Magnesium glycinate vs citrate vs oxide
Short answer: NIH ODS says magnesium citrate, aspartate, lactate and chloride are absorbed more completely than magnesium oxide and sulfate. ODS does not assess magnesium glycinate separately. Whatever the form, the adult upper limit for magnesium from supplements and medicines is 350 mg a day.
| Form | What ODS says | Notes |
|---|---|---|
| Citrate | ODS: absorbed more completely than oxide (small studies). | Large doses can cause diarrhea. |
| Oxide | ODS: absorbed less well than citrate, aspartate, lactate and chloride. | One of the forms ODS lists as most often causing diarrhea. |
| Glycinate | Not assessed separately by ODS; we draw no conclusion. | The same UL applies: 350 mg/day of magnesium. |
Compare the milligrams of magnesium (elemental) on the label, not the weight of the whole compound. Our product pages and dose comparisons use elemental magnesium.
ODS lists magnesium carbonate, chloride, gluconate and oxide as the forms most often reported to cause diarrhea. Magnesium from food does not count toward the 350 mg limit.
Sources
This page only paraphrases the sources above and is not medical advice. If you are pregnant, breastfeeding, take medicines or have a chronic condition, ask a doctor or pharmacist first.