms, but Zyrtec works faster.
Both medications treat seasonal and perennial allergic rhinitis and hives, but should not be used together.
They have similar side effects, but Zyrtec may cause more drowsiness.
Zyrtec (cetirizine) and Claritin (loratadine) are allergy medications used to treat symptoms of hay fever or allergic rhinitis, such as sneezing and a runny nose. As antihistamines, they block the effects of a chemical called histamine after contact with an allergen like pollen or pet dander. Both over-the-counter (OTC) drugs come in brand-name and generic forms, but they can differ in various ways, such as how fast they work and potential side effects.
What are the main differences between Zyrtec and Claritin?
The active ingredient and generic name of Zyrtec is cetirizine hydrochloride. It is generally used to treat allergy symptoms in adults and children over 2 years of age. Zyrtec has a quick onset of action, with relief usually felt within 20 minutes to an hour. Although Zyrtec and Claritin are considered non-drowsy antihistamines compared to older ones like Benadryl (diphenhydramine), Zyrtec may still cause sleepiness in many people.
Claritin, on the other hand, is known by its generic name, loratadine. While it is effective against allergy symptoms, it has a slower onset of action than Zyrtec, usually around one to three hours. However, Claritin is less likely to cause sedation than Zyrtec. Most Claritin products are FDA approved for adults and children two years and older, depending on the dosage form.
Main differences between Zyrtec vs. Claritin |
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|---|---|---|
| Zyrtec | Claritin | |
| Drug class | Antihistamine (second-generation) | Antihistamine (second-generation) |
| Brand/Generic status | Brand and generic available | Brand and generic available |
| Generic name | Cetirizine | Loratadine |
| What form(s) does the drug come in? | Tablet
Capsule Chewable tablet Syrup Orally disintegrating tablet |
Tablet
Capsule Chewable tablet Syrup Orally disintegrating tablet |
| What is the standard dosage? | 5 to 10 mg once daily in adults. Dosage may vary in children | 10 mg once daily or 5 mg twice daily in adults. Dosage may differ in children |
| How long is the typical treatment? | Short-term or long-term, depending on the severity and type of allergy | Short-term or long-term, depending on the severity and type of allergy |
| Who typically uses the medication? | Adults and children 2 years and older, depending on the dosage form | Adults and children 2 years and older, depending on the dosage form |
Conditions treated by Zyrtec and Claritin
Over-the-counter antihistamines like Zyrtec and Claritin can be used to treat symptoms of perennial (year-round) and seasonal allergies, including sneezing, runny nose, postnasal drip, and itchy, watery eyes. They’re also approved for chronic hives (urticaria).
Both Zyrtec and Claritin are available in formulations that contain the decongestant pseudoephedrine to help relieve nasal congestion. Neither is recommended to treat symptoms of non-allergic conditions, such as the common cold or bacterial infections.
Is Zyrtec or Claritin more effective?
Clinical trials have shown that Zyrtec and Claritin are both effective for allergy symptoms when compared to a placebo or nothing at all. However, some studies show that Zyrtec acts more quickly and may be more effective than Claritin.
An extensive analysis of 13 clinical trials with nearly 7,000 people found that cetirizine improved allergy-related quality of life more than loratadine. Compared with placebo, Zyrtec showed a larger average improvement (around a 0.62-point drop in symptom impact vs. about 0.32 points with Claritin).
The best allergy medication depends on your symptoms and how you respond to the drug. In some cases, you may need to try a different medicine if one isn’t working well enough.
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Coverage and cost comparison of Zyrtec vs. Claritin
Zyrtec and Claritin are not usually covered by Medicare or insurance because they are OTC. Still, a SingleCare coupon can help lower costs if a doctor or healthcare provider prescribes Zyrtec or Claritin.
Zyrtec vs. Claritin coverage and cost |
||
|---|---|---|
| Zyrtec | Claritin | |
| Typically covered by insurance? | No | No |
| Typically covered by Medicare? | No | No |
| Quantity | 30, 10 mg tablets | 30, 10 mg tablets |
| SingleCare cost | $3 at Walgreens | $4 at Walgreens |
Common side effects of Zyrtec vs. Claritin
Most side effects with these antihistamines are mild and temporary, with many people experiencing no side effects. Potential side effects include:
- Drowsiness
- Fatigue
- Headache
- Dry mouth
- Dizziness
- Nausea
- Diarrhea or constipation
Both drugs cause less drowsiness than older antihistamines, but it’s still a possible effect. Still, Zyrtec is known to cause more drowsiness than Claritin.
Serious side effects are rare but may include allergic reactions, irregular heartbeat, or severe dizziness.
Drug interactions and warnings of Zyrtec vs. Claritin
Zyrtec and Claritin should be used with caution when taken with certain medications that slow the central nervous system (CNS). These antihistamines can amplify drowsiness and dizziness from CNS depressants, such as alcohol, benzodiazepines, barbiturates, opioids, and anticonvulsants.
Claritin is metabolized by liver enzymes, so it may interact with certain antibiotics, antifungals, and antiretrovirals. Zyrtec has fewer drug interactions overall since it’s not processed heavily in the liver.
Precautions:
- Consult a provider before use if you’re pregnant or breastfeeding
- Tell your provider about all your health conditions, including liver or kidney problems.
- Talk to your child’s provider before giving either medication to children.
Can children use Zyrtec and Claritin?
Yes, both Zyrtec and Claritin can be used by children, but the appropriate dosage can vary depending on the child’s age. Consult a healthcare provider before starting any new medication for your child.
Zyrtec vs. Claritin dosage for children |
||
|---|---|---|
| Age group | Zyrtec dosage | Claritin dosage |
| 2 to 5 years | 2.5 mg once daily (may increase to 5 mg once daily or 2.5 mg twice daily) | 5 mg once daily |
| 6 to 11 years | 5 to 10 mg once daily | 10 mg once daily |
Consult a healthcare provider for options for children under 2. In general, both allergy medicines should be taken as directed by the package label or a healthcare provider. If your child experiences severe side effects or allergic reactions, seek medical attention immediately.
Can you take Claritin and Zyrtec together?
No, you should not take Claritin and Zyrtec together. Taking both could lead to increased side effects, such as drowsiness, dizziness, and dry mouth, since they work in similar ways.
If you find that taking one doesn’t work well enough, you can try switching to the other one to see if it helps, but don’t take both drugs within the same 24-hour period. If switching from Claritin to Zyrtec or vice versa doesn’t provide the allergy relief you’re looking for, seek medical advice from an allergist or other healthcare professional.
Frequently asked questions about Zyrtec vs. Claritin
Are Zyrtec and Claritin the same?
No. Although they are both antihistamines, they contain different active ingredients.
Which works faster?
Zyrtec works in about 20 minutes to an hour, while Claritin may take 1 to 3 hours.
Which causes more drowsiness?
Zyrtec has a higher risk of sedation.
Can I use Zyrtec or Claritin while pregnant or breastfeeding?
Possibly. Both are generally considered low-risk, but consult your healthcare provider first.
Can I use Zyrtec or Claritin with alcohol?
No. Alcohol can increase sedating side effects.
Are Zyrtec or Claritin safe to take daily, year-round?
Yes. They can be used year-round but are often taken seasonally.
- Cetirizine, StatPearls (2024)
- Loratadine, StatPearls (2023)
- Choosing an over-the-counter allergy medication, Harvard Health Publishing (2020)
- Towards definitive management of allergic rhinitis: best use of new and established therapies, Allergy, Asthma & Clinical Immunology (2020)
- Comparative onset of action and symptom relief with cetirizine, loratadine, or placebo in an environmental exposure unit in subjects with seasonal allergic rhinitis: confirmation of a test system, Annals of Allergy, Asthma & Immunology (2001)
- Onset of action for the relief of allergic rhinitis symptoms with second-generation antihistamines, Allergy & Asthma Proceedings (2004)
- A network meta-analysis of randomized controlled trials focusing on different allergic rhinitis medications, American Journal of Therapeutics (2016)
- High-risks drug adverse events associated with Cetirizine and Loratadine for the treatment of allergic diseases: A retrospective pharmacovigilance study based on the FDA adverse event reporting system database, Clinical and Translational Allergy (2024)
- Randomized, placebo-controlled study of cetirizine and loratadine in children with seasonal allergic rhinitis, Allergy & Asthma Proceedings (2017)
- Metabolism of loratadine and further characterization of its in vitro metabolites, Drug Metabolism Letters (2009)
- What medicine can I take for allergies while I’m pregnant?, American College of Obstetricians and Gynecologists (2001)