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Magnesium Oxide Supplement


Magnesium Oxide supplement from Cooper Complete helps support:

  • Bone health
  • Energy production
  • Heart health
  • Sleep health
  • 1 capsule per serving. 100 capsules per bottle.

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Product Details

Product Description

Magnesium Oxide is involved in more than 600 biochemical reactions in the human body. Every cell in your body contains it and needs it to function.

Bone Health:

  • Magnesium Oxide works with vitamin D and calcium to create a strong structure for bones
  • Calcium levels in the bones are regulated by magnesium

Energy Production:

  • Magnesium Oxide helps convert food, especially carbs, into energy for the body
  • Low magnesium levels lead to insulin resistance which leads to fatigue

Heart Health:

  • American Heart Association found an association between low magnesium levels and increased rates of mortality
  • Magnesium Oxide helps protect blood vessels by helping them relax and pump at a lower pressure

Sleep Health

  • Magnesium Oxide helps regulate the hormone melatonin to promote healthy sleep cycles
  • Healthy magnesium levels help stimulate calming signals in the nervous system

Cooper Complete products are verified and lot tested. If you would like a copy of a Certificate of Authenticity for a specific product or would like to learn more about our testing process and results, please contact us at  or call our team directly at 888.393.2221 9 a.m. until 5 p.m. Monday-Friday central time (CST).

Supplement Facts
Serving Size: 1 capsule
Servings Per Container: 100
% Daily
Magnesium (from 500 mg Magnesium Oxide)300 mg75%

Other ingredients: Hydroxypropyl methylcellulose (capsule), microcrystalline cellulose, carnauba wax, ascorbyl palmitate, hydroxypropyl cellulose and silica.

Gluten-Free, Non-GMO

While we strive to ensure the label information on this site represents the label on the product available for purchase, products are updated from time to time. Please consult the label on the product you purchase for the most accurate ingredient and allergen information.

Item Number: 166
SKU: 816899000614
Formula Number: 202434-100-PL-84121312
Product of USA


Frequently Asked Questions

What is Magnesium Oxide?

Magnesium oxide (MgO) is an inorganic compound that occurs in nature as the mineral periclase. It is the oxide salt of magnesium. In addition to its benefits for bone health, energy production and heart health, it is also often used as an antacid and mild laxative and has many nonmedicinal uses.

Does Magnesium Oxide have a laxative effect?

A common complaint about magnesium is the laxative qualities of magnesium so we suggest that you start with one pill, and increase as needed from there. Taking magnesium with food can reduce the occurrence of diarrhea. Magnesium Glycinate should be considered if diarrhea or other gastrointestinal distress occurs.

What foods contain magnesium?

Good food sources of magnesium include leafy vegetables, whole grains, bananas, nuts, seeds and legumes. Water can also contain magnesium but the amount of magnesium can vary widely. Food processing erodes magnesium in foods. Despite the prevalence of magnesium in food, US dietary surveys typically find magnesium intake less than recommended.

How much magnesium should I take per day?

The Recommended Dietary Allowance (RDA) for magnesium varies by age and gender. Adult women need 310-360 mg per day while adult men need 400-420 mg. Since health conditions and illnesses can impact the amount of magnesium needed, it’s important to speak with your physician to understand your specific needs.

How much elemental magnesium is in each capsule?

Each Cooper Complete Magnesium Oxide capsule provides 300 mg elemental magnesium.

When should I take Magnesium Oxide?

We suggest magnesium supplements be taken with your evening meal. Magnesium supplements should not be taken within two (2) hours of the osteoporosis medication Fosamax. Many antibiotics should be taken at least 2 hours before or 4-6 hours after a magnesium supplement.

What are signs of magnesium deficiency?

Magnesium deficiency can contribute to muscle spasms, osteoporosis, fibromyalgia, arrhythmia (AFIB) and migraines.

What are magnesium deficiency risk factors?

Older adults, people with diseases of malabsorption such as Crohn’s disease and celiac disease, type 2 diabetics, and alcoholics are all at risk of magnesium deficiency. Long time use of prescription diuretics can increase magnesium loss in urine and deplete magnesium levels.

Should I take calcium with magnesium?

Calcium and magnesium have a complicated relationship. Magnesium is essential for the absorption and metabolism of calcium inside the body. It’s important to keep these two minerals in balance. Too much calcium and/or too little magnesium can have negative health effects. It is important to speak with your physician before taking supplements to understand your specific needs.

Has magnesium oxide been widely studied?

Yes. PubMed Central (PMC) has thousands of research articles on magnesium oxide.