Zyrtec vs Claritin: Which Allergy Med Works Better for You?

When it comes to Zyrtec, a brand name for cetirizine, a second-generation antihistamine used to treat seasonal allergies and hives. Also known as cetirizine, it’s one of the most common choices for quick relief from sneezing, runny nose, and itchy eyes. Many people reach for Claritin, a brand name for loratadine, another second-generation antihistamine designed to block histamine without causing drowsiness in most users. Also known as loratadine, it’s often chosen for all-day control with minimal side effects. Both are available over the counter, both promise relief from hay fever, and both are sold under generic names. But they’re not the same—and knowing the difference can save you from drowsiness, wasted money, or ineffective treatment.

Zyrtec usually kicks in faster—within an hour—while Claritin can take up to two hours to start working. If you’re caught off guard by sudden allergy flare-ups, Zyrtec gives you quicker comfort. But Zyrtec also causes drowsiness in about 14% of users, according to clinical studies. Claritin? Less than 1% of people feel sleepy. If you drive, work in a high-focus job, or just hate feeling sluggish, Claritin might be the safer pick. Zyrtec is slightly stronger for itching and hives, which is why some dermatologists recommend it for skin reactions. Claritin wins on consistency—it’s more predictable day after day, with fewer reports of rebound congestion or dry mouth.

Neither drug treats nasal congestion on its own. If you’re stuffed up, you’ll need a decongestant like pseudoephedrine, which is sold as Zyrtec-D or Claritin-D. But those versions can raise blood pressure and keep you awake. For simple sneezing and runny nose, stick to the plain versions. Also, Zyrtec is often recommended for kids as young as six months, while Claritin is approved for kids two and up. If you’re treating a toddler, check with your pediatrician.

Price-wise, both generics are cheap—often under $10 for a month’s supply. But insurance formularies sometimes favor one over the other, so your out-of-pocket cost might vary. And if you’re already taking other meds, watch for interactions. Zyrtec can interact with sedatives or alcohol more noticeably than Claritin. If you’re on thyroid meds, antidepressants, or even herbal supplements, talk to your doctor before switching.

What you’ll find below are real comparisons from people who’ve tried both, breakdowns of how they affect the body, and advice on when to stick with one or switch to the other. You’ll also see how these two stack up against other allergy treatments, what to do if they stop working, and how to avoid common mistakes that make them less effective. No fluff. Just what actually matters when your nose won’t stop running and your eyes won’t stop itching.