Which Magnesium Doesn't Cause Stomach Upset? A Guide to Gentle Supplements

December 16, 2025 •

3 min read

According to estimates, up to 75% of Americans do not consume enough magnesium through their diet, yet many are wary of supplements due to common digestive side effects. The key to avoiding stomach upset lies in selecting the right form of magnesium, as different types are absorbed and tolerated by the body in distinct ways.

Quick Summary

Several forms of magnesium are less likely to cause digestive upset than others, particularly chelated options like magnesium glycinate and magnesium malate. The bioavailability and absorption rate of the supplement largely determine its digestive impact. Forms like magnesium oxide and citrate are known for their laxative effects.

Key Points

Magnesium Glycinate is Best: Chelated with glycine, this form is highly bioavailable and the least likely to cause stomach upset or diarrhea.
Avoid Oxide and Citrate: Magnesium oxide and citrate have a strong laxative effect due to low absorption and are unsuitable for sensitive stomachs.
Consider Malate or Taurate: These other chelated forms are also well-tolerated and gentle on the gut, offering alternative benefits like energy support (malate) or heart health (taurate).
Take with Food: To reduce the risk of digestive irritation, always take magnesium supplements with food.
Start with a Low Dose: Begin with a smaller dose and increase gradually to allow your body to adjust and minimize side effects.
Try Topical Options: For extreme sensitivity, transdermal patches or creams allow magnesium absorption through the skin, bypassing the gut entirely.

Understanding Why Some Magnesium Supplements Cause Stomach Upset

Magnesium is an essential mineral involved in over 300 biochemical reactions in the body, including muscle function, nerve transmission, and energy production. However, many people experience gastrointestinal distress, such as diarrhea, nausea, and cramping, when taking certain magnesium supplements. This occurs because unabsorbed magnesium salts pull water into the intestines through osmosis, which increases bowel movements. The severity of this effect depends on two main factors:

The form of magnesium: Some forms are more soluble and bioavailable (more easily absorbed) than others. Poorly absorbed forms, like magnesium oxide, remain in the digestive tract and have a stronger laxative effect.
The dosage: Even the gentlest forms can cause digestive issues if taken in high doses. Starting with a low dose and increasing gradually can help minimize side effects.

The Top Contender: Magnesium Glycinate

For those with sensitive stomachs, magnesium glycinate is consistently recommended as the best option. It is a chelated form, meaning the magnesium is bound to the amino acid glycine. This chelation process greatly enhances its absorption in the small intestine, leaving less unabsorbed magnesium to cause a laxative effect. Magnesium glycinate is known for high bioavailability and is not commonly associated with diarrhea, making it a reliable choice for daily supplementation.

Other Gut-Friendly Magnesium Options

While glycinate is the top choice, other forms also offer good tolerability for sensitive individuals:

Magnesium Malate: Combining magnesium with malic acid, this form has a high absorption rate and is generally well-tolerated.
Magnesium Taurate: This highly bioavailable form binds magnesium with the amino acid taurine and is gentle on the stomach.
Magnesium Lactate: Known for being easy on the digestive tract, magnesium lactate is another suitable option for those with stomach sensitivity.

Forms of Magnesium to Avoid if You Have a Sensitive Stomach

It is best to avoid forms known for their laxative properties:

Magnesium Citrate: Has a natural laxative effect, increasing fluid in the bowel.
Magnesium Oxide: Poorly absorbed with a strong osmotic and laxative effect, typically used for short-term constipation or as an antacid.

Comparison of Common Magnesium Supplements


Feature	Magnesium Glycinate	Magnesium Malate	Magnesium Citrate	Magnesium Oxide
Best For	Relaxation, sleep, anxiety	Energy production, muscle function	Constipation relief	Short-term constipation, antacid
Digestive Impact	Very gentle, highly tolerable	Gentle, less likely to cause upset	Moderate to high laxative effect	Strong laxative effect
Bioavailability	High (bound to glycine)	High (bound to malic acid)	Moderate-High (bound to citric acid)	Low (poorly absorbed)
Cost	Generally higher	Moderate	Lower	Low

How to Minimize Digestive Side Effects

Here are some strategies to help minimize potential digestive issues:

Take with Food: Can help slow absorption and reduce the risk of upset stomach.
Split the Dose: Splitting your daily intake into smaller amounts at different times may help.
Start Low and Go Slow: Begin with a low dose and gradually increase it.
Stay Hydrated: Drinking plenty of water aids processing and absorption.
Consider Topical Application: For those who cannot tolerate oral supplements, topical options bypass the digestive system.

Conclusion

For those asking "which magnesium doesn't cause stomach upset," magnesium glycinate is the most reliable answer due to its superior bioavailability and gentleness. Magnesium malate and magnesium taurate are other well-tolerated options. Choosing a chelated form like glycinate and following best practices such as taking with food and starting with a low dose can help manage magnesium levels without discomfort. Consulting a healthcare professional is recommended before beginning a new regimen. For further information, consider reading resources from the National Institutes of Health. NIH Fact Sheet.

Frequently Asked Questions

Yes, certain types of magnesium, particularly those with low bioavailability like magnesium oxide and citrate, can cause digestive issues such as diarrhea, cramping, and nausea.

Magnesium glycinate is considered the most gentle and is highly recommended for individuals with sensitive stomachs due to its high absorption rate and low risk of causing digestive issues.

Magnesium oxide is poorly absorbed by the body. The unabsorbed magnesium salts remain in the intestine and draw water into the bowel, creating an osmotic effect that causes a laxative response.

Yes, magnesium malate is a chelated form that is generally well-tolerated and gentle on the stomach, making it a good option for those sensitive to other magnesium forms.

Yes, it is often recommended to take magnesium with food. This can help slow absorption and minimize the chances of experiencing nausea or diarrhea.

Topical magnesium, such as in creams, lotions, or sprays, can be an excellent alternative for those who cannot tolerate oral supplements. It allows magnesium to be absorbed through the skin, completely bypassing the digestive system.

If you experience symptoms like nausea, cramping, or loose stools after taking a magnesium supplement, it is a strong indication that the form or dosage is causing digestive upset. Try switching to a more gentle form like glycinate or lowering your dose.