Zyrtec (cetirizine) and Claritin (loratadine) are two popular over-the-counter medications used to treat allergies. When you’re sniffling and sneezing, you don’t want to spend extra time in your pharmacy aisle trying to decide which medicine will work best for you. Read on to learn more about these medications and which one may be better for you!

How do they work?

Both Zyrtec and Claritin work by blocking histamine, a natural substance that your body makes during an allergic reaction. Histamine is responsible for those pesky allergy symptoms like sneezing, runny nose, itchy or watery eyes, and itchy nose or throat. By binding to histamine receptors in your body, Zyrtec and Claritin prevent histamine from attaching to your cells and causing allergy symptoms.

Benadryl (diphenhydramine) is another antihistamine often used for allergy symptoms, but it’s notorious for making you sleepy. Zyrtec and Claritin are both considered non-sedating antihistamines, which means they are less likely than Benadryl to make you sleepy or affect your alertness. It is important to know that they may still cause some mild drowsiness; if you’re going to try Zyrtec or Claritin for allergies, it may be a good idea to take your first dose in the evening until you know how the medicine will affect you.

What type of allergic conditions do they treat?

Zyrtec and Claritin are both approved to treat seasonal allergies in anyone 2 years of age or older – they relieve symptoms like sneezing, runny or itchy nose, red or itchy skin, itchy or watery eyes, and postnasal drip. They are also approved to treat hives, which are red, itchy welts on your skin caused by an allergic reaction.

Although not approved by the FDA, Zyrtec has also been used off-label to treat skin-related symptoms of severe allergic reactions.

Which is more effective?

Both Zyrtec and Claritin are very effective at relieving allergy symptoms. Zyrtec may be slightly more effective in some patients, but also may cause more drowsiness than Claritin. If you drink alcohol or are taking any other medications that affect your CNS such as sedatives or anxiety medications, you should not take Zyrtec without talking to your doctor first.

Zyrtec has a very fast onset of action – it begins working in about an hour; Claritin may take up to 2-3 hours to provide relief from allergy symptoms. This difference probably won’t matter if you are taking the medication daily, as both medications work in your body for about 24 hours.

Both medications can be taken with or without food. They are safe to take every day or on an as-needed basis.

How much do they cost?

Zyrtec and Claritin both cost about the same. Because they are available over-the-counter, your insurance is not likely to pay for either of these medications. They are both available as generics, which are often less expensive than brand-name versions.

What are some common side effects?

Zyrtec and Claritin have similar side effects, which include:

• Dry mouth
• Headache
• Mild drowsiness
• Fatigue

TL;DR:

Zyrtec and Claritin are first-line over-the-counter treatments for allergies. Both are very effective at relieving symptoms like sneezing, runny nose, and itchy, watery eyes. Zyrtec may cause slightly more drowsiness than Claritin, but also begins working faster. If you need relief fast and drowsiness is not a concern, Zyrtec may be the better choice; if you have a big day ahead of you and need to stay alert, reach for the Claritin just to be safe.

References:

1. Kuna, P., Jurkiewicz, D., Czarnecka-Operacz, M. M., Pawliczak, R., Woroń, J., Moniuszko, M., & Emeryk, A. (2017). The role and choice criteria of antihistamines in allergy management–Expert opinion. Alergologia Polska-Polish Journal of Allergology, 4(1), 7-19.

2. Marion, DW. Cetirizine. In: UpToDate, Post, TW (Ed), UpToDate, Waltham, MA, 2021.

3. Marion, DW. Loratadine. In: UpToDate, Post, TW (Ed), UpToDate, Waltham, MA, 2021.