Zyrtec, Claritin and Allegra are the three most popular second-generation (“non-drowsy”) oral antihistamines for hay fever and hives. All three are once-daily, available over the counter and as low-cost generics, and work in similar ways — so the right pick usually comes down to how fast it works, how likely it is to make you sleepy, and how your body responds.
There is no single “best” — for typical seasonal allergies the three are broadly comparable. Cetirizine (Zyrtec) often works fastest but is the most likely of the three to cause some drowsiness; loratadine (Claritin) is the least sedating; fexofenadine (Allegra) is genuinely non-drowsy but absorbs best on an empty stomach and shouldn't be taken with fruit juice.
| Zyrtec cetirizine | Claritin loratadine | Allegra fexofenadine | |
|---|---|---|---|
| Active ingredient | Cetirizine Hydrochloride | Loratadine | Fexofenadine Hydrochloride |
| Our rating | Not yet rated | 68/100(33) | Not yet rated |
| Typical price | $0.06 /mL | ~$1.60 /30 | ~$7.44 /30 |
| Onset | ~1 hour (often the fastest) | 1–3 hours | ~1–2 hours |
| Drowsiness | Low — but the most likely of the three to cause some | Lowest — least sedating of the three | Non-drowsy |
| Good to know | A good choice when you want quick relief; a minority of people feel mild sleepiness. | Best when staying fully alert is the priority; onset can be a little slower. | Take with water (not fruit juice, which lowers absorption), ideally on an empty stomach. |
Ratings are our independent FDA recall-safety score. General information, not medical advice.
Zyrtec (cetirizine)
A good choice when you want quick relief; a minority of people feel mild sleepiness.
Claritin (loratadine)
Best when staying fully alert is the priority; onset can be a little slower.
Allegra (fexofenadine)
Take with water (not fruit juice, which lowers absorption), ideally on an empty stomach.
All three relieve sneezing, runny nose, itchy/watery eyes and hives, and per MedlinePlus they share the same second-generation antihistamine class with a low risk of the heavy sedation seen with older antihistamines. Pick by practical fit: reach for Zyrtec (cetirizine) if you want the fastest relief and don't mind a small chance of drowsiness; Claritin (loratadine) if staying fully alert matters most; Allegra (fexofenadine) for reliably non-drowsy relief (take it with water, not juice, ideally on an empty stomach). If one doesn't work well for you, it's reasonable to try another — response varies by person. This is general information, not medical advice; ask a pharmacist or doctor if you're pregnant, take other medicines, or have a health condition.