Why Does Magnesium Glycinate Hurt My Stomach?

November 24, 2025 •

3 min read

While magnesium glycinate is considered one of the most gentle and easily absorbed forms, some individuals still experience stomach upset. The reasons why does magnesium glycinate hurt my stomach can vary, from dosage issues to pre-existing digestive sensitivity.

Quick Summary

This article explores why magnesium glycinate can cause stomach pain, despite its mild reputation. Factors include dosage, absorption rate, and personal gut sensitivity. It offers strategies for minimizing discomfort.

Key Points

High Dosage: Exceeding the recommended dose, often over 350 mg, is a primary cause of stomach discomfort with any magnesium supplement, including glycinate.
Pre-existing GI Sensitivity: Individuals with sensitive digestive systems, like those with IBS, may experience irritation from any supplement, even gentle magnesium glycinate.
Take With Food: Consuming the supplement with a meal helps to buffer the stomach and reduce the likelihood of irritation, a simple but effective strategy.
Adjust Dosage Gradually: Starting with a low dose and slowly increasing it over time allows your body to acclimate and can prevent initial stomach upset.
Glycine's Potential Impact: While rare, the glycine molecule itself, especially in larger quantities, can sometimes contribute to mild digestive symptoms like bloating for sensitive individuals.
Magnesium's Relaxing Effect: In some cases, magnesium's muscle-relaxing properties can affect intestinal motility, leading to either constipation or loose stools and associated discomfort.
Product Formulation: Not all glycinate supplements are created equal; choosing a fully-reacted, high-quality product can ensure better absorption and fewer GI side effects.

Understanding the Gentle Nature of Magnesium Glycinate

Magnesium is an essential mineral involved in over 300 enzymatic reactions in the human body, supporting various functions from muscle and nerve health to blood glucose control. Different forms of magnesium supplements offer varying absorption rates and potential side effects. Magnesium glycinate, created by binding magnesium to the amino acid glycine, stands out for its high bioavailability and minimal impact on the digestive system. Unlike magnesium oxide, known for its poor absorption and laxative properties, the glycine in magnesium glycinate facilitates absorption and reduces the likelihood of diarrhea. However, even this gentle form can occasionally cause discomfort for some users.

Why Stomach Pain Can Still Occur with Glycinate

Despite its gentle nature, magnesium glycinate can still lead to gastrointestinal issues like cramps, nausea, or diarrhea. Several factors contribute to this:

High Dosage

Excessive dosage is a primary cause of stomach discomfort with any magnesium supplement. While the recommended daily intake for adults is typically between 310-420 mg, some supplements contain higher amounts. Doses exceeding 350 mg of elemental magnesium are more likely to cause side effects.

Individual Sensitivity and Underlying Conditions

Digestive responses to magnesium glycinate can vary significantly among individuals. Those with existing conditions like IBS or general gut sensitivity may be more susceptible to irritation, even from a gentle supplement.

The Glycine Factor

While glycine generally aids absorption and has calming properties, large amounts of any amino acid can sometimes affect digestion. The volume of the supplement, including glycine, might cause mild bloating or nausea in some individuals. Magnesium bisglycinate, with two glycine molecules, is sometimes better tolerated than glycinate with one.

Taking on an Empty Stomach

Taking supplements like magnesium on an empty stomach can irritate the stomach lining and cause discomfort. Consuming it with food can help mitigate this issue.

Strategies for Minimizing Discomfort

If you experience stomach pain from magnesium glycinate, consider these strategies:

Start with a lower dose: Gradually increase your intake to allow your body to adjust.
Take with food: Always consume your dose with a meal or snack to reduce stomach irritation.
Split the dose: Divide your daily dose into smaller portions taken throughout the day, especially for higher amounts.
Ensure adequate hydration: Staying well-hydrated can aid digestion.
Consider product quality: Choose a high-quality, fully reacted supplement to avoid potential issues from fillers or less absorbable forms.
Switch to bisglycinate: If using glycinate (one glycine molecule), trying bisglycinate (two glycine molecules) might improve tolerability.

Comparison of Common Magnesium Forms


Feature	Magnesium Glycinate	Magnesium Oxide	Magnesium Citrate
Absorption Rate	Very high, especially the bisglycinate form	Very low (approx. 4%)	High, but has a pronounced effect on the gut
Primary Use	Promoting relaxation, sleep, muscle function, reducing anxiety	Primarily for its laxative effect and heartburn relief	Addressing constipation, general magnesium supplementation
Risk of Stomach Upset	Low, due to chelation with glycine	High, frequently causes diarrhea, bloating, and cramps	High risk of laxative effect, may cause cramps
Gentleness	Very gentle, ideal for sensitive stomachs	Harsh on the digestive system	Can be harsh due to its osmotic effect

Conclusion

Magnesium glycinate is generally well-tolerated, but stomach pain can occur in a minority of users. This is often due to high doses, taking the supplement without food, or pre-existing digestive sensitivity. Implementing strategies like starting with a low dose, taking it with meals, and splitting the daily intake can help manage these issues. If discomfort continues, consult a healthcare professional to rule out other digestive concerns.

Additional Resources

For further information on magnesium supplementation and its effects, consult reputable medical sources. National Institutes of Health (NIH) - Magnesium Fact Sheet

Frequently Asked Questions

Magnesium glycinate is widely considered one of the best and gentlest forms for those with sensitive stomachs due to its high absorption and chelation with glycine, which prevents the laxative effect common with other forms.

Yes, for many individuals, taking magnesium glycinate on an empty stomach can increase the risk of nausea, stomach cramping, and general irritation. It is often recommended to take it with food to avoid this.

To minimize digestive side effects, it is best to start with a low dose (e.g., 100-200 mg) and gradually increase it. Most adults should not exceed 350 mg of supplemental magnesium per day unless advised by a healthcare provider.

If you experience consistent stomach issues with magnesium glycinate, even after adjusting dosage and timing, you may want to discuss alternative forms like magnesium malate or orotate with a healthcare provider. However, many find glycinate to be the best tolerated.

Magnesium glycinate is much gentler and less likely to cause diarrhea than magnesium citrate. Citrate has a strong osmotic effect, drawing water into the intestines, which is why it is often used as a laxative.

Yes, nausea can be a side effect, especially with high doses or when taken on an empty stomach. Taking it with food or splitting the dose can help reduce this symptom.

Magnesium bisglycinate, bound to two glycine molecules, is often marketed as being even more absorbable and gentler on the stomach than glycinate (one glycine molecule). For those sensitive to glycinate, bisglycinate may be a better option.