Supplements
magnesium treats chronic constipation
In plain terms: Does magnesium relieve constipation?
Part of: 🧪 magnesium
Yes—magnesium oxide is a genuine osmotic laxative with solid trial support, one of magnesium's best-established uses.
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
How the studies fall
What the evidence shows
Magnesium oxide is a genuine osmotic laxative and one of magnesium's best-supported uses: SR/MA and RCT evidence show it improves stool frequency/consistency in chronic idiopathic constipation, and it appears in dietary constipation guidance (albeit under-emphasized). This is a mechanism-backed, trial-supported effect — distinct from the softer supplement claims. measured_by:: [[chronic constipati
The evidence (4)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Morishita et al. 2021 · Am J Gastroenterol | RCT | supports | moderate | Double-blind placebo-controlled RCT: magnesium oxide effective vs placebo for chronic idiopathic constipation (compared against senna). |
| Dimidi et al. 2025 · J Hum Nutr Diet | observational | supports | low | BDA evidence-based dietary guideline: magnesium oxide among supported strategies for chronic constipation. |
| van der Schoot et al. 2023 · Neurogastroenterol Motil | meta-analysis | supports | moderate | SR/MA of food/vitamin/mineral supplements for chronic constipation: magnesium oxide effective for stool output/symptoms. |
| Dimidi 2025 · Proc Nutr Soc | observational | supports | low | Evidence review of dietary management of chronic constipation: MgO among strategies with supporting RCT/MA evidence, though under-recommended in guidelines. |
Disagree, or know a study we missed?
We grade by evidence, not opinions. The way to weigh in is to point us to a study we haven't cited (check the evidence table above first), or to flag a problem with one we have. Every submission is reviewed; if it holds up, the grade updates and shows in Science Changes Its Mind.
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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.