Which form of magnesium is best for diarrhea? An essential guide

November 13, 2025 •

4 min read

Up to 75% of people in the US may not get enough magnesium from their diet, but for those with sensitive stomachs, some supplements can cause unwanted side effects. This guide explains which form of magnesium is best for diarrhea to help you avoid digestive discomfort.

Quick Summary

Magnesium glycinate and other chelated forms are the best for avoiding diarrhea due to their high absorption. Laxative forms like citrate and oxide should be avoided by those with sensitive digestion.

Key Points

Magnesium Glycinate is the Best Choice: It is a chelated form with high absorption and a low risk of causing diarrhea, making it ideal for sensitive stomachs.
Avoid Laxative Forms like Citrate and Oxide: Magnesium citrate and magnesium oxide are commonly used to treat constipation and have a strong osmotic effect that can induce diarrhea.
Dosage Matters: High doses of any magnesium supplement can cause digestive issues, so starting with a low dose and increasing gradually is recommended.
Chelated Forms are Gentler: Look for chelated magnesium supplements, which are bound to amino acids for better absorption and less impact on the gut.
Take with Food: Consuming magnesium supplements with a meal can help reduce the likelihood of experiencing digestive discomfort.
Individuals with Kidney Issues Need Caution: Those with kidney problems should consult a doctor before taking magnesium, as excess levels can be dangerous.

Understanding the Cause of Magnesium-Induced Diarrhea

When you ingest magnesium, it attracts water into your intestines. This is known as an osmotic effect and is the same mechanism used by certain laxatives. For some forms of magnesium, especially those that are not well-absorbed, this effect can be particularly strong, leading to loose stools or full-blown diarrhea. The primary factors influencing this side effect are the specific form of magnesium and the dosage. Higher doses, regardless of the type, increase the likelihood of experiencing digestive upset.

The Best Forms of Magnesium for Avoiding Diarrhea

For individuals with a sensitive digestive system or those who have experienced diarrhea from other supplements, selecting a highly bioavailable, chelated form is the best strategy. These forms are bound to amino acids, which enhances absorption and reduces the osmotic effect in the gut.

Magnesium Glycinate

Why it's best: Magnesium glycinate is a chelated form bound to the amino acid glycine. It is widely recommended for its gentle effect on the stomach and high absorption rate. Its calming properties are often utilized for stress and sleep, making it a good multi-purpose choice.

Magnesium Malate

Why it's a good option: This form combines magnesium with malic acid, a compound found in fruits. It is also well-absorbed and reported by many users to be gentle on the stomach. Magnesium malate is sometimes favored for those seeking energy support.

Magnesium L-Threonate

Why it's also recommended: This specialized form is known for its ability to penetrate the blood-brain barrier and support cognitive health. It is considered a gentle option with a lower risk of causing digestive issues compared to laxative-prone forms.

Magnesium Taurate

Why it can be gentle: Bound to the amino acid taurine, this form is also known to be gentle on the digestive tract. It is often used to support cardiovascular health.

Forms of Magnesium to Avoid if You Have Diarrhea

If you have a history of digestive sensitivity or are specifically trying to avoid loose stools, these forms are generally not the right choice. They are effective as laxatives and can worsen diarrhea.

Magnesium Citrate

Why to avoid: Although highly bioavailable, magnesium citrate is also a powerful saline laxative due to its high solubility. It is commonly used to treat constipation or as a bowel prep for medical procedures.

Magnesium Oxide

Why to avoid: Despite its high elemental magnesium content, magnesium oxide has very poor bioavailability, meaning it is poorly absorbed. This low absorption, combined with its strong osmotic effect, makes it a potent laxative and an ingredient in products like Milk of Magnesia.

Magnesium Hydroxide

Why to avoid: This is the active ingredient in Milk of Magnesia and is specifically used as a laxative. It has a similar mechanism to magnesium oxide and should be avoided.

Magnesium Sulfate (Epsom Salt)

Why to avoid: When taken orally, magnesium sulfate is a powerful osmotic laxative used for colon cleansing. While often used topically for baths, consuming it is not recommended for those with or trying to avoid diarrhea.

Comparison Table: Magnesium Forms and Their Digestive Impact


Magnesium Form	Bioavailability	Likelihood of Causing Diarrhea	Primary Use	Best For
Glycinate	High	Low	Relaxation, sleep, deficiency	Sensitive stomachs
Malate	High	Low	Energy support, deficiency	Those seeking gentle options
L-Threonate	High	Low	Brain health, memory	Cognitive support without GI issues
Taurate	High	Low	Heart health, relaxation	Cardiovascular support
Citrate	High	High	Constipation relief, deficiency	Treating constipation
Oxide	Poor	High	Constipation, heartburn	Quick constipation relief
Hydroxide	Poor	High	Constipation, antacid	Immediate laxative effect

Tips for Supplementing Magnesium Without Digestive Distress

If you are prone to digestive issues, follow these best practices when taking magnesium:

Start with a lower dose. Begin with a small dose and slowly increase it to find your personal tolerance level.
Take it with food. Consuming your magnesium supplement with a meal can help minimize the risk of gastrointestinal side effects.
Consider a food-based source. Some people prefer to boost their magnesium intake through diet rather than supplements to avoid side effects.
Consult a healthcare provider. If you have a history of kidney disease, bowel disease, or take other medications, always speak with a doctor before starting a new supplement.

Conclusion: Making the Right Choice for Your Digestive Health

When choosing a magnesium supplement, the best form for diarrhea is one with high bioavailability that is gentle on the gastrointestinal tract. Magnesium glycinate stands out as a top contender for most individuals due to its excellent absorption and low laxative potential. Conversely, individuals should actively avoid forms like magnesium citrate and magnesium oxide, which are known to have a strong laxative effect. By understanding how different magnesium types affect the digestive system, you can choose a supplement that supports your health goals without causing unwanted discomfort. For more information, consult a reliable health resource such as Healthline on magnesium supplements and their benefits.

Lists

Magnesium-rich foods:
- Pumpkin seeds and almonds
- Spinach and leafy greens
- Black beans and legumes
- Avocado
Chelated magnesium forms:
- Magnesium glycinate
- Magnesium malate
- Magnesium taurate
Common magnesium side effects:
- Diarrhea
- Nausea
- Stomach cramps
- Muscle weakness (at very high doses)

Frequently Asked Questions

Magnesium glycinate is the form least likely to cause diarrhea. It is highly bioavailable, which means the body absorbs it more efficiently, resulting in less undigested magnesium causing an osmotic effect in the intestines.

Yes, high doses of any form of magnesium, even the gentler ones like glycinate, can cause diarrhea. The key is to find the right dosage and form that your body can tolerate without gastrointestinal distress.

For sensitive stomachs, magnesium citrate can be problematic. It is a known saline laxative that pulls water into the intestines, making it effective for constipation but potentially causing loose stools or diarrhea in those with digestive sensitivity.

To avoid digestive issues, start with a low dose of a chelated form like magnesium glycinate. Taking your supplement with food can also help minimize any gastrointestinal side effects.

Magnesium oxide causes diarrhea because it has poor absorption. As a result, much of it remains in the intestines, drawing water in through osmosis and causing a powerful laxative effect.

It is always best to prioritize getting nutrients from whole foods. Magnesium-rich foods include leafy greens, nuts, seeds, and legumes. A supplement is an option if your dietary intake is insufficient or a deficiency is identified.

You should consult a doctor if you experience severe or persistent diarrhea, if your symptoms are accompanied by fever, pain, or bleeding, or if you have pre-existing conditions like kidney disease. A healthcare provider can help determine the right magnesium approach for your needs.