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Treatment > Medications

Long-term side effects of Omeprazole

Dr. med. André Sommer

Dr. med. André Sommer

If stomach acid attacks the esophagus or the gastric mucosa, this can lead to unpleasant symptoms such as painful or acidic swallowing. The active ingredient Omeprazole is therefore prescribed for heartburn, reflux disease or stomach ulcers, which reduces the quantity of stomach acid. With long-term therapy, however, this can have undesirable consequences. The drug is suspected to promote or trigger dementia and osteoporosis and to damage the liver and kidneys.

What are the side effects of Omeprazole?

Omeprazole is an active ingredient that is used against conditions such as heartburn, reflux disease or stomach ulcers. It inhibits so-called protons in the gastric mucosa from releasing stomach acid and thus reduces the amount of stomach acid in the body. The stomach acid performs important functions: It helps with digestion and kills bacteria in the stomach. The aggressive acid can also attack the esophagus and stomach lining and lead to complaints. Omeprazole protects the irritated stomach lining and esophagus, and relieves symptoms such as acid regurgitation, stomach pain, and nausea.

For heartburn, the drug can be used for a period of two weeks as self-medication and is available in pharmacies up to 20 mg without a prescription. This can lead to effects like sleep disorders or diarrhea, and rarely sweating, hair loss or skin rashes.

However, if the drug has to be taken over a longer period of time and in higher doses such as 40 mg or 80 mg, this can lead to further side effects than usual. Omeprazole is suspected, among other things of promoting osteoporosis and dementia, damaging the kidneys and causing a decline in liver values. In the case of long-term intake, it is therefore advisable to discuss with the doctor beforehand what the risks are and what can be done to counteract the undesirable effects.

What are the typical side effects of Omeprazole?

Typical side effects that can also occur with short-term use are:

  • Gastrointestinal complaints
  • Dysgeusia
  • Headache
  • Vertigo
  • Blurred vision
  • Rash or itching
  • Skin sensitivity to light
  • Sleep disorders
  • Fatigue
  • Tinnitus
  • Sweat
  • Hair loss
  • Benign tumors on the stomach lining
  • Change in liver function values
  • Water retention in arms and legs

The most common side effects that also occur with short-term use of Omeprazole include: Digestive problems Nausea and vomiting Fatigue Vertigo Sleep disorders Headache

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What kind of drug interactions can occur?

If other medications are taken in addition to Omeprazole or if there are already previous illnesses, interactions and undesirable side effects can occur. In this case, the patient should speak to their doctor before starting treatment with the drug. Further information can be found on the product information leaflet.

During pregnancy

Many women experience increased heartburn during pregnancy. During this time and while breastfeeding, however, a doctor must first be consulted regarding whether Omeprazole can be taken. In general, the dosage and duration of use should be kept as low as possible.

Does Omeprazole lead to osteoporosis?

Calcium is an important mineral that mainly serves as a building block for bones and teeth. If the body lacks this building block, broken bones can increase. The deficiency can even trigger what is known as osteoporosis - a type of bone loss, in which the bones can break under everyday stress. Calcium deficiency often develops gradually and remains unnoticed for a long time.

Gastric acid is involved in breaking down nutrients in the stomach. However, the active ingredient Omeprazole reduces the amount of stomach acid in the body. This makes it more difficult for the body to break down calcium and use it in the body. Therefore, anyone who takes the preparation should eat calcium-rich foods. These include milk, yogurt, tofu, kale, broccoli and hard cheese such as Emmental cheese.


Older people are more prone to bone loss - so therapy should be kept as short as possible with them.

However, it takes quite a while until the calcium deficiency in the body is so great that it leads to broken bones or osteoporosis. Those who use the drug in small doses for two weeks as an anti-heartburn remedy need not worry. However, with regular use over five or seven years, the patient should talk to the doctor in advance about how to counteract osteoporosis.

Does Omeprazole lead to dementia and Alzheimer's?

Scientists have not yet fully clarified whether Omeprazole causes dementia or promotes Alzheimer's. However, studies indicate that the long-term use of the drug leads to an increased risk in the development of dementia. Exactly what connection exists has yet to be investigated.

However, one possible cause could be vitamin B12 deficiency: Vitamin B12 is important for the energy metabolism of the cells and helps the blood flow to the brain. If vitamin B12 is missing in the body, it can lead to cognitive damage - such as memory problems, coordination problems or difficulty concentrating. This deficiency increases the risk of dementia in old age. Vitamin B12 cannot be produced by the body itself and is ingested through food. The protein intrinsic factor helps to absorb the vitamin in the metabolism. Omeprazole prevents too much gastric acid from being released into the stomach and settles in the gastric mucosal cells - thus blocking precisely the proteins that are responsible for the absorption of vitamin B12.

Does Omeprazole worsen liver function tests?

Anyone who takes acid blockers like Omeprazole for a long time runs the risk of harming their liver. Among other things, the liver is responsible for converting and eliminating pollutants. However, if the liver is confronted with too many pollutants or even attacked by them, it can no longer function properly. Pollutants remain in the body and weaken the entire body.

Bacteria that enter our bodies through food are usually killed by the aggressive stomach acid directly in the stomach. However, Omeprazole reduces the amount of stomach acid in the body. Bacteria can thus multiply and damage the liver. This can lead to chronic liver diseases. It is particularly critical for the liver when the patient also takes the medication while consuming alcohol, further weakening liver performance. Typical diseases that occur are:

  • Non-alcoholic fatty liver
  • Non-alcoholic inflammation of the liver (steatohepatitis)
  • Acceleration of alcoholic liver damage

Important! Do not take Omeprazole in the following cases: Allergies / intolerances to proton pump inhibitors Previous liver disease Taking medications containing nelfinavir (for HIV infection) A doctor should be consulted if a gastric ulcer is suspected

University of California - San Diego. "Common acid reflux medications promote chronic liver disease." ScienceDaily. ScienceDaily, 10 October 2017. Downloaded on 10.08.2018 from:

Gomm W., von Holt K., Thomé F., 2016. Association of Proton Pump Inhibitors With Risk of Dementia: A Pharmacoepidemiological Claims Data Analysis. Downloaded on 10.08.2018 from:

Dr. med. André Sommer

Dr. med. André Sommer

I’m André, a medical doctor from Berlin. Together with a team of medical doctors, nutritionists and data scientists we empower people to understand digestive issues with our app Cara Care.

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