Claritin, Zyrtec Or Allegra: What's The Difference?

Have you ever headed out your door to enjoy the great outdoors only to find yourself sneezing constantly and experiencing a stuffy or runny nose, itchy eyes, or hives? But when you head to your local pharmacy or grocery store to pick up an over-the-counter antihistamine to nix the nasty hay fever symptoms, you end up staring at the multitude of options in sheer befuddlement, wondering what the difference is? 

You may have seen the tacky montage commercials for Claritin (loratadine), Zyrtec (cetirizine), and Allegra (fexofenadine), as they seem to be three of the most popular and widely available allergy medicines. According to Verywell Health, each of these options has been available to the public without the need for a prescription for many years. However, although they are all three antihistamines, they do have differences that are worth paying attention to. 

"Depending on the allergic condition being treated, the age of the person, as well as other underlying issues (such as pregnancy), the best choice of antihistamine might be different," Verywell Health says. Let's get into more of the differences between these allergy medicines.

As we mentioned, Claritin, Zyrtec, and Allegra are all classified as antihistamines. As their name suggests, antihistamines work by blocking the presence of histamine in your body. According to the NHS, histamine gets released when your body senses a dangerous substance, and the stuff effectively begins attacking it. But sometimes, the supposed threat is actually just pollen, dust, or an animal's fur, yet your body releases histamine anyways. In that case, antihistamines can either prevent the reaction from taking place or help relieve symptoms once they've started.

In addition to hay fever (which is also called allergic rhinitis, per Verywell Health), antihistamines also help relieve the symptoms of hives, conjunctivitis, and reactions to insects bites or stings (via NHS). According to the NHS, they come in a variety of forms, including "tablets, capsules, liquids, syrups, creams, lotions, gels, eyedrops and nasal sprays." The NHS also says that there isn't sufficient evidence to show that any one antihistamine brand is better than another — rather, it depends on personal preference, and you have to find out which type works best for you and your body.

Claritin, Zyrtec, and Allegra have many similarities, but they also have some key differences. For example, all three are safe for pregnant and breastfeeding women but may also cause side effects such as blurred vision, dry mouth, drowsiness, dizziness, confusion, and nausea (via Verywell Health). However, the severity of these side effects differs. Verywell Health notes that while Zyrtec "causes sedation in approximately one in six people who take the medication," Claritin is "minimally sedating (makes only a small number of people sleepy)" and Allegra is "completely non-sedating (doesn't make people sleepy)."

Another difference involves how long it takes for each antihistamine to begin working. "Zyrtec and Allegra work quickly for the treatment of allergic rhinitis and hives, typically within less than an hour," the site says. "On the other hand, studies show that Claritin takes many hours to start working." Zyrtec also appears to work better for treating hives than its counterparts.

Lastly, the dosage is slightly different, which also makes a difference in the age at which you can take each medicine. Per VerWell Health, both Claritin and Zyrtec have a recommended dose of 10mg once a day for children over the age of 6. Allegra, on the other hand, can be taken by children as young as 6 months old, but two lower doses are required for those under the age of 12. Hopefully, one of these options will work well for you and your body!