Can Magnesium Supplements Cause Heartburn? How to Choose the Right Form

October 26, 2025 •

3 min read

While some magnesium compounds are used in antacids to relieve heartburn, some individuals find that certain magnesium supplements can cause heartburn or other gastrointestinal upset. Understanding the different forms and their effect on the digestive system is key to supplementing safely and effectively.

Quick Summary

Certain magnesium forms like oxide and citrate can cause stomach upset and heartburn, particularly at higher doses. Choosing gentle, bioavailable types like glycinate and taking them with food can help minimize the risk of digestive side effects.

Key Points

Form Matters: Certain forms of magnesium, notably oxide and citrate, are more likely to cause heartburn and other digestive issues due to poor absorption.
Gentle Alternatives: Highly absorbable forms like magnesium glycinate and malate are less likely to cause stomach upset and are recommended for those with sensitive digestive systems.
Dosage is Key: High doses of any magnesium supplement can overwhelm the digestive system and cause side effects, including heartburn.
Take with Food: Taking your magnesium supplement with a meal can help buffer its effects on the stomach and reduce the risk of discomfort.
Individual Sensitivity: Responses to magnesium supplements vary by individual, so paying attention to your body's reaction and adjusting accordingly is crucial.
Potential for Relief: In contrast to causing heartburn, magnesium in antacid formulations can neutralize stomach acid and relax the lower esophageal sphincter, providing relief.

The Complex Link Between Magnesium and Heartburn

Magnesium is an essential mineral involved in numerous bodily functions, including nerve and muscle function, and bone health. Its relationship with heartburn is two-sided: it can be used to treat it, but certain forms may also cause it. For some individuals, especially those with sensitive stomachs, high doses or specific types of magnesium can lead to discomfort.

Magnesium hydroxide and carbonate are used in antacids to neutralize stomach acid. Magnesium is also important for muscle relaxation, including the lower esophageal sphincter, which helps prevent acid reflux. Low magnesium levels might even be linked to increased acid reflux symptoms.

Conversely, some magnesium supplements can cause digestive issues. Certain magnesium salts draw water into the intestines, leading to a laxative effect, which can result in cramps and diarrhea. This gastrointestinal distress can sometimes be felt as heartburn or acid reflux, particularly if the stomach lining is already irritated.

How Different Forms of Magnesium Affect Digestion

The form of magnesium supplement you choose can greatly influence how your digestive system reacts. Some forms are poorly absorbed and more likely to cause issues, while others are gentle and easily utilized by the body.

High-Risk Forms for Heartburn

Magnesium Oxide: This form is common and inexpensive but has low bioavailability. Its poor absorption means more of it stays in the gut, often causing diarrhea, stomach upset, and cramping, which can worsen heartburn.
Magnesium Citrate: Known for its laxative effect, magnesium citrate can irritate a sensitive digestive system. High doses can cause digestive distress that may lead to acid reflux symptoms.

Gentle, Bioavailable Forms

Magnesium Glycinate: Bound to glycine, this form is highly absorbed and less likely to cause digestive side effects. It is a good choice for those with sensitive stomachs or a history of heartburn with other forms.
Magnesium Malate: This combination with malic acid is also well-absorbed and gentler on the digestive system than oxide or citrate. It provides sustained magnesium absorption with a lower risk of stomach upset.

Factors That Can Worsen Magnesium-Induced Heartburn

Several factors besides the type of magnesium can increase the likelihood of heartburn:

High Dosage: Taking more than the recommended daily upper limit of 350 mg from supplements can overwhelm the digestive system. Starting with a lower dose is advisable.
Empty Stomach: Taking magnesium supplements without food can increase the chance of digestive upset and heartburn. Eating beforehand can help.
Individual Sensitivity: People react differently to supplements; some may be more sensitive to certain forms or ingredients.

Comparison of Magnesium Supplement Forms


Magnesium Form	Bioavailability	Gastrointestinal Side Effects	Best For	Risk of Heartburn
Magnesium Oxide	Low (poorly absorbed)	High; diarrhea, cramping, upset stomach	Short-term relief of constipation or as an antacid ingredient	High (due to GI irritation)
Magnesium Citrate	Moderate to High	High; strong laxative effect	Occasional constipation relief	Moderate to High (due to laxative effect)
Magnesium Glycinate	High (easily absorbed)	Low; generally well-tolerated	Long-term daily use for deficiency, sleep, relaxation	Low
Magnesium Malate	High (easily absorbed)	Low; gentle on the digestive system	Overall magnesium support, sustained absorption	Low

How to Minimize Heartburn from Magnesium Supplements

If you experience discomfort from magnesium supplements, consider these strategies:

Take with food: This helps slow absorption and protects your stomach.
Start with a lower dose: Gradually increase your dosage as your body adjusts.
Switch forms: If oxide or citrate cause heartburn, try glycinate or malate.
Split dosage: Divide your daily dose into smaller amounts taken throughout the day.
Stay hydrated: Drinking water aids digestion and can lessen laxative effects.

Conclusion: Finding the Right Balance for Your Body

Magnesium is vital for health and can even help with digestive issues, but some supplements can cause heartburn depending on the form, dose, and timing. By choosing highly absorbable forms like glycinate over less tolerated ones like oxide, you can lower your risk of side effects. It's always best to talk to a healthcare provider before starting any new supplement to ensure it's right for you. The goal is to get the benefits of magnesium without the discomfort.

Visit Healthline for more detailed information on magnesium and acid reflux.

Frequently Asked Questions

Magnesium glycinate is the form least likely to cause heartburn because it is highly bioavailable and gentle on the digestive system.

Forms like magnesium oxide and citrate are poorly absorbed and can cause digestive side effects like diarrhea and cramping. This gastrointestinal irritation can sometimes manifest as heartburn.

To prevent heartburn, choose a gentle form like magnesium glycinate, take your supplement with food, and start with a low dose while gradually increasing it.

Yes, taking magnesium on an empty stomach can increase the likelihood of digestive upset and heartburn symptoms, especially with poorly absorbed forms.

For most people, it is better to take magnesium supplements with food, as this can help buffer the mineral's effects on the stomach and reduce the risk of digestive discomfort.

Some evidence suggests that low levels of magnesium may be linked to acid reflux, as the mineral helps relax the esophageal sphincter and balance stomach acid.

No, magnesium antacids (which contain forms like magnesium hydroxide or carbonate) are designed for short-term, immediate relief by neutralizing stomach acid, while supplements are for longer-term dietary support.

Digestive issues like nausea, diarrhea, and stomach pain are more likely with supplemental doses over the Tolerable Upper Intake Level (UL) of 350 mg per day, though some may be sensitive at lower doses.