What Claritin is
Claritin is the brand name for loratadine, a second-generation antihistamine. It blocks histamine at H1 receptors, which calms sneezing, itching and a runny nose. The item we link to is Claritin 24 Hour, loratadine 10 mg tablets, 70 count.
The label covers adults and children 6 and up: one 10 mg tablet once a day, and no more than one in 24 hours. Like other modern antihistamines, loratadine was designed to stay mostly out of the brain, which is why it rarely causes drowsiness.
How well it works
Loratadine works better than a placebo. A 2026 network meta-analysis for the ARIA guideline panel found that the major second-generation antihistamines improve allergic rhinitis symptoms. It also found that most differences between them are small, and the certainty of those comparisons was often low PMID: 41707943.
Where there is a difference, loratadine tends to come out behind. In a head-to-head outdoor study during pollen season, cetirizine relieved symptoms faster and more completely than loratadine PMID: 8621847. A separate network meta-analysis of 18 randomized trials ranked loratadine 10 mg lowest of the antihistamines it compared, though every one of them beat placebo PMID: 37271114.
Expect relief within 1 to 3 hours. For seasonal allergies, it works best when you take it every day through the season.
What it treats well: sneezing, runny nose, and itchy nose and eyes, especially when symptoms are mild.
What it doesn't treat well: a blocked, stuffy nose. Steroid nasal sprays such as Flonase relieve congestion better than antihistamine pills PMID: 9848901.
Drowsiness and other side effects
Low drowsiness is Claritin's main strength. In four prescription-monitoring studies covering more than 43,000 patients, sedation was reported about 3.5 times more often with cetirizine than with loratadine. Fexofenadine and loratadine did not differ significantly PMID: 10784544. The authors concluded that loratadine and fexofenadine may be the better fit for people in safety-critical jobs.
Practical tips:
- Don't take more than one tablet in 24 hours.
- Ask a clinician first if you have liver or kidney disease; you may need a different dose.
- Ask a clinician or pharmacist if you are pregnant or breastfeeding.
- Skip "Claritin-D" unless a clinician says it's fine. The "D" adds pseudoephedrine, a decongestant that slightly raised systolic blood pressure and heart rate in a meta-analysis of trials PMID: 16087815.
Claritin vs. generic loratadine
The drug and dose are the same. Generic loratadine must meet the FDA's bioequivalence standard, which requires it to deliver the same drug exposure as the brand within tight statistical limits PMID: 11515710. Our estimate for brand Claritin is $15–20 a month. The generic loratadine we link to costs about $2–4 a month. Unless you have a known reaction to an inactive ingredient in a particular generic, there's little reason to pay for the brand.
Who should buy it
Buy Claritin if your symptoms are mild, you're sensitive to drowsiness, and you prefer the brand.
Buy generic loratadine instead if you want the same medicine for much less.
Choose Allegra if you need stronger relief without drowsiness; it matched cetirizine's relief in a head-to-head trial PMID: 14582814. Choose Zyrtec or generic cetirizine if you want the strongest relief and drowsiness isn't a problem. Add Flonase or Nasacort if congestion is your main complaint.
See how it compares with the other options in our Best Allergy Medicines roundup.