Magnesium peroxide

MineralMagnesium compoundBest taken away from food

What is it

Magnesium peroxide (MgO2) is an inorganic compound that slowly releases oxygen when dissolved in water. It is used in colon cleansing supplements (marketed as 'oxygen-releasing colon cleansers') and in environmental remediation. It is not a typical magnesium supplement.

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Constipation (laxative effect)

Limited Evidence

Acts as an osmotic laxative similar to milk of magnesia. Effective for acute constipation.

Colon 'cleansing' / oxygenation

Mixed Evidence

Marketing claims about delivering oxygen to colon tissue are not supported by physiology; the effect is primarily a laxative one.

How it works

Magnesium peroxide decomposes in the acidic stomach environment, releasing oxygen and magnesium hydroxide (similar to milk of magnesia). The freed oxygen is the basis for marketing claims about oxygenating the colon. Magnesium hydroxide is a saline osmotic laxative that draws water into the bowel, causing soft stools and increased frequency. The 'oxygen cleanse' mechanism rests primarily on the laxative effect, not on tissue oxygenation.

Dosage

Commercial colon-cleanse products typically supply 500 mg to several grams of magnesium peroxide per dose.

When and how to take it

Used acutely for 'cleansing' rather than chronically. Typically taken on an empty stomach with abundant water.

1 commercial form

Compare the main delivery options and what they’re best suited for.

Magnesium peroxide capsules

Used in 'oxygen cleanse' colon-cleansing products.

Releases oxygen and magnesium hydroxide in acidic environment.

Safety

Can cause diarrhea, abdominal cramping, and electrolyte disturbances (especially hypermagnesemia) with high doses, particularly in people with kidney disease. Long-term laxative use can lead to dependence and electrolyte loss.

Who should be cautious

Avoid in people with kidney disease (risk of magnesium toxicity). Avoid in pregnancy and breastfeeding unless recommended by a clinician. Not for use in children without medical supervision. Not appropriate for chronic constipation management.

Interactions

May reduce absorption of medications taken concurrently due to laxative effect and pH changes. Caution with antibiotics, levothyroxine, and bisphosphonates. Magnesium can interfere with absorption of tetracyclines.

Frequently asked questions

Does magnesium peroxide really 'oxygenate' my colon?⌄

It releases oxygen in the gut, but this does not meaningfully oxygenate colon tissue. The clinical effect is laxative.

Is it safe?⌄

Acute use generally causes diarrhea. People with kidney disease should avoid it due to risk of magnesium accumulation.

Is it a good magnesium supplement?⌄

No. Choose conventional forms like magnesium citrate, glycinate, or oxide for nutritional supplementation. Magnesium peroxide is used for its laxative/oxygen-release property.

References

Magnesium peroxide on Wikidata — Wikidata link

Magnesium peroxide (ChEBI:81304) — ChEBI link

Magnesium peroxide (PubChem CID 61745) — PubChem link

Magnesium peroxide on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Magnesium peroxide (PubMed search) — PubMed link

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.