Magnesium Forms Compared
Magnesium is a primary ingredient in some laxatives, and high doses of magnesium salts commonly cause diarrhea.[NIH Office of Dietary Supplements] Different forms are absorbed differently: one randomized study found magnesium citrate more bioavailable than oxide.[PubMed]
| Form | Score | Owner comments | Unwanted effects |
|---|---|---|---|
| Magnesium citrate | 4.0 | 843 | 6% |
| Magnesium oxide | 4.0 | 279 | 9% |
| Magnesium glycinate | 3.7 | 264 | 7% |
What owners report
In constipation communities, citrate and oxide are discussed mostly for their bowel effect, while glycinate is more often described as mild on the bowel and taken for other reasons. A 2021 placebo-controlled trial compared magnesium oxide with senna for chronic constipation.[PubMed]
Safety
- The NIH upper limit for magnesium from supplements is 350 mg a day for adults unless a doctor advises more, and people with kidney disease are at higher risk of magnesium build-up.[NIH Office of Dietary Supplements]
- Magnesium can reduce absorption of some antibiotics and osteoporosis drugs; space doses apart.[NIH Office of Dietary Supplements]
Compare: magnesium citrate vs oxide · citrate vs glycinate.
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