The Independent Pharmacy

Cetirizine Vs Loratadine For Hay Fever Relief

Scott McDougall
Scott McDougallMPharmDirector & Registered Manager

Reviewed on 7 May 2024

What is the difference between cetirizine vs loratadine?

While both can be effective hay fever treatments, cetirizine typically starts relieving allergy symptoms a bit faster than loratadine. However, loratadine is less likely to cause drowsiness as a side effect than cetirizine.

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The main distinctions lie in how quickly they start providing allergy relief, how long their effects last, and the different potential side effects they may cause.

Cetirizine (commonly known as Zirtek) and loratadine (Clarityn) are antihistamine medications that help control allergy symptoms like sneezing, runny nose, and itchy eyes. They work by blocking histamine, a chemical released by your body during an allergic reaction.

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We understand how frustrating allergy flare-ups can be. They can make everyday activities miserable and impact your quality of life. That’s why it’s important to know the pros and cons of different hay fever medications so you can find the right fit.

So, let’s dive into the key distinctions between these two popular hay fever tablets.

Key Takeaways

  • Cetirizine starts relieving allergy symptoms faster than loratadine but is more likely to cause drowsiness.
  • Loratadine takes a bit longer to work but is less sedating, making it better if you need to remain alert.
  • Both medications are effective for managing hay fever symptoms like runny noses, sneezing, itchy eyes and skin rashes from allergies.
  • Check with your doctor before using cetirizine or loratadine if you're pregnant, have kidney/liver issues, eye conditions, or regularly drink alcohol.

Cetirizine vs Loratadine at a Glance

Feature Cetirizine Loratadine
Onset of Action Starts working in 30-60 minutes Takes 1-3 hours to start working
Duration of Effect Lasts 24 hours Lasts 24 hours
Risk of Drowsiness Higher risk of causing drowsiness Lower risk of drowsiness
Dosing for Adults One 10mg tablet once daily One 10mg tablet once or twice daily
Common Side Effects Dry mouth, dizziness, headache, nausea Dry mouth, headache, fatigue, nausea
Long-Term Use Generally safe for long-term use, but check with your doctor Generally safe for long-term use, but check with your doctor
Interactions Can interact with medications like antidepressants, sedatives, muscle relaxants, and pain relievers Can interact with medications like antidepressants, sedatives, muscle relaxants, and pain relievers

Cetirizine vs Loratadine: Effectiveness


Cetirizine is an excellent allergy medication for relief from various annoying symptoms. It’s effective at:

  • Drying up runny noses and clearing nasal congestion caused by pollen, dust, pet dander, or other allergens in the air around you. No more constant dripping or stuffy noses!
  • Stopping the itchy, watery, red eyes that often come with hay fever and outdoor allergies. Cetirizine can soothe that uncomfortable itchiness.
  • Putting an end to uncontrollable sneezing fits and that overall miserable, lack of motivation feeling you get during bad allergy flare-ups.

The great thing about cetirizine is how quickly it starts working. According to the NHS, it begins providing symptom relief within just 30-60 minutes after taking it in many people. So if you need pretty fast allergy relief to get through your day, cetirizine could be the answer.


Loratadine is another excellent ally against allergy symptoms, especially:

  • Stuffy, runny noses that just won’t stop dripping thanks to seasonal or indoor allergens like pollen, dust mites, or pet dander. It helps dry up that nasal congestion. It can also help you find relief from hay fever when on holiday.
  • The itchy, watery, red eyes caused by hay fever. Loratadine can ease eye irritation.
  • Itchy skin rashes, hives, and other irritating skin reactions that can happen with allergies. It can help you calm the itchiness.

While it may take a bit longer than cetirizine to feel the effects (typically 1-3 hours), loratadine provides long-lasting relief. A single dose can keep your allergy symptoms controlled and comfortable for up to 24 hours. This could be convenient if you don’t want to re-dose frequently.

Cetirizine vs Loratadine: How Much Should You Take?


For adults, the NICE recommends the usual dose of the antihistamine cetirizine is one 10mg oral tablet taken just once daily. Since cetirizine has a slightly higher risk of causing somnolence or drowsiness as a side effect, it’s best to take your daily dose in the morning.

You’ll want to follow the dosage instructions on the cetirizine medication’s label or as directed by your healthcare provider. Even if your hay fever symptoms, like a runny nose or itchy eyes, don’t fully improve right away, don’t exceed the recommended single tablet dose. Give the antihistamine some time to build up in your system and provide more complete symptom relief.

If you’ve been taking the cetirizine oral tablet for a week or more without relief from your allergy symptoms, check back in with your doctor or allergist. It’s a good idea to consult with them. They may want to adjust your cetirizine dose or explore alternative hay fever treatment plans and medications.


The standard NICE guidance for adult dosing of the antihistamine loratadine is to take one 10mg oral tablet per day. Compared to cetirizine, loratadine has a lower risk of causing drowsiness as an unwanted side effect.

Just as with cetirizine, it’s very important not to exceed the recommended daily dose on the loratadine label or from your doctor unless they specifically advise a dosage increase. Taking more antihistamine tablets than directed doesn’t necessarily mean better hay fever control and could increase adverse effects.

Cetirizine vs Loratadine: Side Effects


According to the NHS, the most common side effect of cetirizine is feeling drowsy or sleepy during the day, which appears in more than 1 in 10 people. This drowsiness tends to be more pronounced with cetirizine compared to other antihistamine options.

Some adults (more than 1 in 100 people) may also experience:

  • Dry mouth
  • Slight dizziness
  • Mild headaches
  • Nausea

Serious side effects of cetirizine are very uncommon.

Overall, most people tolerate cetirizine well when taking the recommended dosages. But if you experience significant drowsiness, dizziness or any other concerning side effects, it’s important to let your doctor know immediately.


Loratadine tends to have a slightly better side effect profile compared to cetirizine for most people. The biggest advantage is significantly lower risk of causing excessive drowsiness or sleepiness during the day. Based on the NHS loratadine page, this happens in more than 1 in 100 people, which is less than with cetirizine.

Some of the more common side effects of loratadine can include:

  • Dry mouth
  • Headache
  • Fatigue
  • Nausea

Serious side effects are extremely unlikely when taking normal doses.

In general, loratadine is very well-tolerated, with a low incidence of side effects, especially drowsiness. This makes it an appealing antihistamine option for those who need to remain alert during the day.

Cetirizine vs Loratadine: Long-Term Use and Medication Interactions


For many adults, cetirizine is safe for daily long-term use to control allergy symptoms. However, it’s always best to check with your doctor first, especially if you have any other ongoing medical conditions.

Certain medications can potentially interact with cetirizine, increasing your risk of side effects or making hay fever relief less effective. For example, cetirizine should be used with caution if you also take medication for:

  • Depression or anxiety
  • Sedatives or sleep aids
  • Muscle relaxants
  • Pain medication

Your doctor or pharmacist can look at all your medications and supplements to ensure cetirizine won’t negatively interact.

To get a full picture, read through the list of cetirizine interactions from the NICE.


Like cetirizine, loratadine is generally considered safe for most people to use daily and long-term for allergy control. But you should still consult your doctor before taking loratadine regularly, especially if you have any underlying health issues.

Loratadine may interact with certain medications, increasing side effects or decreasing how well it relieves hay fever symptoms. You can see specific medications in NICE's guidance on loratadine interactions. Some drugs that could potentially interact include:

  • Antidepressants
  • Sedatives
  • Muscle relaxants
  • Pain relievers

It’s wise to have your doctor review all your current medications before starting a daily loratadine regimen for hay fever. They can ensure there are no risky drug interactions.

Cetirizine vs Loratadine: Cost and Availability

Cetirizine and loratadine cost the same at The Independent Pharmacy.

As for availability, both medications are very easy to find. They're sold over-the-counter at most drugstores, grocery stores, and major retailers in the allergy medication aisle.

And if you decide to find hay fever relief with The Independent Pharmacy, all you need to do is to fill in a self-assessment. That way, we can make sure that it's the right treatment for you. Then, you can enjoy quick delivery to your door with no need for a prescription.

Cetirizine vs Loratadine: Important Things to Know Before Using Them

Even though you can buy cetirizine and loratadine without a prescription, there are some important situations when you should talk to your doctor before taking either of these hay fever medications. The NHS guidance on antihistamines recommends you consult your doctor if you:

  • Are pregnant or breastfeeding - We still don’t know for sure if these antihistamines could potentially harm pregnant women, unborn babies, or nursing infants. Check with your doctor.
  • Have kidney or liver problems - Your kidneys and liver help filter out cetirizine. If they aren’t working well, you may need a lower dose. Loratadine is less affected.
  • Drink alcohol regularly - Alcohol can increase the drowsiness side effects from these medications to dangerous levels. It’s best not to drink while taking them.

Be sure to read all the warning labels and medication guides very carefully before using cetirizine or loratadine. Your doctor or pharmacist can give you personalised advice based on your specific health situation and any other medications you take. Don’t hesitate to ask them how to use these allergy meds safely and correctly.

How to Choose Between Cetirizine and Loratadine

At the end of the day, the “best” antihistamine for you depends on your specific allergic symptoms and personal preferences. Here are some key factors to consider:

  • Speed of Relief - Cetirizine may be preferred if you need faster hay fever symptom relief, as it kicks in quicker than loratadine.
  • Drowsiness Concern - Those who can’t have drowsiness interfering with their day may want to use loratadine, as it has a lower risk of causing that side effect.
  • Dosing Schedule - Cetirizine only needs to be taken once daily, while loratadine may require dosing twice daily for some people.
  • Type of Symptoms - Cetirizine may provide better relief for symptoms like runny nose and sneezing, while loratadine could be preferred more for itchy eyes and skin rashes.

We recommend discussing your allergy symptoms and lifestyle needs with your doctor or one of our pharmacists. They can guide you on whether cetirizine or loratadine might be the better antihistamine option.

Take the Next Step With The Independent Pharmacy

Tired of suffering through annoying hay fever and allergy symptoms? The Independent Pharmacy can help you find the best medication for relief.

Visit our website and take a quick online self-assessment about the allergy issues you’ve been dealing with. Our experts will then recommend if cetirizine, loratadine, or another antihistamine may work better for you. And if you'd like more information about the condition, read through our hay fever guides.

You can easily order the personalised hay fever treatment we suggest through our secure online pharmacy. You can also talk to our team if you need advice on how to prevent hay fever in the first place.

Don’t let seasonal allergies control your life – contact us today and let us help you start feeling better!


What is better cetirizine or loratadine?

There is no definitive “better” option between cetirizine and loratadine - they each have their own pros and cons. Cetirizine tends to start relieving allergy symptoms faster, usually within 30-60 minutes. However, it also has a higher risk of causing drowsiness as a side effect. Loratadine takes a bit longer to start working, around 1-3 hours but is less likely to make you feel sedated during the day.

Is loratadine more sedating than cetirizine?

No, quite the opposite. Loratadine is less sedating and has a much lower risk of causing drowsiness compared to cetirizine. This makes loratadine a preferable choice if you need to remain alert and focus on tasks or activities after taking an allergy medication.

Is cetirizine the strongest antihistamine?

No, cetirizine is not considered the strongest or most potent antihistamine available. While it is an effective hay fever medication, some other prescription antihistamines like fexofenadine (Allevia) are more powerful at blocking histamine’s effects on the body.

What is the strongest antihistamine?

Some of the strongest prescription antihistamine medications include fexofenadine (Allevia), desloratadine (Neoclarityn), and levocetirizine. These are more potent than over-the-counter options like cetirizine or loratadine for relieving allergy symptoms. And if you're curious, you can read more about the differences between desloratadine vs loratadine in our guide. However, stronger antihistamines also tend to have a higher risk of side effects.

Can I take cetirizine in the morning and loratadine at night?

Yes, you can safely take cetirizine and loratadine together by staggering them morning and night. Since they are different antihistamine medications, there is no issue with taking one in the morning and the other at night to maximise 24-hour allergy relief. Just be sure to follow the proper dosage amounts for each.

Which has less side effects, loratadine or cetirizine?

Loratadine generally has fewer side effects and is better tolerated compared to cetirizine, especially when it comes to sedation and drowsiness. The biggest advantage of loratadine is that it has a much lower risk of drowsy, tired feeling during the day, which cetirizine can sometimes cause.


NICE (2024). Cetirizine hydrochloride -

NHS (2021). Loratadine (Clarityn) -

NHS (2023). Antihistamines -

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