Medication features:

  • A proton pump receptor
  • Suppresses prolonged gastric acid secretion
  • A generic drug


Available strengths:

20 mg 40 mg


Price £17.99

Includes free private prescriptions

In stock

Delivery Time


Expected delivery date:

Friday, 8 December 2023

If you order within:


Next Day Delivery

Next Day

Quick Assessment


UK Registered Pharmacy

UK Registered

Discreet & Confidential

Discreet &

  • Overview
  • FAQ
  • Side Effects
  • Patient Information Leaflet
  • Reviews

What is Omeprazole

Omeprazole belongs to the family of drugs acting at the proton pump receptor. Thus they are used to suppress prolonged gastric acid secretion. The medication istypically administered to sufferers of stomach ulcers, heartburn, gastroesophageal reflux disease (GERD).

How should I take Omeprazole?

Omeprazole is taken orally in the form of tablets or capsules, as well as suspension, which is administered using a syringe. Usually, the medication is taken once a day, first thing in the morning. It does not upset the stomach, so that you can take it before or after a meal.

Note that pharmacists and doctors do not recommend taking the medication for immediate relief of acid reflux symptoms, particularly heartburn. Instead, it should be taken for 4 to 8 weeks, but some patients may end up taking for 14 weeks, depending on the severity of the symptoms. Also, it may take several days for this medication to alleviate stomach pains which is why it should be taken with antacids, as advised by the doctor. If you are taking sucralfate, take omeprazole half an hour before sucralfate. 

When taking omeprazole capsules/tablets, you should not chew or crush them in food since doing so prevents the activation of the medicinal properties of the drug. If unable to swallow the capsules, some brands of omeprazole capsules can be opened, and the contents mixed in a small amount of water that should be taken right away.  You should take to a pharmacist to know which type of capsules can be opened. 

If you forget to take the medication, take it as soon as you remember. However, if it is within 12 hours to your next dose, you can skip the missed dose. It would be best if you didn't take a double dose to make up for a forgotten dose.

How long should I take Omeprazole before I notice any difference?

It takes 2 to 4 days of consumption to realize the full effect, as such, it should not be taken to provide immediate relief. Instead, it is meant to treat acid reflux symptoms occurring a couple of times in a week. Usually, omeprazole is prescribed for 8 weeks when treating short-term gut conditions, but the period can be extended to 14 weeks if the patient's condition does not improve. 

If you are self-medicating, you should not take omeprazole for more than 2 weeks unless advised otherwise by a pharmacist or doctor.

What are the side effects of Omeprazole?

Similar to other PPIs, most patients well tolerate omeprazole. However, it causes some mild side effects on a few patients, which fade away with time. 

Some of these common side effects include:

  • Diarrhoea

  • Nausea

  • Headaches

  • Rash

  • Abdominal pain

In addition to these effects, younger patients, aged 1 to 17 years, complain about fever and breathing issues such as pharyngitis and sinus infections. 

Using omeprazole for an extended period, more than 1 year, can make it difficult for your body to absorb vitamin B-12. The deficiency manifests itself through feeling nauseated, numbness, poor muscle coordination and changes in menstruation cycle. Serious side effects that should warrant a visit to the doctor include bone fractures, severe diarrhoea, pale skin and swellings in the mouth. 

If you experience any of these severe side effects, be sure to consult us at Click Pharmacy for urgent assistance.

When shouldn't I take Omeprazole?

You should not take this treatment if you are on any antifungal, blood thinning, and anti-epilepsy medications. Heart-related drugs, such as digoxin and some antibiotics, do not go well with omeprazole. These medications make it more likely to develop severe omeprazole side effects. Thus you should inform your doctor if you are on any medication before beginning omeprazole treatment. 

Nonetheless, the treatment is safe for pregnant and nursing mothers. But first, you are advised to try alternative treatment methods, such as eating smaller meals and less spicy foods, to ease acid reflux symptoms before you can start treatment.

What is the difference between Omeprazole and Nexium/Aciphex?

Omeprazole and Nexium as well Aciphex are similar since they are all proton pump inhibitors. They can be prescribed to treat ulcers and GERD. 

The only difference is in their active ingredient component. Both omeprazole and Nexium contain the same active ingredient, but omeprazole contains two isomers of the ingredient while Nexium contains only one isomer. Aciphex, on the other hand, contains rabeprazole as the active ingredient, which is also under the proton pump inhibitor class of medications. 

How effective is Omeprazole?

Omeprazole is an approved brand and generic drug that is used to treat a variety of digestive conditions caused by excessive production of gastric acid. The active ingredient, which also goes by the same name as that of the drug, omeprazole is highly effective in preventing the secretion of excess gastric acid. This allows the intestinal and stomach ulcers to heal as well as relieving heartburn discomfort when used as advised.

Can I buy Omeprazole online?

Although omeprazole is often available as a prescribed drug, you can still buy over-the-counter omeprazole tablets/capsules. These tablets are used to treat frequent heartburn that occurs a few times within a given period. 

You can buy the tablets online packs of 28 tablets that can be sent to you by Next Day Delivery. You are free to book an appointment with a health expert at Click Pharmacy to discuss how best to use this drug.

What dose should I choose?

A pack of omeprazole tablets come in 28 tablet size. Each of these tablets contains 20 or 40 mg of the active ingredient omeprazole, which should be taken once daily for at least 4 weeks by patients above 18 years. 


How does Omeprazole work?

The active ingredient omeprazole works by targeting proton pumps in your stomach, hence its classification under proton pump inhibitor class of drugs. These tiny pumps are responsible for the chemical reaction that produces stomach acid. Once omeprazole is ingested, it is absorbed in the bloodstream and signals the acid-forming cells on the stomach lining to reduce the amount of acid they produce. With the acidity reduced, the patient is relieved of acid reflux symptoms, and the intestinal ulcers start healing.

Who is not suitable for Omeprazole?

Omeprazole may not be suitable for certain individuals. Consult your GP before taking it. Do not use the medication if you:

  • are taking phenytoin or warfarin-type anticoagulants
  • are taking medication to treat HIV or AIDS
  • are doing chemotherapy for cancer chemotherapy
  • are using high doses of methotrexate

Omeprazole may interact with other medications. Make sure to inform your GP of the medications you are taking. Even if they are not prescribed.

In addition to this, stop the use of the treatment and seek medical attention right away if you experience any of the following:

  • unintended weight loss,
  • vomiting,
  • blood in the vomit,
  • dark, tarry stools,
  • persistent diarrhoea

Are there any drugs which might interact with Omeprazole?

Various drugs may interact with Omeprazole. Do not use the treatment unless you are advised to do so by your GP. This is because Omeprazole can lead to a significant decrease or an increase in the levels of certain drugs in your bloodstream.

Omeprazole may decrease the efficacy of the following drugs in your bloodstream:

  • Nelfinavir, rilpivirine, and atazanavir
  • Clopidogrel
  • Dasatinib, gefitinib, neratinib, erlotinib

On the other hand, Omeprazole may increase the efficacy of the following drug levels in your bloodstream:

  • Saquinavir and ritonavir
  • Tacrolimus
  • Methotrexate
  • Citalopram, escitalopram
  • Digoxin
  • Diazepam
  • Cilostazol

However, note that certain drugs can increase or decrease the efficacy of Omeprazole itself.

Keeping that in mind, medicines which may decrease omeprazole levels are:

  • Rifampicin
  • St John's Wort - a herbal remedy
  • Tipranavir

Similarly, medicines which amplify the efficacy of Omeprazole levels are:

  • Clarithromycin
  • Voriconazole

Alternatives to Omeprazole

In case Omeprazole does not work for you or is not suitable for you; opt for one of the direct treatment alternatives. You can find various alternative acid reflux medicines such as:

  • Lansoprazole
  • Esomeprazole
  • Pantoprazole

Similarly, you can try a few natural alternatives to Omeprazole to further alleviate painful symptoms. If your body tends to produce an excessive amount of stomach acid, there are certain changes that you can implement in your lifestyle and diet. You can combine them with your treatment or try them without the need of taking medicine. These include:

  • maintain a healthy weight
  • avoid foods that trigger symptoms or worsen them, such as spicy and fatty foods
  • avoid consuming caffeinated drinks, such as tea and coffee
  • stop smoking
  • avoid eating at least 3 hours before going to bed

Can I buy Omeprazole over the counter?

No. Omeprazole is a prescription-only treatment. Therefore, it is crucial that you have a valid prescription in order to purchase it. However, note that if you do not have a valid prescription from your GP or a pharmacist, you can fill out a survey on our website. Our on-site experts will assess the completed survey and determine whether the treatment suits you. Once verified, we will dispatch your order of Omeprazole.

Does Omeprazole cause weight gain?

Yes. Omeprazole can cause weight gain. In addition, long-term use of the treatment can lead to fluctuations in weight.

Can pregnant and breastfeeding women use Omeprazole Capsules?

Yes, it is safe for pregnant and breastfeeding women to use Omeprazole Capsules.

Can everyone use Omeprazole Capsules for the treatment of indigestion and heartburn?

Although Omeprazole Capsules are a safe medicine, they are not suitable for everyone to use. You should not use Omeprazole Capsules if you have any of the following:

  • Problems with your liver
  • Due to have an endoscopy

When should I take Omeprazole Capsules?

It is usually advised to take one Omeprazole Tablet first thing in the morning. For severe cases it is sometimes prescribed to be taken twice a day, once in the morning and evening.

When should I stop taking Omeprazole Capsules?

It is recommended to stop taking Omeprazole Capsules once you feel better.

Can I take other medicines with Omeprazole Capsules?

Although Omeprazole Capsules are often safe to combine with other drugs, there are a few drugs you should not combine with Omeprazole Capsules. They include the following:

  • Blood thinning medicines
  • Rifampicin
  • Phenytoin
  • HIV medicines
  • Methotrexate
  • Antifungal medicines
  • Cilostazol
  • Heart medicines

After using Omeprazole Capsules you are likely to experience lots of different side effects. Common side effects and how to overcome them include the following:

  • Headaches: rest and drink plenty of water to ensure you are hydrated
  • Feeling sick: take your medication after a meal or snack
  • Diarrhoea: drink lots of fluids to prevent dehydration
  • Stomach pains: eat smaller more frequent meals
  • Constipation: try to increase your intake of foods that contain lots of fibre
  • Wind: avoid foods such as lentils, beans and cereals.

Always read the patient information leaflet before starting your treatment. The patient information can be found here.

Authored by

Last reviewed 11 April 2023

Superintendent Pharmacist GPhC No.2220953

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