What is the other name for magnesium oxide 400mg?

November 26, 2025 •

3 min read

According to Drugs.com, magnesium oxide is sold under several brand names, including Mag-Ox 400. Therefore, another common name for magnesium oxide 400mg is Mag-Ox 400, though other names like Uro-Mag are also used for varying dosages.

Quick Summary

This article discusses the various brand names and alternative monikers for magnesium oxide 400mg, including Mag-Ox 400 and Uro-Mag, and explores its common medical uses as an over-the-counter supplement.

Key Points

Brand Name: The most common brand name for magnesium oxide 400mg is Mag-Ox 400, though others like Uro-Mag also exist.
Alternate Generic Name: Magnesium oxide is also known by its chemical synonym, magnesia.
Dual Function: It acts as both an antacid and a laxative, with its primary function often depending on the dosage and individual needs.
Low Bioavailability: Due to its poor absorption rate, magnesium oxide is not the best choice for treating magnesium deficiency but is effective for digestive issues.
Kidney Health: Individuals with kidney problems should use caution, as high doses can lead to hypermagnesemia, a dangerous condition.
Medication Interference: It can block the absorption of certain medications, so it should be taken at least two hours apart from other drugs.

Common Brand and Trade Names for Magnesium Oxide 400mg

While the chemical name for this compound is magnesium oxide, it is widely recognized and sold under several different brand and trade names, particularly for the 400mg dosage. The most prominent alternative name for magnesium oxide 400mg is Mag-Ox 400. It is crucial for consumers to understand these different names to ensure they are purchasing the correct medication or supplement.

Other notable brand names that contain magnesium oxide in various strengths, including those that might offer a 400mg equivalent, include:

Mag-Oxide
Uro-Mag
Mag-200
Mag-Caps
Maox

Beyond brand names, the chemical compound itself is also known by alternative names. The mineral form of magnesium oxide that occurs naturally is called periclase. Historically, it was also referred to as magnesia. These names are more common in chemical or geological contexts, but understanding them can help distinguish the generic substance from branded products.

The Dual Role of Magnesium Oxide in Medicine

Magnesium oxide is a versatile over-the-counter (OTC) product used for different purposes depending on the dosage. Its low bioavailability, meaning the body does not readily absorb it into the bloodstream, is the reason for its dual function.

Antacid: As an antacid, magnesium oxide helps relieve symptoms of indigestion, heartburn, and sour stomach by neutralizing stomach acid. For this use, the 400mg dose might be taken once or twice daily, but generally not for extended periods.
Laxative: In higher doses, magnesium oxide draws water into the intestines through an osmotic effect, helping to soften stool and promote bowel movements. This makes it an effective, albeit temporary, treatment for constipation.

Comparison of Magnesium Oxide vs. Other Magnesium Forms

When considering a magnesium supplement, it's important to understand how magnesium oxide compares to other forms, such as magnesium citrate, due to differences in bioavailability and purpose.


Feature	Magnesium Oxide	Magnesium Citrate
Bioavailability	Low; a high percentage is not absorbed by the body.	High; absorbed easily and effectively by the body.
Primary Uses	Antacid, laxative, and general supplement. Often used for short-term digestive issues.	Dietary supplement to correct magnesium deficiency. Can also be used as a laxative.
Elemental Magnesium	High elemental magnesium content per milligram of compound.	Lower elemental magnesium content per milligram compared to oxide.
Digestive Effects	Can have a strong laxative effect, often leading to diarrhea due to low absorption.	Generally gentler on the digestive system, but can still be a laxative.

Key Considerations When Taking Magnesium Oxide

Individuals should be aware of several factors before taking any magnesium oxide supplement, including the 400mg dose. It is always recommended to consult a healthcare professional before starting any new supplement regimen.

Kidney Function: Individuals with impaired kidney function are at a higher risk of developing hypermagnesemia (high magnesium levels in the blood), which can be dangerous.
Interactions: Magnesium oxide can interfere with the absorption of certain antibiotics (like tetracyclines) and other medications, so it's best to take them at least two hours apart.
Long-Term Use: For chronic conditions or supplementation, a more bioavailable form of magnesium might be more effective. Magnesium oxide is generally not recommended for long-term daily use without medical supervision.

Dosage and Purpose

For specific conditions, magnesium oxide is dosed differently. For example, for migraine prevention, daily doses of 400-600 mg are often recommended. For constipation, higher doses, often over 1 gram, might be used. A 400mg dose is a common over-the-counter strength, and its purpose will depend on the brand and specific medical advice. For instance, some may use the 400mg tablet for general supplementation, while others use a higher dose for a laxative effect.

Conclusion

The other names for magnesium oxide 400mg are primarily its brand names, with Mag-Ox 400 being the most common. Other brand and generic names exist, such as Uro-Mag and magnesia. This form of magnesium is particularly useful as a laxative and antacid due to its low absorption rate, but it is less effective for raising systemic magnesium levels compared to more bioavailable forms. A 400mg dosage can serve different purposes, but users should always consider their specific health needs, kidney function, and potential drug interactions, and should consult a healthcare provider for personalized advice.

For more comprehensive information on medications, including magnesium oxide, visit Drugs.com.

Frequently Asked Questions

The most common brand name for magnesium oxide 400mg is Mag-Ox 400. Other brands like Uro-Mag also produce tablets containing magnesium oxide.

Yes, magnesia is another name for the chemical compound magnesium oxide. This name is more common in chemical contexts, while magnesium oxide is the standard generic name for supplements.

Magnesium oxide 400mg is commonly used as a dietary supplement to address low magnesium levels, as an antacid to relieve heartburn, and as a laxative to treat constipation.

Magnesium oxide has a lower bioavailability than magnesium citrate, meaning the body absorbs it less effectively. This makes citrate a better choice for raising overall magnesium levels, while oxide is more potent as a laxative due to its poor absorption.

While it can be used for daily supplementation, it is not the most effective form for increasing blood magnesium levels due to low absorption. For long-term use, especially for deficiency, a different form of magnesium might be more suitable.

Common side effects include digestive issues such as diarrhea, upset stomach, and bloating. In high doses or in individuals with kidney problems, it can lead to dangerous levels of magnesium in the blood (hypermagnesemia).

Yes, other brand names that contain magnesium oxide include Uro-Mag, Mag-Caps, and Mag-Oxide, though the specific dosage may vary by product.