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Losec

Losec is the branded version of Omeprazole. It is used to treat conditions such as chronic acid reflux, stomach ulcers, gastroesophageal reflux disease (GORD) and heartburn. It works by preventing certain cells within the stomach lining from producing acid. This leads to a decrease in gastric acid refluxing into the gullet (oesophagus), causing symptoms associated with all the conditions above. It is recommended that the patient take the daily dose regularly to achieve their most effective therapeutic results.

Buy Losec Capsules Online

Losec 20 mg hard gastro-resistant capsules, a brand name of Omeprazole, is a drug that is used to help reduce the production of stomach acid to inhibit the symptoms of acid reflux and indigestion.

This particular brand is available in both full-strength and half-strength Omeprazole. It is a medicine that belongs to the family of drugs known as proton pump inhibitors (PPIs).

When to Use Losec Hard Capsules?

As a type of Proton Pump Inhibitors (PPIs), Losec Hard Capsules are beneficial for reducing the acid that builds up in the stomach. They treat the following conditions:

  • Acid Reflux: GORD - also known as gastro-oesophageal reflux, is when stomach acid flows into the food pipe, which causes ongoing pain. It can treat your immediate symptoms while also preventing the symptoms from recurring.
  • Ulcers: Losec Capsules are also beneficial for treating ulcers in the stomach and intestines.
  • Infections: Treatment for H. pylori infections often combines PPIs with antibiotics.
  • Zollinger-Ellison Syndrome: People with this condition produce too much acid, which can cause ongoing pain.

Age Restrictions For Losec Capsules

Losec capsules can be prescribed for children over 1 year who weigh at least 10 kg. Children weighing 10 to 20 kg usually start on 10mg a day, and children aged 2 and over who weigh more than 20 kg usually take 20mg a day. Over-the-counter purchases are restricted to adults aged 18 and over.

How to Use Losec (Omeprazole) 20mg?

When using Losec capsules, please follow these instructions:

  • Take a capsule in the morning, with or without food.
  • In most cases, you'll take one capsule a day. However, a doctor may prescribe a higher dose for certain conditions.
  • Swallow the capsules whole with half a glass of water; do not crush or chew them. If you have difficulty swallowing, you can open the capsule and take the contents with half a glass of water, or mix them with a slightly acidic fluid such as fruit juice or applesauce, or with non-carbonated water. Take the mixture within 30 minutes.
  • If your GP prescribes the capsules, complete the full treatment course, even if you feel better. OTC users shouldn't take the capsules for more than 14 days.

When to Avoid Using Losec 20mg?

There are some cases when you should avoid using Losec. These include:

  • Allergies: If you're sensitive or allergic to any of the ingredients in Losec or have reacted to other PPI medications, you should avoid using them, as they can cause a severe allergic reaction.
  • HIV Medicines: Do not take Losec if you take nelfinavir (an HIV medicine). Taking it with atazanavir (another HIV medicine) is not recommended.
  • New Symptoms: If you experience sudden weight loss, difficulty swallowing, black or bloody stools, or any other symptoms, you should see a doctor, as these could be signs of an underlying condition.

Precautions For Losec Capsules

The following don't necessarily mean you can't use Losec, but you should consult a medical professional beforehand:

  • Medications: Taking Losec with clopidogrel (a medicine that prevents blood clots) is not recommended, as Losec can make it work less well. Losec can also reduce how well your body absorbs some antifungal medicines (ketoconazole, itraconazole and posaconazole), and your doctor may need to check you more closely if you take warfarin.
  • Liver Problems: If you have a condition that affects the liver, your GP will probably recommend a lower dose of a PPI.
  • Osteoporosis: If you use PPIs long-term, it can increase your risk of developing osteoporosis later in life.
  • Magnesium Deficiency: PPIs can impact your body's ability to absorb magnesium. Individuals with low magnesium levels may need to take a daily supplement.
  • Pregnant/Breastfeeding Women: If you're pregnant or breastfeeding, please ask your healthcare provider for advice before using the medicine.

Ingredients Of Losec Capsules

The active ingredient in Losec Hard Capsules is Omeprazole (20mg). As a Proton Pump Inhibitor, it suppresses the production of stomach acid.

Inactive Ingredients Include:

  • Disodium phosphate dihydrate
  • Hypromellose
  • Methacrylic acid - ethyl acrylate copolymer (1:1) dispersion 30%
  • Hydroxypropyl cellulose
  • Magnesium stearate
  • Microcrystalline cellulose
  • Lactose anhydrous (each capsule contains 8 mg lactose; do not take if you have galactose intolerance, lactase deficiency or glucose-galactose malabsorption)
  • Sodium lauryl sulfate
  • Mannitol
  • Gelatin
  • Iron oxide red (E172)
  • Titanium dioxide (E171)
  • Iron oxide yellow (E172)

Side Effects Of Losec Capsules

There is always a risk of side effects with all medications. Some of these can be quite mild and can subside over time. Others are more serious and should be reported to your GP right away if you experience any side effects.

Please contact a member of our team if you are concerned about any potential side effects while taking Losec.

Common side effects include:

  • Nausea
  • Diarrhoea
  • Abdominal pain
  • Constipation
  • Headache
  • Vomiting
  • Wind (flatulence)
  • Harmless (benign) polyps in the stomach

Uncommon side effects include:

  • Dizziness

Rare side effects include:

  • Dry mouth
  • Muscle pains

Very rare side effects include:

  • Muscle weakness

There are some rare yet severe side effects associated with Losec, including a severe allergic reaction or severe liver disease.

You should seek medical attention if you experience any adverse effects, including yellow skin, difficulty breathing, or joint pain, along with a red skin rash, especially in areas of your body exposed to the sun, such as your arms, cheeks, and nose.

Other adverse reactions include: Stevens-Johnson syndrome and toxic epidermal necrolysis.

What are Losec capsules used to treat?

Losec capsules are used to treat:

  • Gastric and duodenal ulcers
  • Relapse of duodenal ulcers
  • Gastric ulcer
  • Reflux oesophagitis
  • Symptomatic gastroesophageal reflux disease
  • Zollinger-Ellison syndrome
How does Losec treat duodenal ulcers?

For patients with duodenal ulcers, the recommended dose is Losec 20 mg capsules taken once daily. Ulcers should begin to heal within two weeks.

If ulcers don't clear up within that time, a further two-week treatment can be prescribed. If necessary, Losec 40 mg capsules can be prescribed.

To prevent a relapse of a duodenal ulcer, the recommended daily dose is 20 mg once daily.

How does Losec treat gastric ulcers?

For patients with gastric ulcers, the recommended daily dose is 20 mg, taken once daily. Treatment is usually effective within four weeks.

How does Losec treat NSAID-associated gastric and duodenal ulcers?

For effective treatment of NSAID-associated gastric and duodenal ulcers, the recommended daily dose is 20 mg.

How do Losec capsules treat acid reflux?

Again, the recommended daily dose for effective treatment is 20 mg, with a healing time of approximately four weeks.

What is the difference between prescription and over-the-counter PPIs?

Both prescription and over-the-counter PPIs contain the same active ingredients. They work in the same way, but OTC medications may contain a lower dose than Losec (omeprazole).

Are PPIs Safe?

Long-term use can cause severe proton pump inhibitor side effects. Kidney disease, bacterial infections and bone fractures are some of the PPIs’ most serious side effects.

You should only use this medication long-term if advised to do so by a healthcare professional.

Do not take PPIs if you have a hypersensitivity to the active substance or any of the listed ingredients, including magnesium stearate, silica colloidal anhydrous, potassium hydroxide, lactose anhydrous, polyethene glycol, ethyl acrylate copolymer, black iron oxide, cellulose microcrystalline, disodium phosphate dihydrate, titanium dioxide, sodium laurilsulfate, and methacrylic acid.

Proton pump inhibitors have been associated with cases of subacute cutaneous lupus erythematosus. If lesions occur, discontinue PPI use.

How do you take a proton pump inhibitor like Losec (omeprazole)?

Take Losec in the morning, swallowed whole with half a glass of water. Do not chew or crush the capsules. You can take it with or without food. If you miss a dose, take it as soon as you remember. If it's less than four hours until your next dose, do not take it.

How long will I have to keep taking proton pump inhibitors?

PPIs are generally taken for 2 to 8 weeks, depending on the condition being treated.

How long you take Losec depends on the condition being treated, and your prescriber will set the length of your course. Some people take it long term, for example to stop reflux oesophagitis or ulcers from coming back.

Can I take Losec while breast feeding?

Losec is excreted in breast milk. While it is unlikely to affect the child, speak to your doctor immediately if you have any concerns.

Losec Capsules Patient Information Leaflets

Before taking any medicines, whether over the counter or prescription-only, it is essential to read the Patient Information Leaflet.

If you have any questions or need advice, please feel free to contact our registered pharmacists today. We're here to simplify your health journey.

Patient Information Leaflet

Umar Razzaq, MPharm | University of Strathclyde, Clinical Pharmacist.
Content Written by:Umar RazzaqMPharm | GPhC Reg: 2064448 | University Of Strathclyde
Date Written:12/06/2026
Role:Clinical Pharmacist
Nish Fayyaz, MPharm | University of Strathclyde, Pharmacist.
Medically Reviewed By:Nish FayyazMPharm | GPhC Reg: 2225257 | University Of Strathclyde
Date Checked:12/06/2026
Role:Pharmacist
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