Skip to main content

Loratadine (Clarityn)

On this page

  1. About loratadine
  2. Key facts
  3. Who can and cannot take loratadine
  4. How and when to take loratadine
  5. Side effects
  6. How to cope with side effects of loratadine
  7. Pregnancy and breastfeeding
  8. Cautions with other medicines
  9. Common questions about loratadine

1. About loratadine

Loratadine is an antihistamine medicine that helps with the symptoms of allergies. It's used to treat:

Loratadine is known as a non-drowsy antihistamine. It's much less likely to make you feel sleepy than some other antihistamines.

Loratadine is available on prescription. You can also buy it from pharmacies and supermarkets.

It comes as tablets or as a liquid that you swallow.

2. Key facts

  • You'll usually take loratadine once a day.
  • Loratadine is classed as a non-drowsy antihistamine, but some people still find it makes them feel slightly sleepy.
  • Children may have a headache and feel tired or nervous after taking loratadine.
  • It's best not to drink alcohol while you're taking loratadine as it can make you feel sleepy.

3. Who can and cannot take loratadine

Adults and children aged 2 years and older can take loratadine.

Loratadine is not suitable for some people. To make sure it's safe for you, tell your doctor or pharmacist before taking loratadine if you:

  • have ever had an allergy to loratadine or any other medicines
  • have severe liver failure
  • have an allergy to food additives
  • have epilepsy or another illness that puts you at risk of seizures or fits
  • are due to have an allergy test – taking loratadine may affect the results, so you might need to stop taking it a few days before the test

4. How and when to take loratadine

If you or your child have been prescribed loratadine, follow your doctor's instructions about how and when to take it.

If you've bought loratadine from a pharmacy or shop, follow the instructions that come with the packet.


Loratadine comes as 10mg tablets and as a liquid medicine (labelled either 5mg/5ml or 1mg/1ml).

The usual dose in adults is 10mg once a day.

Doses are usually lower for people with liver problems.

For children, your doctor will use your child's weight or age to work out the right dose. Children aged between 6 and 12 years can only take loratadine tablets if they weigh more than 30kg. Give children loratadine liquid instead of tablets if they are under 6 or weigh 30kg or less.

How to take it

Loratadine comes as 2 different types of tablet: ordinary and melt-in-the-mouth tablets.

Swallow ordinary loratadine tablets with a drink of water, milk or juice. If the tablet has a score line across the middle, you can break it in half if you find it hard to swallow it whole. Do not chew it.

Melt-in-the-mouth tablets dissolve instantly on your tongue without needing a drink. Be careful not to crush them when you take them out of the packet.

You can take loratadine with or without food.

Loratadine liquid may be easier for children to take than tablets. The medicine will come with a plastic syringe or spoon to help you measure out the right dose. If you do not have a syringe or spoon, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.

When to take it

You may only need to take loratadine on a day when you have symptoms, for instance if you've been exposed to a trigger such as animal hair. Or you may need to take it regularly to prevent symptoms, such as hay fever during spring and summer.

Try to take loratadine at about the same time every day. Choose a time that is easy to remember.

What if I forget to take it?

If you forget to take a dose, take it as soon as you remember, unless it's nearly time for your next dose. In this case, skip the missed dose and take your next dose at the usual time.

Do not take 2 doses to make up for a forgotten dose.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

What if I take too much?

Loratadine is generally very safe. If you or your child take too much, it is unlikely to harm you.

Urgent advice: Contact 111 for advice if:

You've taken more than your usual dose of loratadine and:

  • you get a headache, have a fast heartbeat or feel sleepy
  • you're concerned

Go to or call 111

Call 111 if you're asking about a child under the age of 5 years.

5. Side effects

Like all medicines, loratadine can cause side effects, although not everyone gets them.

Common side effects

The most common side effect of loratadine is feeling sleepy. This happens in more than 1 in 100 people.

Side effects in children may include:

  • headaches
  • feeling tired or nervous

Serious allergic reaction

In rare cases, loratadine may cause a serious allergic reaction (anaphylaxis).

Immediate action required: Call 999 now if:
  • your lips, mouth, throat or tongue suddenly become swollen
  • you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
  • your throat feels tight or you're struggling to swallow
  • your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
  • you suddenly become very confused, drowsy or dizzy
  • someone faints and cannot be woken up
  • a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)

You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.

These can be signs of a serious allergic reaction and may need immediate treatment in hospital.

These are not all the side effects of loratadine. For a full list see the leaflet inside your medicines packet.


You can report any suspected side effect using the Yellow Card safety scheme.

Visit Yellow Card for further information.

6. How to cope with side effects of loratadine

What to do about:

  • feeling sleepy – try a different non-drowsy antihistamine. If this does not help, talk to your doctor.
  • headaches – make sure you rest and drink plenty of fluids. Ask your pharmacist to recommend a painkiller. Headaches should normally go away after the first week of taking loratadine. Talk to your doctor if they last longer than a week or are severe.
  • feeling tired or nervous – talk to your doctor or pharmacist if these side effects do not go away. They may be able to offer you a different antihistamine.

7. Pregnancy and breastfeeding

Loratadine and pregnancy

Loratadine can be taken in pregnancy. There is no good evidence that it can harm your baby.

Loratadine and breastfeeding

If your doctor or health visitor says your baby is healthy, you can take loratadine while breastfeeding.

There is some information available which shows that only tiny amounts get into breast milk. It has been used for many years in breastfeeding women without side effects in their babies.

If your baby is not feeding as well as usual, or seems unusually sleepy, or if you have any other concerns about your baby, talk to your doctor, pharmacist, health visitor or midwife.

Find out more about how loratadine can affect you and your baby during pregnancy on the Best Use of Medicines in Pregnancy (BUMPS) website.

8. Cautions with other medicines

Some medicines affect how loratadine works or can increase the chances of you having side effects.

Tell your doctor if you're taking:

  • amiodarone, a medicine used to treat an irregular heartbeat
  • cimetidine, an indigestion medicine
  • erythromycin, an antibiotic
  • ketoconazole, a medicine to treat fungal infections
  • any medicine that makes you feel sleepy, gives you a dry mouth or makes it difficult for you to pee – taking loratadine might make these side effects worse

Mixing loratadine with herbal remedies and supplements

There's very little information about taking herbal remedies and supplements with loratadine. But there might be a problem with some of them, especially ones that cause sleepiness or a dry mouth, or make it difficult to pee.

Ask your pharmacist for advice.

Important: Medicine safety

Tell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements.

9. Common questions about loratadine

How does loratadine work?

Loratadine is a type of medicine called an antihistamine.

When you come into contact with something you have an allergy to, such as pollen, animal hair or fur, house dust or insect bites, your body produces a chemical called histamine.

Usually, histamine is a useful substance but in an allergic reaction it causes unpleasant symptoms including itchy, watery eyes, running or blocked nose, sneezing and skin rashes.

Loratadine blocks the effects of histamine and so reduces these symptoms.

Loratadine is a non-drowsy antihistamine, so it does not make you feel as sleepy as other medicines like it.

When will I feel better?

You should start to feel better within an hour.

How long should I take loratadine for?

It depends on why you're taking it.

You may only need to take loratadine for a short time or as a one-off dose. If you have a reaction to an insect bite, you may only need to take loratadine for a day or two.

You may need to take it for longer if you're taking it to prevent hay fever symptoms when the pollen count is high.

Talk to your doctor or pharmacist if you're not sure how long you need to take loratadine for.

Is it safe to take loratadine for a long time?

Loratadine is unlikely to do you any harm if you take it for a long time. However, it's best to take it only for as long as you need to.

Can I drink alcohol with it?

It's best not to drink alcohol while you're taking loratadine, as it can make you feel sleepy.

Is there any food or drink I need to avoid?

You can eat and drink normally while taking loratadine.

Can I drive or ride a bike with it?

Loratadine is classed as a non-drowsy antihistamine but it's still possible to feel sleepy after taking it.

If this happens to you, do not drive a car or ride a bike until you feel better.

It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.

Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking loratadine. GOV.UK has more information on the law on drugs and driving.

What's the difference between loratadine and other antihistamines?

Loratadine is known as a non-drowsy antihistamine. It's less likely to make you feel sleepy than other, so-called, sedating antihistamines such as Piriton (chlorphenamine).

Most people prefer to take a non-drowsy antihistamine instead of a sedating one. An exception is when you want the medicine to make you sleepy – for example, if you have itchy skin that's keeping you awake.

What's the difference between loratadine and other non-drowsy antihistamines?

Other non-drowsy antihistamines like cetirizine, desloratadine, fexofenadine and levocetirizine seem to work as well as loratadine.

However, loratadine, desloratadine and fexofenadine seem to be less likely to make you feel sleepy than cetirizine.

Can I take it with painkillers?

Yes, you can take loratadine together with paracetamol or ibuprofen.

Can I take 2 different antihistamines together?

Sometimes, doctors recommend that people with a severe, itchy skin rash take 2 different antihistamines together for a few days.

As well as taking a non-drowsy antihistamine like loratadine during the day, your doctor may tell you to take a sedating antihistamine at night if the itching is making it difficult to sleep.

Do not take 2 antihistamines together unless recommended by your doctor.

Can I take loratadine with other hay fever treatments?

Yes, it's fine to take loratadine together with some other types of hay fever treatment, including steroid nasal sprays (such as Beconase, Rhinacort Aqua and Flixonase Nasules), or eyedrops.

Can I take loratadine at higher doses than on the packet?

Your doctor might suggest you or your child take a higher dose of loratadine (up to 4 times the usual dose) for severe itchy skin rash or swelling underneath the skin (angioedema).

Taking high doses of loratadine is not suitable for everyone though.

Speak to your doctor if you think loratadine is not working for you.

Will it affect my fertility?

There's no evidence to suggest that taking loratadine will reduce fertility in either men or women.

However, speak to a pharmacist or your doctor before taking it if you're trying to get pregnant.

Will it affect my contraception?

Loratadine will not affect any type of contraception, including the combined pill, progestogen-only pill or emergency contraception.

Can lifestyle changes relieve hay fever?

It will help if you do not spend too much time outside if the pollen count is high.

Tips for when you're outside

  • Do not cut grass or walk on grass.
  • Wear wraparound sunglasses to stop pollen getting into your eyes.
  • Put Vaseline around your nostrils to help trap pollen.
  • Shower and change your clothes after you've been outside to wash off pollen.

Tips for when you're inside

  • Keep windows and doors shut as much as possible.
  • Vacuum regularly and dust with a damp cloth.
  • Do not keep fresh flowers in the house.
  • Do not smoke or be around smoke as it makes hay fever symptoms worse.