Magnesium oxide is one of the most affordable and widely available forms of magnesium, delivering a high concentration of elemental magnesium per dose. It’s commonly used to support digestive regularity, relieve occasional constipation, and may help reduce migraine frequency. While its bioavailability is lower than chelated forms like glycinate or citrate, magnesium oxide remains a go-to choice for targeted benefits at a budget-friendly price.
Quick Comparison
Product
Magnesium per Serving
Form
Best For
Rating
Nature Made Extra Strength Magnesium Oxide 400 mg
400 mg
Softgels
Best Overall
4.7/5
Mag-Ox 400
400 mg
Tablets
Best Pharmacist Recommended
4.6/5
NOW Magnesium Oxide Powder
290 mg elemental (500 mg oxide)
Powder
Best Powder
4.5/5
Nature Made Magnesium Oxide 250 mg
250 mg
Tablets
Best Budget Pick
4.7/5
Magnesium Oxide and Glycinate Extra Strength EasyMind
500 mg
Capsules
Best Combo Formula
4.4/5
Nature’s Bounty Magnesium 500 mg
500 mg
Tablets
Best High Dose
4.7/5
Triple Magnesium Softgels (Citrate, Malate & Oxide)
300 mg
Softgels
Best Multi-Form Blend
4.5/5
1. Nature Made Extra Strength Magnesium Oxide 400 mg – Best Overall
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Nature Made delivers a trusted, pharmacist-recommended magnesium oxide supplement at a dosage that meets most adults’ daily needs in a single softgel.
Each softgel provides 400 mg of magnesium oxide, which is the full recommended daily allowance for most adults. Nature Made is USP Verified, meaning the supplement has been independently tested for purity, potency, and quality. The softgel form is easier to swallow than standard tablets, and the formula is free of synthetic dyes, artificial flavors, and preservatives. A 110-count bottle offers nearly four months of daily use.
Pros:
USP Verified for purity and potency
One softgel per day for full daily dose
No synthetic dyes or artificial flavors
Cons:
Softgels are somewhat large
May cause digestive discomfort at full 400 mg dose
Best for: Anyone looking for a reliable, pharmacist-recommended daily magnesium oxide supplement
2. Mag-Ox 400 – Best Pharmacist Recommended
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Mag-Ox 400 is one of the most recognized magnesium oxide supplements on the market, long recommended by pharmacists for its concentrated formula.
Each tablet delivers 400 mg of magnesium from magnesium oxide, the most concentrated form of supplemental magnesium available. Mag-Ox supports over 300 biochemical reactions in the body, including muscle function, nerve signaling, and bone health. The formula is free of sugar, starch, and artificial colors. It’s manufactured in a GMP-compliant facility and has been a staple in pharmacies for decades.
Pros:
Pharmacist-recommended brand with long track record
High elemental magnesium per tablet
Free of sugar, starch, and artificial ingredients
Cons:
Tablet form can be harder to swallow than softgels
Higher price point compared to store brands
Best for: Those who want a pharmacy-grade magnesium oxide with a proven reputation
3. NOW Magnesium Oxide Powder – Best Powder
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NOW’s powder format makes it easy to customize your magnesium oxide dose, and it’s a standout option for migraine prevention support.
Each quarter-teaspoon serving provides 290 mg of elemental magnesium from 500 mg of magnesium oxide. The powder form allows flexible dosing — you can start low and work up as needed. NOW is GMP certified, and this product has been a favorite among migraine sufferers, with research supporting magnesium oxide at 400–500 mg daily for reducing migraine frequency. The powder mixes into water, juice, or smoothies.
Pros:
Flexible dosing with powder format
Research-backed for migraine prevention
GMP certified and affordable price per serving
Cons:
Taste and texture may be off-putting to some
Requires mixing into a beverage
Best for: Migraine sufferers and anyone who prefers customizable powder dosing
4. Nature Made Magnesium Oxide 250 mg – Best Budget Pick
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A lower-dose option from a trusted brand, ideal for those who want gentle magnesium oxide support without risking digestive side effects.
Each tablet provides 250 mg of magnesium oxide, making it a solid choice for adults who want to supplement without exceeding the tolerable upper intake. Like all Nature Made products, these tablets are USP Verified and free of gluten, synthetic dyes, and artificial flavors. The 100-count bottle provides over three months of daily use at a very low cost per serving.
Pros:
USP Verified for quality assurance
Lower dose reduces risk of GI side effects
Extremely affordable
Cons:
250 mg may not be enough for those with higher magnesium needs
Tablet form only
Best for: Budget-conscious shoppers who want a moderate daily magnesium dose
5. Magnesium Oxide and Glycinate Extra Strength EasyMind – Best Combo Formula
PureBotan Magnesium Oxide and Glycinate Extra Strength, Natural Sleep Aid Supplement EasyMind, High Absorption, Restful Sleep & Relaxation, Cortisol Lower, Natural-Gentle, Melatonin Free, 60 Capsules
Patented EasyMind Natural Sleep Aid: Patented EasyMind Blend combined with Magnesium oxide and glycinate help restful sleep and relaxation in natural & gentle. Help you fall asleep faster, stay asleep longer. Naturally provide deep sleep and calm, wake up refreshed, without melatonin
Gentle Stress Relief: The magnesium sleep aid supplement with Patented plant extract EasyMind, help gently relieve stress, promote the generation of positive emotions. Magnesium oxide and glycinate capsules promote muscle relaxation, provide physical relief from anxiety-related discomfort
More Magnesium & High Absorption: The magnesium oxide extra strength enables each capsule to contain Higher Magnesium Content. Magnesium glycinate optimizes absorption while being gentle on the stomach. Help you more fully replenish the magnesium your body craves
900mg Plant Extracts Per Capsule: The magnesium oxide and glycinate for sleep and anxiety, combined with Patented EasyMind, naturally provide deep sleep and calm. Our dual magnesium formula optimizes absorption and gentle on the stomach. These small magnesium capsules are easy to swallow
Pure & Natural: Our natural magnesium oxide and glycinate sleep aid supplement are gluten free, no preservatives, no artificial flavors. The Easymind magnesium oxide and glycinate capsules MADE IN THE USA, third-party tested for purity and safety
This dual-form supplement combines magnesium oxide with magnesium glycinate for both digestive and calming benefits in one capsule.
EasyMind pairs magnesium oxide (for its high elemental magnesium content) with magnesium glycinate (for its superior absorption and calming properties). This combination targets both regularity support and relaxation, making it a versatile option for sleep and stress. The extra-strength formula delivers 500 mg per serving in easy-to-swallow capsules, and it’s manufactured in a GMP-certified facility.
Pros:
Dual magnesium forms for absorption and potency
Supports both relaxation and digestive regularity
Extra-strength 500 mg dose
Cons:
Less established brand compared to Nature Made or NOW
Multiple capsules per serving
Best for: Those who want the benefits of both magnesium oxide and glycinate in one supplement
6. Nature’s Bounty Magnesium 500 mg – Best High Dose
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Nature’s Bounty delivers one of the highest magnesium oxide doses available in a single tablet, making it ideal for those with significant magnesium needs.
Each tablet provides 500 mg of magnesium from magnesium oxide, exceeding the daily recommended allowance in a single dose. Nature’s Bounty is a well-known supplement brand with decades of market presence. The tablets are free of artificial colors and flavors, and the 200-count bottle provides over six months of daily supplementation at an excellent value.
Pros:
High 500 mg dose per tablet
Exceptional value with 200-count bottle
Trusted brand with wide availability
Cons:
High dose may cause laxative effects
Large tablet size
Best for: Those directed by a healthcare provider to take higher-dose magnesium supplementation
7. Vital Nutrients Triple Magnesium Complex – Best Premium
Vital Nutrients Triple Magnesium Complex Supplement | Vegan Magnesium Glycinate, Malate & Oxide 250mg | Easily Absorbed Magnesium Supplement for Stress, Muscle, Heart, Bone Support | 90 Capsules
Premium Vegan Magnesium Supplement: The powerful formula in Triple Magnesium Complex combines three synergistic forms of magnesium to support sleep, stress relief, bone, heart, muscle, and neurological health and promote relaxation. Magnesium is needed for more than 600 body processes and supports healthy stress responses*
Easy-Absorption Combination Formula for Less GI Discomfort: Magnesium blend supplement designed for maximize absorption and minimize GI discomfort with our potent blend featuring 250mg of magnesium in three bioavailable forms: magnesium glycinate, dimagnesium malate, and magnesium oxide. Tri Magnesium Supplement formulated for full absorption and to be gentle on your stomach*
Clean Vegan Formula. Hypoallergenic and Non-GMO. Made without artificial fillers, coatings, binders, or colors.
Quality You Can Rely on: Our rigorous quality assurance program includes third-party independent laboratory testing of raw ingredients and finished products for purity and potency to ensure what’s on the label is in the bottle.
Trusted by Healthcare Practitioners Worldwide: Vital Nutrients was founded 30 years ago by practitioners who set out to make a positive and lasting impact on the health of people and planet. Today, our premium line of clinically relevant, pure, clean-label formulas is trusted by healthcare practitioners and health-conscious consumers worldwide
Vital Nutrients combines magnesium glycinate, malate, and oxide in a practitioner-grade formula designed for superior absorption and broad-spectrum support.
This triple magnesium complex blends three forms of magnesium — glycinate for calming support, malate for energy production, and oxide for elemental potency. Vital Nutrients is a practitioner-trusted brand that third-party tests every batch for purity, potency, and contaminants. The vegan capsules are free of major allergens and manufactured in a GMP-compliant facility. It’s a premium option for those who want magnesium oxide as part of a comprehensive magnesium blend.
Pros:
Three forms of magnesium for diverse benefits
Third-party tested and practitioner-grade quality
Vegan and allergen-free
Cons:
Higher price than single-form magnesium supplements
Requires multiple capsules per serving
Best for: Those who want a premium, multi-form magnesium supplement that includes oxide
8. Triple Magnesium Softgels (Citrate, Malate & Oxide) – Best Multi-Form Blend
These softgels deliver three highly complementary forms of magnesium in an easy-to-absorb softgel format for well-rounded mineral support.
Each serving combines magnesium citrate, malate, and oxide to cover multiple health benefits — from digestive regularity (oxide and citrate) to energy metabolism (malate). The softgel format enhances absorption compared to standard tablets, and the formula provides 300 mg of total elemental magnesium per serving. It’s a great middle-ground option for those who want the potency of oxide with the absorption advantages of chelated forms.
Pros:
Three complementary magnesium forms
Softgel format for easier swallowing and absorption
Balanced 300 mg dose
Cons:
Not a pure magnesium oxide product
Smaller brand with fewer reviews
Best for: Those who prefer a blended magnesium formula with oxide included in softgel form
How to Choose the Best Magnesium Oxide Supplement
Magnesium oxide contains the highest percentage of elemental magnesium by weight (about 60%) of any supplemental form, which is why it remains popular despite lower bioavailability compared to chelated forms like glycinate or citrate. If your primary goal is digestive regularity, occasional constipation relief, or migraine prevention support, magnesium oxide is a well-studied and cost-effective choice.
When selecting a magnesium oxide supplement, pay attention to the elemental magnesium content per serving — not just the total compound weight. Most adults need 300–420 mg of magnesium daily, and many magnesium oxide products deliver this in a single dose. Start with a lower dose (250 mg) and work up if needed, as higher doses can cause loose stools or digestive discomfort.
Choose products from brands that undergo third-party testing or carry certifications like USP Verification or GMP compliance. These ensure the supplement contains what the label claims without harmful contaminants. Nature Made, NOW, and Vital Nutrients all meet these quality benchmarks.
Form matters as well. Softgels tend to be easier to swallow and may absorb slightly faster than compressed tablets. Powder gives you the most dosing flexibility. If you want the potency of oxide plus the absorption benefits of other forms, consider a multi-form magnesium complex that includes oxide as one of the ingredients.
Frequently Asked Questions
What is magnesium oxide and what does it do?
Magnesium oxide is a mineral supplement that provides a high concentration of elemental magnesium. It supports muscle and nerve function, bone health, heart rhythm, and digestive regularity. It’s also commonly used as an osmotic laxative and has been studied for migraine prevention.
How much magnesium oxide should I take daily?
Most adults benefit from 250–400 mg of magnesium oxide daily. The Recommended Dietary Allowance for magnesium is 310–320 mg for women and 400–420 mg for men. The tolerable upper intake from supplements is 350 mg per day, though some products exceed this — consult a healthcare provider for personalized guidance.
When is the best time to take magnesium oxide?
Magnesium oxide can be taken at any time of day, ideally with food to minimize stomach upset. If you’re taking it for sleep or relaxation support, evening dosing is common. For constipation relief, take it with a full glass of water.
Are there any side effects of magnesium oxide?
The most common side effect is digestive discomfort, including loose stools, diarrhea, or stomach cramping — especially at higher doses. Magnesium oxide has a well-known laxative effect due to its osmotic action in the intestines. Starting with a lower dose and increasing gradually can help minimize these effects.
Can I take magnesium oxide with other supplements?
Magnesium oxide is generally safe to combine with most other supplements. However, it can interfere with the absorption of certain medications, including antibiotics and bisphosphonates. Take magnesium oxide at least two hours apart from these medications. It pairs well with vitamin D, which can enhance magnesium absorption.
How long does it take for magnesium oxide to work?
For constipation relief, magnesium oxide typically works within 30 minutes to 6 hours. For benefits like migraine prevention or general health support, consistent daily use for 4–12 weeks is usually needed to see noticeable results.