Does Omeprazole Go Bad

In this brief article, we will answer the question, “does omeprazole go bad?”, and will also tell you what this medicine is, what it does, how to use it, its side effects, and how to dispose of medicines safely. 

Does Omeprazole Go Bad?

Not exactly; you may still use omeprazole after it’s past its expiration date but it might have lost some of its potency and will not deliver similar results as before.

A study on the stability of omeprazole demonstrated that at 25°C, omeprazole reaches 90% concentration after 12 months, if stored protected from light and 8.5 months, if stored exposed to light (1).

What’s important to remember is that expiration dates for medicines do not mean that the medication will go bad after that date. They just indicate that the medicine will not work as effectively.

Other than a handful of medications, most of which are rarely available commercially, commonly used medications do not spoil or become toxic after their expiration date.

How Can You Prevent Omeprazole From Going Bad?

A medication’s shelf life, or expiration date, is the time frame in which a medication has been proven safe and effective despite exposure to various environmental factors including temperature, humidity, and light. Many medications may have much longer shelf lives than labeled. In the 1980s, the FDA tested various batches of the medications in their supplies to provide extensions in shelf life. In their studies of 122 different medication products, nearly 90% met the requirements for an extension. Some of them were extended by more than 20 years (2).

However, to prevent omeprazole, and generally most medicines, from losing their potency before their approximate expiry date, it’s important that you keep them stored in a cool, dark place away from direct sunlight, heat or fluctuating temperatures, humidity, and moisture.

Unless mentioned otherwise, do not freeze medicines or place them in the refrigerator.

 What is Omeprazole and How Does It Work?

Omeprazole is a type of ‘proton pump inhibitor’. These medicines work by lowering the production of acid in the stomach by inhibiting a mechanism inside it known as the proton pump. It is the first “proton pump inhibitor” widely used in the prophylaxis and treatment of gastroduodenal ulcers and the treatment of symptomatic gastroesophageal reflux. It interacts with H+/K+ ATPase in the secretory membranes of the parietal cells (1). 

The stomach produces acid that helps break down food for easy digestion. In some cases, this acid irritates the lining of the large intestine, leading to complications such as indigestion, ulceration, and even bleeding.

Omeprazole helps in relieving symptoms of indigestion and heartburn, and also allows the irritated stomach lining to heal.

The inhibitory effects of omeprazole occur rapidly within 1 hour of administration, with the maximum effect occurring in 2 hours. The Inhibitory effects last for approximately 72 hours after administration, followed by a return to baseline activity in 3 to 5 days (3).

Who Should Not Take Omeprazole?

You shouldn’t take omeprazole under the following circumstances (3):

  • If you are allergic to any of the active ingredients in omeprazole. Some of the signs of an allergic reaction to omeprazole include difficulty breathing, skin rash, swelling (particularly of the face), and fainting. 
  • If you are (or think you could be) pregnant, and if you are breastfeeding since the medicine may be absorbed into breast milk.
  • If the packaging shows signs of tampering or hasn’t been stored under the appropriate conditions.
  • If you use medications that are available without a prescription from a supermarket, pharmacy, or health food shop. Also, the following medications might interfere with the functioning of Omeprazole: 
  • phenytoin
  • warfarin
  • diazepam
  • ketoconazole, itraconazole, and voriconazole
  • clarithromycin
  • antiretroviral drugs (atazanavir, nelfinavir)
  • tacrolimus
  • clopidogrel

Long-term and multiple daily dose omeprazole treatment may have connections with an increased risk for osteoporosis-related fractures of the hip, wrist, or spine (3).

How Should I Take Omeprazole?

The exact dosage of Omeprazole will be prescribed by a doctor, but it usually helps relieve symptoms in about four weeks. The medicine should be swallowed with water preferably before taking a meal and should be taken at the same time every day. Also, chewed or crushed medicine will not deliver the same effects.

If you forget a dose, take it as soon as you remember. Do not double dose to make up for a missed dose. 

Taking too much omeprazole can result in adverse overdose symptoms, including:

  • reduced heart rate
  • difficulty breathing
  • a sudden decrease in blood pressure or blood sugar

If any of these symptoms persist or become worse, immediately contact emergency services. 

Does Taking Omeprazole Have Any Side Effects?

Yes. Like most medicines, Omeprazole can also have the following common side effects:

  • Constipation or diarrhea 
  • Nause
  • Abdominal pain
  • Headache
  • Skin rash

Some other risks are (3):

  • Proton pump inhibitors (PPI) therapy may correlate with an increased risk of Clostridioides difficile (C. diff)associated diarrhea.
  • There are rare reports of hypomagnesemia with prolonged treatment with PPIs.
  • There is an increased risk of drug resistance or toxic effect of antiretroviral medicines when used with omeprazole.
  • According to product labeling, warnings and precautions are advised for patients who develop acute tubulointerstitial nephritis, cyanocobalamin deficiency, and cutaneous or systemic lupus erythematosus while on omeprazole.

If you notice the following more serious side effects of Omeprazole, immediately contact your physician:

  • Muscle weakness or ‘pins and needles’
  • Dizziness
  • Disturbed sleep 
  • Mood swings
  • Increase in breast size (in males)
  • Fever
  • Bruising
  • Pain or indigestion
  • Passing black (blood-stained) stools

How Should You Dispose Of Omeprazole?

Medicine that’s compromised or is past its expiration date must never be thrown away directly. Follow these simple steps to discard medicines safely:

  1. Remove the medicine from its original packaging.
  2. Mix the medicine with something dirty, such as mud or cat litter. 
  3. Place the soiled medicine in an airtight bag or container. Make sure it is tightly sealed. 
  4. Throw it in the garbage. 

Recent US study concluded that the disposal of unused medications in municipal solid waste landfills which meet strict US regulations, effectively eliminates the unused medicine contribution of pharmaceuticals to surface waters (4).

Although flushing medication in the toilet can be harmful and potentially pollute water bodies, the US Food and Drug Administration deems it an acceptable method to discard medicines. The least favorable route of drug disposal is disposable via drain, leading to direct input of pharmaceuticals into the aquatic environment, with unpredictable acute and especially chronic effects of active compounds, their mixtures and metabolites on environmental organisms (4).


In this brief article, we answered the question, “does omeprazole go bad?”, and also told you what this medicine is, what it does, how to use it, its side effects, and how to dispose of medicines safely. 

If you have any more questions or comments please let us know.


  1. Iuga, Cristina, and Marius Bojita. Stability study of omeprazole. Farmacia, 2010, 58, 203-210.
  2. Diven, Dayna G., Diana W. Bartenstein, and Daniel R. Carroll. Extending shelf life just makes sense. Mayo Clinic Proceed., 2015, 90.  
  3. Shah, Neal, and William Gossman. Omeprazole. 2019.
  4. Paut Kusturica, Milica, Ana Tomas, and Ana Sabo. Disposal of unused drugs: Knowledge and behavior among people around the world. Rev Environ Contam Toxicol, 2016, 240, 71-104.