| Zyrtec | Allegra | |
|---|---|---|
| Generic | cetirizine | fexofenadine |
| Active ingredient | Cetirizine HCl 10 mg | Fexofenadine HCl 180 mg (24 Hour) or 60 mg (12 Hour) |
| Type | Oral antihistamine (pill) | Oral antihistamine (pill) |
| Label uses | runny nose, sneezing, itchy, watery eyes, itching of the nose or throat | runny nose, sneezing, itchy, watery eyes, itching of the nose or throat |
| Nasal congestion on label | No | No |
| Drowsiness | May cause drowsiness | No drowsiness warning |
| How often | Once a day | Once a day (180 mg) or twice a day (60 mg) |
| Youngest age on label | 6 years | 12 years |
| Maximum | 1 tablet (10 mg) in 24 hours | 1 x 180 mg or 2 x 60 mg tablets in 24 hours |
The main differences
Both are oral antihistamines and list the same core uses on the label: itching of the nose or throat, itchy, watery eyes, runny nose, sneezing.
On drowsiness: Zyrtec: The label says "drowsiness may occur", and to avoid alcohol and be careful driving. Allegra: The label has no drowsiness warning.
For children, Zyrtec is labeled from age 6, while Allegra is labeled from age 12.
Dosing: Zyrtec is once a day; Allegra is once a day (180 mg) or twice a day (60 mg).
Which might suit you
- you want a single daily pill
- it is for a child aged 6 or older
- you need to stay alert during the day
- you can take it with water rather than juice and away from antacids
This is based only on what the two labels say. Neither label claims to work better than the other. A pharmacist can help if you have other conditions or take other medicines.
Dose by age
Zyrtec
- Adults and children 6 years and over: One 10 mg tablet once daily. Do not take more than one 10 mg tablet in 24 hours. The label notes a 5 mg product may be appropriate for less severe symptoms.
- Adults 65 and over: Ask a doctor.
- Children under 6: Ask a doctor.
- Liver or kidney disease: Ask a doctor.
Allegra
- Adults and children 12 and older (24 Hour): One 180 mg tablet with water once a day. Not more than 1 tablet in 24 hours.
- Adults and children 12 and older (12 Hour): One 60 mg tablet with water every 12 hours. Not more than 2 tablets in 24 hours.
- Children under 12: Do not use (these tablets).
- Adults 65 and older, or kidney disease: Ask a doctor.
Key warnings
Zyrtec
- Do not use if you have ever had an allergic reaction to this product or any of its ingredients, or to an antihistamine containing hydroxyzine.
- Ask a doctor before use if you have liver or kidney disease.
- Ask a doctor or pharmacist before use if you take tranquilizers or sedatives.
- If breast-feeding: not recommended. If pregnant: ask a health professional before use.
Allegra
- Do not use if you have ever had an allergic reaction to this product or any of its ingredients.
- Ask a doctor before use if you have kidney disease.
- Do not take at the same time as aluminum or magnesium antacids.
- Do not take with fruit juices: take it with water.
Compare prices for Zyrtec Compare prices for Allegra
Frequently asked questions
Is Zyrtec or Allegra better?
Neither label claims to work better than the other. Which suits you depends on your symptoms, age, and whether drowsiness matters, as compared above. A pharmacist can help you choose.
Can you take Zyrtec and Allegra together?
Both are antihistamines, and the labels don't cover combining them. Ask a pharmacist or doctor before combining allergy medicines.
Sources: Zyrtec Drug Facts label (Drugs.com, from the manufacturer's label); Allegra Allergy Drug Facts label (Drugs.com, from the manufacturer's label). Checked October 17, 2026. Not medical advice. How we check.