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Allegra vs. Allegra-D — What's the Difference?

By Tayyaba Rehman — Published on January 20, 2024
Allegra is an antihistamine used to treat allergy symptoms. Allegra-D combines this antihistamine with a decongestant to also treat nasal congestion.
Allegra vs. Allegra-D — What's the Difference?

Difference Between Allegra and Allegra-D


Key Differences

Allegra, whose active ingredient is fexofenadine, is used primarily to treat seasonal allergy symptoms like sneezing, itching, and watery eyes. Allegra-D contains fexofenadine and pseudoephedrine, the latter being a decongestant that relieves sinus pressure and nasal congestion.
Allegra works by blocking histamine, a substance in the body that causes allergic symptoms. Allegra-D not only blocks histamine but also constricts blood vessels in the nasal passages to reduce swelling and congestion.
Allegra is often preferred for general allergy relief without the need for nasal decongestion. Allegra-D is more suitable for those experiencing both allergies and nasal congestion, such as with sinusitis or the common cold.
Allegra has minimal side effects, typically not causing drowsiness. Allegra-D, due to its pseudoephedrine content, may cause insomnia, nervousness, or dizziness in some people.
While Allegra can be purchased over the counter without restrictions, Allegra-D is often kept behind the pharmacy counter due to the pseudoephedrine, which can be misused for illicit drug manufacturing.

Comparison Chart

Active Ingredient

Fexofenadine and pseudoephedrine

Primary Use

Treats allergy symptoms
Treats allergy symptoms and nasal congestion

Mechanism of Action

Antihistamine and decongestant

Common Side Effects

Minimal, non-drowsy
May cause insomnia, nervousness, or dizziness


Over the counter
Behind the counter due to pseudoephedrine content

Compare with Definitions


Over-the-counter medication for allergy relief.
I bought Allegra at the pharmacy without a prescription.


Combines antihistamine with decongestant for allergies and congestion.
Allegra-D was effective for his sinus pressure and allergies.


A non-sedating antihistamine choice.
Allegra is great as it doesn't interfere with my daily activities.


Contains pseudoephedrine for nasal decongestion.
The pseudoephedrine in Allegra-D cleared her nasal congestion.


An antihistamine for treating seasonal allergies.
He took Allegra for his springtime pollen allergies.


May cause side effects like insomnia or dizziness.
He experienced some restlessness with Allegra-D.


Suitable for daily use with minimal side effects.
She preferred Allegra because it didn't make her drowsy.


Ideal for comprehensive allergy and cold symptoms.
She took Allegra-D during the cold season for dual relief.


Contains fexofenadine, effective against allergic reactions.
Allegra relieved her itching and sneezing quickly.


Available from the pharmacy counter due to pseudoephedrine.
I asked the pharmacist for Allegra-D for my severe sinus congestion.

Common Curiosities

Can Allegra treat skin allergies?

Yes, Allegra can help relieve symptoms of skin allergies.

Can children take Allegra?

Yes, there are child-specific formulations of Allegra.

Is Allegra effective for pet allergies?

Yes, Allegra can relieve symptoms of pet allergies.

Is Allegra-D good for sinus infections?

Yes, Allegra-D can relieve congestion associated with sinus infections.

Does Allegra-D increase blood pressure?

Pseudoephedrine in Allegra-D may increase blood pressure in some individuals.

Does Allegra cause drowsiness?

Allegra is generally non-drowsy.

Can I take Allegra daily?

Yes, Allegra can be taken daily for continuous allergy relief.

Is Allegra-D addictive?

No, but the pseudoephedrine in it can be misused; hence, its sale is regulated.

Who shouldn't take Allegra-D?

People with high blood pressure, heart disease, or thyroid problems should consult a doctor before taking Allegra-D.

Can I buy Allegra-D without a prescription?

Allegra-D is available without a prescription but is kept behind the pharmacy counter.

How quickly does Allegra work?

Allegra typically starts working within an hour.

Can pregnant women take Allegra?

Pregnant women should consult their doctor before taking Allegra.

Is it safe to drive after taking Allegra-D?

If experiencing dizziness or nervousness, avoid driving or operating heavy machinery.

Can I take Allegra-D with other medications?

Consult a doctor before combining Allegra-D with other medications.

Can Allegra help with food allergies?

Allegra can relieve symptoms, but it is not a treatment for food allergies.

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Author Spotlight

Written by
Tayyaba Rehman
Tayyaba Rehman is a distinguished writer, currently serving as a primary contributor to As a researcher in semantics and etymology, Tayyaba's passion for the complexity of languages and their distinctions has found a perfect home on the platform. Tayyaba delves into the intricacies of language, distinguishing between commonly confused words and phrases, thereby providing clarity for readers worldwide.

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