The best allergy medicine depends on your specific symptoms. For most people with seasonal allergies, a second-generation antihistamine taken once daily is the go-to starting point. If nasal congestion is your main complaint, a corticosteroid nasal spray is more effective than any pill. And for many allergy sufferers, combining the two works better than either one alone.
Second-Generation Antihistamines: The Standard Choice
Second-generation antihistamines are the most popular over-the-counter option for good reason. They relieve sneezing, itchy eyes, runny nose, and hives without causing significant drowsiness. Unlike older antihistamines, they don’t easily cross into the brain, which means you can take them during the day and function normally. They also last longer, so most people only need one dose per day.
The three you’ll see most often on pharmacy shelves are loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra). All three are effective, but they have slightly different profiles. Cetirizine tends to work the fastest and is sometimes considered the most potent of the three, but it’s also the most likely to cause mild drowsiness. Fexofenadine is the least sedating option, making it a better fit if you’re sensitive to that side effect. Loratadine falls somewhere in between. If one doesn’t seem to help after a week or two, it’s worth trying a different one, since people respond differently to each.
Nasal Steroid Sprays: Best for Congestion
If stuffiness and sinus pressure are your worst symptoms, an antihistamine pill alone may not be enough. Corticosteroid nasal sprays like fluticasone (Flonase) and mometasone (Nasonex) work by reducing inflammation directly in the nasal passages. They’re effective against congestion, sneezing, runny nose, and even itchy eyes, making them the broadest-acting single allergy treatment available over the counter.
The tradeoff is patience. Nasal steroid sprays take a few days to reach full effect, sometimes up to a week. They work best when used consistently throughout allergy season rather than on an as-needed basis. Side effects are generally minor: occasional nosebleeds, nasal irritation, or an unpleasant taste. Because they act locally rather than throughout the body, they carry far fewer systemic risks than steroid pills.
For people with moderate to severe seasonal allergies, pairing a daily nasal steroid spray with a second-generation antihistamine covers the widest range of symptoms.
Older Antihistamines: Effective but Sedating
First-generation antihistamines like diphenhydramine (Benadryl) and chlorpheniramine still work well for allergy symptoms, but they cross into the brain easily, which causes drowsiness, dry mouth, and blurred vision. They also wear off faster, requiring doses every four to six hours instead of once a day.
These older drugs pose particular risks for adults over 65. The American Geriatrics Society includes first-generation antihistamines on the Beers Criteria, a list of medications that carry elevated risks for older adults. The concerns include confusion, cognitive impairment, and increased fall risk. For younger adults, first-generation antihistamines can still be useful at bedtime when allergies are disrupting sleep, but they’re not a good choice for daytime use.
Decongestants: What Actually Works
When your nose is completely blocked, you might reach for a decongestant. Here’s what you should know: not all decongestants on the shelf are equally effective.
Phenylephrine is the decongestant found in most products sitting on open shelves (like the non-“D” versions of Sudafed). In 2023, an FDA advisory committee reviewed the evidence and concluded that oral phenylephrine, at the dose found in over-the-counter products, does not work as a nasal decongestant. The committee also found no evidence that a higher dose would be both safe and effective. It’s safe to take, but it likely won’t help your congestion.
Pseudoephedrine, by contrast, does work. It’s kept behind the pharmacy counter (not by prescription, but federal law requires you to show ID and sign for it). The purchase limits exist because pseudoephedrine can be used to manufacture illicit drugs, not because of safety concerns at normal doses. If you need an oral decongestant, pseudoephedrine is the one worth asking for.
Decongestant nasal sprays like oxymetazoline (Afrin) provide fast, powerful relief, but they should only be used for three days at a time. Longer use can cause rebound congestion, where your nose becomes more blocked than it was before you started.
Oral decongestants of any kind are not recommended for people with high blood pressure, heart disease, glaucoma, or an overactive thyroid. Side effects can include increased blood pressure, trouble sleeping, headache, and irritability.
Combination “D” Products
Products labeled with a “D” after the brand name (like Claritin-D or Allegra-D) combine an antihistamine with pseudoephedrine. These can be convenient if you need both, but the decongestant component adds cardiovascular risks. People with heart disease, high blood pressure, diabetes, or kidney problems should avoid them. If you’re healthy and dealing with both congestion and other allergy symptoms, a combination product kept behind the pharmacy counter can simplify your routine.
Eye Drops for Itchy Eyes
If itchy, watery eyes are a major part of your allergy picture, antihistamine eye drops can provide targeted relief that pills sometimes miss. Olopatadine (sold as Pataday) is available over the counter and requires just one drop per eye, once a day. It both blocks histamine and stabilizes the cells that release it, so it works preventively as well as reactively. Ketotifen (Zaditor) is another widely available option that works similarly.
Matching Medicine to Symptoms
Your best allergy medicine depends on what bothers you most:
- Sneezing, itching, and runny nose without much congestion: A second-generation antihistamine alone is usually sufficient.
- Congestion as the primary symptom: A corticosteroid nasal spray is the most effective single option.
- Multiple symptoms including congestion: A nasal steroid spray plus a second-generation antihistamine covers the most ground.
- Itchy, watery eyes: Add antihistamine eye drops to whatever else you’re using.
- Occasional or unpredictable flare-ups: Keep a second-generation antihistamine on hand for as-needed use, since these pills work within one to two hours.
Starting a nasal steroid spray a week or two before your allergy season typically begins gives it time to build up its anti-inflammatory effect. Antihistamine pills can be started the same day symptoms appear and still provide meaningful relief within hours.