Loratadine vs Cetirizine: Which Is The Best Antihistamine?

More than 100 million people have allergies in the United States, making it the sixth leading cause of chronic illness nationwide.

Seasonal allergies are the most common type of allergy, which occurs when different types of pollen and grasses are the most active. 

You’re most likely to have respiratory symptoms (also called allergic rhinitis) with seasonal allergies.

If you’re miserable with itchy, watery eyes, sneezing, and other symptoms, you might reach for an allergy medication. 

Loratadine and Cetirizine (Claritin and Zyrtec) are two common allergy medications that we’ll compare head-to-head in this article.

Are Loratadine and Cetirizine the same? 

Loratadine (brand name Claritin) and Cetirizine (brand name Zyrtec) are not the same medication but work similarly. Both are antihistamines, which help reduce allergy symptoms.

Get Your FREE Eye Health Diet Plan

  • Nine most important vitamins for eye health
  • How to naturally protect and improve your eye health as you age
  • Developed exclusively by our medical doctor

By clicking “Download Now”, I agree to Ben's Natural Health Terms and Conditions and Privacy Policy.

Differences between Loratadine vs Cetirizine

1) Approval dates and OTC dates

Loratadine was first approved by the Food and Drug Administration in 1993 and required a prescription up until 2002, when it went off-patent. 

Cetirizine was first approved by the FDA in 1995 and was made available as an over-the-counter (OTC) medication in 2007.

2) Action time

Loratadine doesn’t start to work as quickly as Zyrtec, which begins working around an hour after you take it (according to the manufacturer).

3) Side effects

Cetirizine is more likely to make you feel sleepy compared to loratadine, even though both medications are considered non-drowsy. 

Here is a comparison of the common side effects:

Name of side effectPotential side effect of LoratadinePotential side effect of Cetirizine
DrowsinessNot as common as with Zyrtec, but possibleYes (even though it’s considered non-drowsy)
Dry mouthYesYes
Diarrhea/upset stomachYesYes
Sore throatYesYes

4) Symptom relief

According to the manufacturer of Zyrtec (cetirizine), Zyrtec doesn’t provide relief for nasal congestion, while loratadine (Claritin) DOES help nasal congestion.

Also, according to the manufacturer of Zyrtec, Zyrtec helps provide relief for an itchy throat and itchy, watery eyes, while Claritin does NOT.

5) Dosing

Both loratadine and cetirizine are typically taken once per day, though children can take two doses a day of the children’s version of cetirizine (but not to exceed the maximum recommended dose in 24 hours).

Similarities between Zyrtec and Claritin

1) Both second-generation medications

Loratadine (Claritin) and Cetirizine (Zyrtec) are both considered  “second-generation” antihistamines, which work to block histamine receptors and help reduce allergy symptoms. 

Unlike first-generation antihistamines, which cross the blood-brain barrier, second-generation antihistamines do NOT cross the blood-brain barrier. 

That means it crosses a “filter” of sorts that your brain uses to protect itself against potentially harmful substances.

2) Both are oral medications

You can find Zyrtec and Claritin in tablet form as well as a liquid suspension. They are also available in oral disintegrating tablets (depending on the manufacturer), which don’t have to be swallowed like regular tablets.

3) Minimum age

Both Zyrtec and Claritin can be used in children as young as two years old, but not younger (unless advised or prescribed by a healthcare provider). 

You should always ask your child’s healthcare provider which dose is safest for your child, given their age and weight. 

4) Relief time

Both medications are marketed as offering 24-hour relief, which means you only take one dose in 24 hours. 

However, cetirizine begins to work more quickly than loratadine, according to its manufacturer.

clear vision supplement

What is the best antihistamine?

Studies suggest a slightly higher efficacy for Cetirizine, but both antihistamines are effective at reducing allergy symptoms.

Studies show Cetirizine is slightly more effective than Loratadine

Cetirizine was found to be better than loratadine at reducing seasonal allergy symptoms in children aged 6-11 when compared against each other in a study.

Another study on 90 patients suffering from moderate to severe allergy symptoms found that both cetirizine and loratadine were effective at reducing symptoms, though cetirizine was slightly better (but not enough to be considered significant).

Finally, a study concluded that cetirizine is “seven to nine times more potent than loratadine” at preventing rash and hive reactions.

Studies show Zyrtec has less drowsiness than Claritin

Regarding drowsiness, a study found that patients taking loratadine experienced less drowsiness and reduced motivation compared to cetirizine.

Bottom line

What does this all mean in terms of which is the best antihistamine? It depends on your symptoms and what kind of side effects you’re willing to endure.

For instance, if you prefer a medication that is less likely to make you drowsy, then loratadine is likely the better choice. 

If you have itchy, watery eyes or an itchy throat, cetirizine is more likely to help treat those symptoms, whereas loratadine is better at treating nasal congestion.

If your symptoms are bothersome and include hives and rashes – and you don’t mind the possibility of drowsiness – then cetirizine is likely a better option since it appears to be more potent and targets skin reactions better than loratadine.


Can you take cetirizine at night and loratadine in the morning?

It’s generally not recommended to take two types of antihistamines within the same 24-hour period, especially since both medications are meant to be taken once daily.

While there aren’t any interactions between the two medications (since they are in the same drug class), taking cetirizine at night and loratadine in the morning would essentially be like taking double the recommended dose in 24 hours.

Unless your healthcare provider recommends that you take cetirizine at night and loratadine in the morning, you shouldn’t take both in the same 24-hour period.

If you find that one medication works better than the other, then wait 24 hours until your last dose before switching from one to the other.

Which is cheaper, Zyrtec or Claritin?

According to the price for generic versions of both medications at Target (a popular store with a pharmacy in the United States), 30 generic loratadine tablets (10 milligrams each) cost around $6, while 30 generic cetirizine tablets (10 milligrams each) costs $7.

That means that the price is very similar, with cetirizine costing slightly more (around 33 cents more per tablet than loratadine).

The price of Loratadine vs Cetirizine will vary depending on the dose, quantity of tablets, type (generic vs name brand), store, and whether you have any coupons to make the medication cheaper.

Which has fewer side effects, Loratadine or Cetirizine?

Both medications come with the potential for side effects. The main difference in terms of side effects is that loratadine is less likely to cause drowsiness compared to cetirizine, which can be a major factor when you’re considering which medication to choose.

What’s the safest antihistamine for long-term use?

If you need to take an antihistamine for long-term use, you should do so under the guidance of your healthcare provider.

In general, non-sedating antihistamines without added decongestants are generally suitable for longer-term use, especially compared to first-generation antihistamines.

According to a study, both loratadine and cetirizine are generally considered safe when used as directed.

The study notes that cetirizine “has been shown to impair performance and cognition in several studies, although to a much lesser degree than older antihistamines”, which is one thing to consider. 

Which allergy medicine is the strongest?

Loratadine and cetirizine both come in 10-milligram doses, so they are considered equal in strength. 

However, as mentioned earlier, studies have found that cetirizine seems to appear slightly more potent than loratadine in its ability to reduce allergy symptoms.

You might find that one allergy medication works better for you than the other. 

You should choose the medication that seems to work the best for your symptoms while having the fewest side effects.


  • Loratadine (brand name Claritin) and cetirizine (brand name Zyrtec) are both second-generation over-the-counter antihistamines.
  • Both medications carry similar side effects, though loratadine is less likely to cause drowsiness than cetirizine. 
  • Both medications are considered “non-drowsy,” unlike other types of allergy medications like diphenhydramine (Benadryl).
  • According to studies, cetirizine appears to be slightly more effective in terms of reducing symptoms, but both medications are good at reducing allergy symptoms.
  • Which medication is better depends on the types of symptoms you want to treat and the side effects you’re willing to endure potentially (e.g., drowsiness).

Explore More

diabetic eye disease

Top 10 Tips for Healthier Eyes.


  1. Nayak AS, Berger WE, LaForce CF, Urdaneta ER, Patel MK, Franklin KB, Wu MM. Randomized, placebo-controlled study of cetirizine and loratadine in children with seasonal allergic rhinitis. Allergy Asthma Proc. 2017 May 1;38(3):222-230. doi: 10.2500/aap.2017.38.4050. PMID: 28441993.
  2. Nunes C, Ladeira S. Double-blind study of cetirizine and loratadine versus placebo in patients with allergic rhinitis. J Investig Allergol Clin Immunol. 2000 Jan-Feb;10(1):20-3. PMID: 10780795.
  3. Salmun LM, Gates D, Scharf M, Greiding L, Ramon F, Heithoff K. Loratadine versus cetirizine: assessment of somnolence and motivation during the workday. Clin Ther. 2000 May;22(5):573-82. doi: 10.1016/S0149-2918(00)80045-4. PMID: 10868555.
  4. Ramboer I, Bumtbacea R, Lazarescu D, Radu JR. Cetirizine and loratadine: a comparison using the ED50 in skin reactions. J Int Med Res. 2000 Mar-Apr;28(2):69-77. doi: 10.1177/147323000002800202. Erratum in: J Int Med Res 2000 Jul-Aug;28(4):197. PMID: 10898119.
  5. Asthma and Allergy Foundation of America. Allergy Facts.
  6. NHS UK. Cetirizine.
  7. Asthma and Allergy Foundation of America. Allergy Symptoms.

Top Products

Total Health


Glucose Control