Best Allergy Medicine: Zyrtec vs Claritin vs Allegra vs Flonase Compared

Written by Cherlie Joseph, MSN, FNP-BC · Medically reviewed by Naurah Gaspard, DNP, FNP-C, FNP-BC · Updated November 2026

For most adults with a stuffy nose plus sneezing, a daily steroid nasal spray like Flonase or Nasacort works best overall. For quick relief of itching, sneezing and runny nose, a non-drowsy antihistamine is a good choice: Allegra and Claritin are least likely to make you sleepy, while Zyrtec and Xyzal may work a bit faster for some people but cause drowsiness more often.

Quick answer: match the medicine to your symptoms

• Mostly stuffy nose and postnasal drip: a steroid nasal spray, used every day.
• Itchy, sneezy, runny nose that comes and goes: a non-drowsy antihistamine pill on the days you need it.
• Itchy, watery eyes: an antihistamine eye drop (ketotifen or olopatadine), alone or with the options above.
• Everything at once and nothing is working: many people combine a steroid spray with an antihistamine. That is a good time to check in with a provider.

Allergy specialists (AAAAI) describe steroid nasal sprays as the most effective single medicine for nasal allergy symptoms.

Zyrtec vs Claritin vs Allegra vs Xyzal vs Flonase compared

Medicine	Type	Drowsiness	Good to know
Zyrtec (cetirizine)	Antihistamine pill	More likely than Claritin or Allegra	Often works within an hour or so. Rare severe itching reported after stopping long-term daily use (FDA, 2025).
Xyzal (levocetirizine)	Antihistamine pill	More likely than Claritin or Allegra	Closely related to cetirizine, with the same FDA itching warning. Label suggests taking in the evening.
Claritin (loratadine)	Antihistamine pill	Least likely	Can be slower to start and may feel milder for some people.
Allegra (fexofenadine)	Antihistamine pill	Least likely	Label says not to take it with fruit juice, which lowers how much is absorbed. Take with water.
Flonase, Nasacort, Rhinocort (steroid sprays)	Nasal spray	No	Best for congestion. Some relief in the first day, but full benefit takes several days of daily use.

All of these are available over the counter, and the generics contain the same active ingredient as the brands. Prices change often, so compare store brands and use a discount tool like GoodRx before you buy.

Decongestants and older antihistamines

Diphenhydramine (Benadryl) and other older antihistamines work, but they cause drowsiness, dry mouth and slowed reaction time, and they are a poor fit for daily use, especially in older adults.

Pseudoephedrine (sold behind the pharmacy counter) can relieve congestion for a few days but can raise blood pressure and heart rate and keep you awake. Oral phenylephrine, found in many shelf products, has been found by the FDA not to work as a decongestant when taken by mouth, and the agency has proposed removing it as an OTC decongestant ingredient.

Oxymetazoline sprays (Afrin) work fast but should not be used more than 3 days in a row, or congestion can rebound and get worse.

Safety notes before you choose

• Check with a provider before using decongestants if you have high blood pressure, heart disease, glaucoma, thyroid disease, an enlarged prostate or trouble urinating.
• If you are pregnant or breastfeeding, ask before starting any allergy medicine.
• Read labels on cold and sinus combination products so you do not double up on the same ingredient.
• Avoid alcohol and driving until you know how an antihistamine affects you.
• If you plan to take cetirizine or levocetirizine daily for months, talk with a provider first about the FDA's warning on itching after stopping.

When OTC medicine isn't enough

If you've used a steroid spray correctly for a couple of weeks and still feel miserable, other options a provider may review include an antihistamine nasal spray (azelastine is now available OTC), a prescription combination spray, or referral to an allergist for testing and immunotherapy. Montelukast (Singulair) has an FDA boxed warning about mood and behavior changes and is usually reserved for people who cannot use other options. New or worsening symptoms are best reviewed at a visit.

Frequently asked questions

Which allergy medicine is strongest?

For nasal congestion, steroid nasal sprays are the most effective single option. Among pills, cetirizine and levocetirizine may feel stronger for some people but cause drowsiness more often than loratadine or fexofenadine. The best choice depends on your symptoms and other health conditions.

Can I take Zyrtec and Flonase together?

For most healthy adults, yes. A non-drowsy antihistamine and a steroid nasal spray work in different ways and are commonly used together. Check with a provider or pharmacist if you take other medicines or have chronic health conditions.

Is it bad to take allergy medicine every day?

Steroid nasal sprays are designed for daily use during your season. Daily antihistamines are generally safe for many adults, but the FDA has warned about rare severe itching after stopping long-term cetirizine or levocetirizine, so it's worth discussing long-term plans with a provider.

Sources

• AAAAI: Hay Fever Medications
• FDA: Warning about rare, severe itching after stopping long-term cetirizine or levocetirizine (May 2025)
• FDA: Key information about oral phenylephrine

Keep reading

• Steroid nasal sprays: Flonase, Nasacort and more
• Seasonal allergies in Florida
• Montelukast (Singulair): what to know
• Eye drops guide
• Browse all conditions and treatments A to Z

This article is for general education and is not a substitute for medical advice. Treatment, including any prescription, is decided by a licensed provider after reviewing your health history. OurTopClinic is not for emergencies; if you have a medical emergency, call 911. OurTopClinic serves adults located in Florida, New Mexico, Oregon and Washington. Learn more at ourtopclinic.com.