Allergies are treated with a combination of allergen avoidance, medications that control symptoms, and in some cases, long-term therapies that retrain the immune system to stop overreacting. The right approach depends on the type and severity of your allergy, but most people start with over-the-counter options and escalate from there if symptoms persist.
Antihistamines
Antihistamines are the most widely used allergy medication. They work by stabilizing histamine receptors in your body so they stop sending the signals that cause sneezing, itching, hives, and a runny nose. There are two generations of these drugs, and the distinction matters.
First-generation antihistamines (like diphenhydramine, sold as Benadryl) cross into the brain and interfere with alertness. They cause drowsiness, slow reaction times, and impair learning and concentration. They work, but they come with real tradeoffs if you need to function during the day. Second-generation antihistamines (like cetirizine, loratadine, and fexofenadine) were designed to stay out of the brain. They’re effective with far less sedation and have well-documented safety records for daily use. For most people with seasonal or year-round allergies, a second-generation antihistamine taken daily is the simplest starting point.
Nasal Corticosteroid Sprays
For moderate to severe nasal allergies, steroid nasal sprays are considered the most effective treatment available. They reduce inflammation directly in the nasal lining, which addresses congestion, sneezing, and postnasal drip more comprehensively than antihistamines alone. Several are available over the counter, including fluticasone (Flonase) and triamcinolone (Nasacort).
The key thing to understand about nasal sprays is timing. You’ll start noticing some relief within 3 to 12 hours, but the full effect takes about two weeks of consistent daily use. This means they’re not something you grab when symptoms hit. They work best when you start using them before allergy season begins and keep using them throughout. Many people give up too early because they expect instant results.
Decongestants
Decongestants shrink swollen blood vessels in the nasal passages, which opens up airflow. Nasal spray decongestants (like oxymetazoline) work quickly but should only be used for a few days at a time, since longer use causes rebound congestion that’s worse than the original problem.
Oral decongestants deserve a closer look. The FDA has proposed removing oral phenylephrine, found in many popular cold and allergy products, from the approved list of over-the-counter decongestants. An advisory committee unanimously concluded that oral phenylephrine does not work as a nasal decongestant at recommended doses. This ruling is based on effectiveness concerns, not safety. Products containing it are still on shelves for now, but if you’ve been taking an oral allergy or cold medication and feel like the decongestant isn’t doing anything, this may be why. The nasal spray form of phenylephrine is not affected by this proposal. Pseudoephedrine (sold behind the pharmacy counter) remains effective but can raise blood pressure and cause insomnia.
Leukotriene Modifiers
Montelukast (originally sold as Singulair) blocks a different chemical pathway involved in allergic inflammation. It’s approved for seasonal outdoor allergies in patients 2 and older and year-round indoor allergies in those 6 months and older. However, the FDA added its most serious warning label to this drug due to reports of mood changes, agitation, sleep disturbances, and suicidal thoughts. Because of these risks, the FDA now recommends montelukast only be used for allergies when other treatments haven’t worked or aren’t tolerated. It remains a more common choice for asthma, where its benefits are harder to replace.
Allergen Immunotherapy
If medications manage your symptoms but don’t give you the quality of life you want, immunotherapy is the only treatment that changes how your immune system responds to allergens over the long term. It works by exposing you to gradually increasing amounts of the substance you’re allergic to until your body learns to tolerate it.
There are two forms. Subcutaneous immunotherapy (allergy shots) involves regular injections at a doctor’s office, typically weekly during a buildup phase and then monthly for maintenance, over a course of three to five years. Sublingual immunotherapy (allergy tablets or drops placed under the tongue) can be done at home after the first dose is given under medical supervision. Sublingual tablets are currently available for grass pollen, ragweed, and dust mites. Both approaches can provide lasting relief that persists even after treatment ends, which no medication can do.
Treating Food Allergies
Food allergies have historically had no treatment beyond strict avoidance and carrying emergency medication. That’s starting to change.
For peanut allergy specifically, an oral immunotherapy product is available for patients ages 1 through 17. It works through a carefully supervised dose escalation process, starting with tiny amounts of peanut protein (as low as 0.5 milligrams) and gradually increasing over months until the patient reaches a daily maintenance dose of 300 milligrams. That maintenance dose must be taken every day to keep the protection in place. The goal isn’t to let someone eat peanut butter freely; it’s to raise the threshold so that an accidental exposure to a small amount doesn’t trigger a severe reaction.
In February 2024, the FDA approved the first medication designed to reduce allergic reactions to multiple foods after accidental exposure. This injectable biologic, originally developed for severe asthma, works by blocking the antibody (IgE) that drives allergic reactions. In clinical trials, after 16 to 20 weeks of treatment, 68% of patients on the drug could tolerate the equivalent of about 2.5 peanuts without moderate to severe symptoms, compared to just 6% on placebo. Results were similar for other foods: 67% could tolerate egg protein (versus 0% on placebo), 66% could tolerate milk (versus 11%), and 42% could tolerate cashew (versus 3%). This treatment is meant for ongoing use to reduce the risk of reactions from accidental exposure. It is not a replacement for epinephrine in an emergency.
Emergency Treatment for Severe Reactions
Anaphylaxis, a severe whole-body allergic reaction, requires immediate treatment with epinephrine. Auto-injectors deliver a pre-measured dose into the outer thigh and can be used through clothing. The standard adult dose is 0.3 mg for anyone weighing 30 kg (about 66 pounds) or more. A junior dose of 0.15 mg is used for children between 15 and 30 kg (roughly 33 to 66 pounds).
If you or your child has a known risk for anaphylaxis from foods, insect stings, or any other trigger, carrying two auto-injectors is standard practice. Severe reactions can sometimes require a second injection, though using more than two doses without medical supervision is not recommended. After using epinephrine, you still need emergency medical care, since symptoms can return as the medication wears off.
Reducing Allergen Exposure at Home
No treatment works as well when you’re constantly re-exposing yourself to the trigger. For indoor allergens like dust mites, pet dander, and mold, practical environmental changes make a measurable difference. Encasing mattresses and pillows in allergen-proof covers, washing bedding weekly in hot water, and keeping indoor humidity below 50% all reduce dust mite levels. For pet allergies, keeping animals out of the bedroom and off upholstered furniture limits exposure in the spaces where you spend the most time.
HEPA air filters can capture airborne particles like pet dander, and studies show some reduction in cat and dog allergen levels with their use. That said, most clinical studies have not conclusively proven that HEPA filters alone reduce the need for allergy medication. They’re best used as one part of a broader strategy rather than a standalone solution. For pollen allergies, keeping windows closed during high-count days, showering after spending time outdoors, and running air conditioning with a clean filter are simple steps that meaningfully reduce how much pollen you breathe while sleeping.