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Omeprazole Magnesium: Benefits, Side Effects & Low Mg Levels


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Omeprazole magnesium is a medication used to treat stomach and esophagus problems like acid reflux, heartburn, and ulcers. Omeprazole belongs to a class of drugs known as proton pump inhibitors or PPIs, and this medication is available under multiple brand names and in several forms.  

This medication works by decreasing the amount of acid your stomach produces by blocking a system in the cells of your digestive tract called the proton pump. The proton pump acts during the final step of acid production, and when the proton pump is blocked, your stomach makes less acid. This can decrease your digestive symptoms.

In this post, we’ll talk about the benefits of taking omeprazole magnesium, discuss some of the common side effects, and explore how taking magnesium citrate may be a better option for treating stomach upset and digestive issues.

Benefits of Omeprazole Magnesium

Some conditions like ulcers of the stomach and intestines (duodenal and gastric ulcers) require a reduction in acid secretion for proper healing — in these cases, omeprazole magnesium can be an effective medication. 

Omeprazole magnesium is also used to treat and prevent ulcers caused by non-steroidal anti-inflammatory drugs (NSAIDs), Zollinger-Ellison syndrome, gastroesophageal reflux disease (GERD), reflux esophagitis, and heartburn. Sometimes this medication is used in combination with antibiotics to treat stomach ulcers that are caused by H. pylori bacteria.

Your dosage and length of treatment with omeprazole magnesium will depend on what condition you’re treating, so talk to your doctor about when and how you should be taking it. 

Potential Side Effects of Omeprazole Magnesium

Common side effects of omeprazole magnesium include headache, stomach pain, nausea, vomiting, and diarrhea. Children might also have fever as a side effect. These symptoms may be mild and go away in a few days. If you are experiencing severe or chronic side effects, talk to your doctor.

Call your doctor or 911 right away if you experience serious side effects, including symptoms of electrolyte imbalance (see below) or you feel you are having a medical emergency. Serious side effects of omeprazole magnesium can include numbness or tingling in your hands and feet, vitamin B-12 deficiency, poor muscular coordination, severe diarrhea, bone fractures, or a raised or red rash on your body.

Our disclaimer: Our goal is to provide you with the most current information possible, but medications affect each person differently. We cannot guarantee that this information includes all possible side effects, and this information is not a substitute for medical advice. Before you start taking any medications, discuss any possible side effects or interactions with your healthcare provider who knows your medical history.

The Effect of Omeprazole Magnesium on Magnesium Levels

It would be logical to assume that omeprazole increases your magnesium levels. After all, “magnesium” is in the name of the medication. However, the opposite may be true.

The primary active ingredient is a compound too complex to discuss here: 5-Methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]sulfinyl]-1H-benzimidazole (Rxlist)

That compound (which inhibits gastric acid secretion) is present with magnesium in a 2:1 ratio.

Most people only take about 20 mg of omeprazole magnesium a day, and the amount of magnesium in that dose is minuscule. (You’d get a little over 6 mg of magnesium from the drug, to be specific).

Rather than increasing magnesium levels, it appears that omeprazole magnesium depletes magnesium and other electrolytes.

Electrolyte Imbalances and Omeprazole Magnesium

Researchers have found that taking omeprazole or other PPIs can cause changes in electrolyte levels in the blood, including sodium, potassium, calcium, and magnesium.

A 2019 study published in Scientific Reports said:

“Hypomagnesemia was reported in the initial clinical trials and on the FDA package insert for every PPI as a rare side effect. Accordingly, the frequency of hypomagnesemia reports for PPI patients is low, but the relative frequency was dramatically higher, almost eighty-fold, than for the H2RA control group.

Secondly, detection bias may underestimate this adverse effect, since magnesium concentrations are not routinely measured compared to sodium, potassium, and calcium. All five studied PPIs had comparable and increased ORs, with omeprazole showing the largest magnitude. Omeprazole, being the first marketed and the first over-the-counter PPI, has been used for the longest time, therefore patients were likely to have longer drug exposure.

It may be prudent to monitor magnesium levels in patients with ongoing PPI therapy and other risk factors for hypomagnesemia.”

Another study in the British Medical Journal (BMJ) noted several cases of hypomagnesemia (low magnesium) in hospital patients that appear to be connected with omeprazole. The study states:

“Although the mechanism remains unclear, there seems little doubt that omeprazole may cause hypomagnesemia. Given the frequency with which this drug is prescribed it would seem likely that use of the drug in the absence of other illness predisposing to electrolyte imbalance does not invariably cause hypomagnesemia, but these cases are unlikely to be isolated. Doctors should consider omeprazole as a possible causative agent when investigating hypomagnesemia.”

If you are taking omeprazole magnesium and experience symptoms of an electrolyte imbalance — such as muscle cramps or weakness, numb hands or feet, a racing heartbeat, jitteriness, tremors, dry mouth, or seizures — contact your doctor immediately. 

Your doctor should run blood tests regularly to monitor your electrolyte levels while you are taking this medication.

Natural Calm® Magnesium Citrate as a Digestive Aid

Natural Calm Magnesium Citrate Flavours e1640622857389

While PPIs work to decrease the amount of acid in your digestive tract, some experts believe that digestive issues like heartburn and Gastroesophageal Reflux Disease (GERD), are actually caused by too little stomach acid.

In her book The Magnesium Miracle, Dr. Carolyn Dean, M.D., N.D., says:

“Heartburn and indigestion, the result of bad eating habits, plague the nation. But the ‘cure’ in this case is no better than the disease. The roiling and burning in the gut from sugary junk food and greasy fast food is being inappropriately blamed on too much stomach acid. In many cases, heartburn is due to sugar fermentation in the stomach and a backflow of pancreatic enzymes from the small intestine.”

Magnesium intake and digestive issues go hand in hand. In order to regulate the body’s production of stomach acid, we need magnesium – and when antacids neutralize normal stomach acids, it reduces our ability to absorb minerals like magnesium from our food.

Some people who are struggling with acid reflux or other digestive issues may benefit from supplementing their diet with magnesium citrate, which aids in digestion because it includes the acid some people with low stomach acid are missing.

Talk to your doctor to find out if supplementing with magnesium citrate could help you resolve your issues without needing to take a proton pump inhibitor medication. 

Award-winning Natural Calm® magnesium citrate powder is an easily-absorbable magnesium supplement that is gentle on your system, even if you have a sensitive stomach. If you are experiencing digestive issues like heartburn or acid reflux, talk to your healthcare provider to see if Natural Calm® might give you relief from your symptoms.


  • Center. “Low Magnesium Levels Can Be Associated with Long-Term Use of PPIs.” U.S. Food and Drug Administration, 2019, Accessed 31 May 2023.
  • “Prilosec (Omeprazole): Uses, Dosage, Side Effects, Interactions, Warning.” RxList, RxList, 22 Mar. 2022, Accessed 31 May 2023.
  • Tigran Makunts, et al. Analysis of Postmarketing Safety Data for Proton-Pump Inhibitors Reveals Increased Propensity for Renal Injury, Electrolyte Abnormalities, and Nephrolithiasis. no. 1, Feb. 2019, Accessed 31 May 2023.
  • N Shabajee, et al. Omeprazole and Refractory Hypomagnesaemia. no. jul10 3, July 2008, pp. a425–25, Accessed 31 May 2023.‌
  • “The BMJ: Leading Medical Research, News, Education, Opinion.”, 2022, Accessed 31 May 2023.
  • “Welcome – Dr Carolyn Dean MD ND.” Dr Carolyn Dean MD ND, 13 Mar. 2023, Accessed 31 May 2023.

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