The most effective over-the-counter allergy medicines fall into three main categories: antihistamine pills, nasal steroid sprays, and allergy eye drops. For most people with seasonal or year-round allergies, a second-generation antihistamine like cetirizine or fexofenadine, combined with a nasal steroid spray like fluticasone if congestion is a problem, provides the best relief.
Antihistamine Pills: Your First Line of Defense
Second-generation antihistamines are the go-to starting point for allergies. They block histamine, the chemical your body releases during an allergic reaction, reducing sneezing, itching, runny nose, and watery eyes. The three most common options are cetirizine (Zyrtec), fexofenadine (Allegra), and loratadine (Claritin). All three are taken once daily and last a full 24 hours.
They’re not all equally effective, though. A large network analysis of randomized controlled trials found that loratadine ranked lowest among second-generation antihistamines for reducing every major allergy symptom, including nasal congestion, sneezing, itching, and eye symptoms. Cetirizine and its close relative levocetirizine consistently ranked higher, particularly for sneezing and nasal itching. If you’ve been taking loratadine and feel like it’s barely working, switching to cetirizine or fexofenadine is a reasonable move.
The tradeoff with cetirizine is drowsiness. While all second-generation antihistamines are marketed as “non-drowsy,” a large general-practice study found that cetirizine was about 3.5 times more likely to cause drowsiness than fexofenadine. Fewer than 1 in 140 patients reported drowsiness with any of these drugs, so the overall risk is low. But if you need to stay sharp during the day, fexofenadine is the least sedating option available.
Why You Should Skip Older Antihistamines
First-generation antihistamines like diphenhydramine (Benadryl) and chlorpheniramine are still widely sold, but they come with significant downsides. They cause pronounced drowsiness, wear off in four to six hours, and carry anticholinergic side effects: dry mouth, constipation, urinary retention, and blurred vision. For older adults, the risks are especially concerning. A study of hospitalized patients over 65 found that diphenhydramine use raised the risk of delirium symptoms by 70%, tripled the risk of inattention and altered consciousness, and was associated with longer hospital stays. These older drugs have their place for occasional nighttime use, but they’re a poor choice for daily allergy control.
Nasal Steroid Sprays for Congestion
If your main complaint is a stuffy, swollen nose, antihistamine pills alone often aren’t enough. Nasal corticosteroid sprays are the single most effective treatment for nasal allergy congestion. They reduce inflammation directly in your nasal passages, tackling stuffiness, drainage, and sneezing all at once. Three are available without a prescription: fluticasone propionate (Flonase), triamcinolone (Nasacort), and budesonide (Rhinocort).
All three work similarly well. The key thing to understand is that they don’t provide instant relief. You may notice some improvement within a day or two, but full effectiveness builds over one to two weeks of consistent daily use. That means starting your spray before allergy season hits, ideally two to four weeks ahead of time, gives you the best results. Most adults use two sprays in each nostril once a day. Aim the nozzle slightly away from the center wall of your nose to avoid irritation.
The Oral Decongestant Problem
Many allergy products on store shelves contain oral phenylephrine as a decongestant, often labeled with a “-D” suffix. Here’s the problem: it doesn’t work. An FDA advisory committee reviewed the scientific data and concluded that oral phenylephrine at its recommended dose is not effective as a nasal decongestant. The committee also found no evidence that a higher dose would be both safe and effective.
Pseudoephedrine (Sudafed) does work for congestion, but federal law requires it to be kept behind the pharmacy counter. You’ll need a photo ID and there are monthly purchase limits. It also isn’t safe for everyone. People with high blood pressure, heart disease, an overactive thyroid, glaucoma, diabetes, or an enlarged prostate should avoid it. Anyone taking MAO inhibitor antidepressants must not use it at all. For most allergy sufferers, a nasal steroid spray is a better long-term solution for congestion than any oral decongestant.
Allergy Eye Drops
If itchy, watery eyes are your biggest issue, OTC allergy eye drops can help where pills fall short. The two main options are ketotifen (Zaditor) and olopatadine (Pataday). Both block histamine directly in the eye and stabilize the cells that release it, providing dual-action relief. In a head-to-head study where patients tried both drops over four weeks, 81% preferred olopatadine, rating it more comfortable and more effective at reducing symptoms. Both are used once or twice daily depending on the formulation.
Cromolyn Sodium: A Gentler Alternative
Cromolyn sodium nasal spray (NasalCrom) takes a different approach. Instead of blocking histamine after it’s released, it prevents your immune cells from releasing it in the first place. It’s very well tolerated, with minimal side effects, making it a good option for people who are sensitive to other medications. The downside is frequency and patience: you need to spray it in each nostril three to four times a day, every four to six hours, and it can take one to two weeks to reach full effect. It works best when used consistently throughout your allergy season, not just when symptoms flare.
Allergy Medicine for Children
Most second-generation antihistamines come in liquid and chewable forms for kids. Cetirizine can be used in children as young as 6 months (at a low dose of 2.5 mL of syrup). Loratadine is approved for ages 2 and up. Fluticasone nasal spray can be used starting at age 4, with one spray per nostril daily for children under 12. Talk with your child’s doctor before giving any allergy medication to a child under 2.
Safety During Pregnancy and Breastfeeding
All antihistamines, both first- and second-generation, are considered safe during breastfeeding. Only minimal amounts pass into breast milk, not enough to affect an infant. During pregnancy, the evidence is also reassuring. First-generation antihistamines have the most data behind them and show no increased risk of birth defects. Second-generation options like cetirizine, loratadine, and fexofenadine have less data overall but have also not been linked to adverse pregnancy outcomes. A second-generation antihistamine is generally the better choice simply because it avoids the drowsiness and other side effects of older drugs.
Putting Together Your Allergy Plan
For mild allergies with mostly sneezing and itching, a daily second-generation antihistamine is usually enough. Cetirizine tends to be the most potent, fexofenadine the least sedating, and loratadine the weakest of the three. If nasal congestion is a major part of the picture, add a nasal steroid spray and give it at least a week to build up. For eye symptoms that don’t respond to oral antihistamines, add allergy eye drops. This layered approach, using targeted treatments for your specific symptoms, works better than relying on a single combination pill that may include ingredients you don’t need or that don’t work.