The best medicine for allergies depends on your main symptoms. For sneezing, itching, and a runny nose, a second-generation antihistamine like cetirizine (Zyrtec), loratadine (Claritin), or fexofenadine (Allegra) is the most common starting point. For persistent nasal congestion and inflammation, a corticosteroid nasal spray like fluticasone (Flonase) is often more effective. Many people benefit from using both together.
Antihistamines: The Go-To Option
Antihistamines work by blocking histamine, the chemical your immune system releases during an allergic reaction. Histamine is what triggers itchy eyes, sneezing, a runny nose, and hives. When an antihistamine locks onto the histamine receptor first, it keeps that receptor inactive so the reaction never fully takes off.
There are two generations of antihistamines, and the difference matters. First-generation options like diphenhydramine (Benadryl) cross into the brain easily, which is why they cause drowsiness. They also wear off in four to six hours, so you need multiple doses throughout the day. Second-generation antihistamines were specifically designed to stay out of the brain, making them far less sedating and effective for a full day on a single dose.
The three most widely used second-generation antihistamines are:
- Cetirizine (Zyrtec) starts working within one hour and maintains strong activity for about 19 hours. It’s the most potent of the three but slightly more likely to cause mild drowsiness in some people.
- Fexofenadine (Allegra) also kicks in within an hour but has a shorter window of peak effectiveness, closer to 8 to 9 hours at standard doses. It’s the least likely to cause any drowsiness at all.
- Loratadine (Claritin) takes a bit longer to reach full effect, typically around four hours, and lasts 24 hours. It sits in the middle for sedation risk.
All three are available over the counter and safe for daily use during allergy season. If one doesn’t seem to work well for you, switching to another is reasonable since people respond differently to each.
Nasal Corticosteroid Sprays
For nasal congestion, postnasal drip, and sinus pressure, corticosteroid sprays are more effective than antihistamines alone. They work by reducing the flood of inflammatory cells into the nasal lining, which shrinks swollen tissue and opens your airways. Unlike antihistamines, which mainly block one chemical, these sprays target the broader inflammatory process.
Fluticasone propionate (Flonase) and triamcinolone acetonide (Nasacort) are the two most common over-the-counter options. Prescription alternatives include budesonide (Rhinocort), mometasone (Nasonex), and ciclesonide (Omnaris). They all work similarly. The key thing to know is that nasal steroid sprays need consistent daily use for several days before they reach full effect. They’re not instant relief like a decongestant, but they control symptoms much better over time.
Decongestants: Use With Caution
Nasal decongestant sprays like oxymetazoline (Afrin) can clear a stuffed nose within minutes. The catch is that you should not use them for more than three consecutive days. After about three days, these sprays can trigger rebound congestion, a condition called rhinitis medicamentosa, where your nose becomes more blocked than it was before you started using the spray. This creates a cycle that can be difficult to break.
Oral decongestants like pseudoephedrine (Sudafed) don’t cause rebound congestion, but they raise blood pressure and heart rate. They’re fine for short-term use during a bad flare but aren’t ideal as a daily allergy medication.
Cromolyn Sodium: A Preventive Option
Cromolyn sodium (NasalCrom) is an over-the-counter nasal spray that works differently from antihistamines and steroids. It stabilizes mast cells, the immune cells that release histamine in the first place. By keeping those cells from dumping their contents, it prevents sneezing, itching, and a runny or stuffy nose before they start.
The tradeoff is that cromolyn works best when you start using it before allergy season hits or before you know you’ll be exposed to a trigger. It also needs to be used multiple times a day, which makes it less convenient than a once-daily antihistamine. But it has an excellent safety profile, which makes it a good choice for people who want to avoid other medications.
Montelukast: A Prescription Alternative
Montelukast (Singulair) is a prescription pill that blocks leukotrienes, another group of chemicals involved in allergic inflammation. It’s approved for seasonal and year-round allergic rhinitis in adults and children as young as six months for perennial symptoms. It can be helpful when antihistamines and nasal sprays aren’t doing enough on their own, and it’s particularly useful for people who also have asthma since it treats both conditions.
However, montelukast carries a boxed warning from the FDA for potential mental health side effects, including mood changes, anxiety, depression, sleep disturbances, and in rare cases, suicidal thoughts. Because of this warning, current guidelines recommend it only for people who haven’t responded adequately to other allergy treatments.
Allergy Immunotherapy
If you’ve tried multiple medications and still struggle with allergies, immunotherapy is the only treatment that can change how your immune system responds to allergens over the long term. It works by gradually exposing you to increasing amounts of the substance you’re allergic to until your body stops overreacting.
There are two forms. Allergy shots involve an initial phase of frequent injections with increasing doses, followed by monthly maintenance injections. Sublingual immunotherapy uses a tablet or liquid placed under the tongue daily. Both approaches are similarly effective at controlling symptoms, and both provide lasting improvement that persists even after treatment ends. The full course typically takes three to five years, which is a significant commitment, but it’s the closest thing to a long-term fix.
Allergy Medicine for Children
Most second-generation antihistamines are available in liquid and chewable forms for children. Cetirizine (Zyrtec) is approved for infants as young as six months. Loratadine (Claritin) and fexofenadine (Allegra) are approved starting at age two. All three come as syrups dosed by age, making them easy to administer.
Diphenhydramine (Benadryl) should not be given to children under two and is dosed by weight rather than age for older kids. Because it causes drowsiness and must be given every six hours, a second-generation option is usually the better daily choice. Benadryl still has a role for acute allergic reactions when fast-acting relief matters, but it’s not ideal for routine use.
Newer Treatment for Food Allergies
In February 2024, the FDA approved omalizumab (Xolair) as the first medication to reduce allergic reactions to multiple foods after accidental exposure. Xolair is a biologic injection that binds to the antibody responsible for triggering allergic reactions, preventing it from activating the immune cascade. It’s approved for adults and children one year and older with confirmed food allergies.
In clinical trials, 68% of people receiving Xolair tolerated a dose of peanut protein without moderate to severe symptoms, compared to just 6% on placebo. Results were similarly strong for milk (66% vs. 11%), egg (67% vs. 0%), and cashew (42% vs. 3%). Xolair is not a cure and doesn’t replace the need to avoid allergens. It’s a safety net that raises the threshold for a reaction if accidental exposure happens. It does carry a boxed warning for anaphylaxis as a possible side effect of the injection itself, so it’s administered under medical supervision.
Combining Medications
For moderate to severe allergies, a single medication often isn’t enough. The most effective over-the-counter combination for most people is a daily second-generation antihistamine plus a daily nasal corticosteroid spray. The antihistamine handles itching, sneezing, and eye symptoms, while the steroid spray targets nasal congestion and inflammation. These two classes work through completely different mechanisms, so they complement rather than duplicate each other. Adding antihistamine eye drops like ketotifen (Zaditor) can help if itchy, watery eyes are your worst symptom. The goal is to match your medication strategy to whichever symptoms bother you most.