Magnesium citrate Side Effects: What Reddit Users Report
19 of 843 Reddit owner comments about Magnesium citrate (2%) describe an unwanted effect. The effects people mention most are nausea and constipation. These are self-reports from Reddit IBS and gut communities (November 2025 to October 2026), not a measured side-effect rate, and many people report no problems at all.
Magnesium citrate overall: 4.0 · tolerability 4.8 (higher means fewer unwanted-effect reports).
What people describe
| Effect mentioned | Owner comments |
|---|---|
| Nausea | 7 |
| Constipation | 4 |
How we counted: among the 19 comments that describe an unwanted effect, a category counts when a sentence names the effect with wording like "gave me" or "made me". Questions and sentences about an effect going away are skipped. One comment can count in more than one row, and keyword counts can include some unrelated mentions, so read the quotes below for context.
Most common complaints
- Side effects: 17 owner comments
- Urgency & loose stools: 7 owner comments
- Pain & cramping: 7 owner comments
Safety notes from NIH and published research
- The NIH upper limit for magnesium from supplements is 350 mg a day for adults unless a doctor advises more; the risk of magnesium toxicity rises with kidney disease.[NIH Office of Dietary Supplements]
- Magnesium can reduce absorption of some antibiotics (tetracyclines, quinolones) and osteoporosis drugs (bisphosphonates); space doses apart.[NIH Office of Dietary Supplements]
Stop and talk to a doctor if an effect is severe or does not settle. Ask a pharmacist about interactions with any medicine you take.
In their words
2/5 Side effects“If anything, they made me feel worse and I used to resort to drinking magnesium citrate (like the ones they give you for colonoscopy prep)”
2/5 Bloating & gasPain & cramping“I’d take bottle of mag citrate unless you are in severe pain with nausea, possible vomiting (especially stool), or can’t pass even gas.”
3/5 Side effectsTaste & texture“I'm not sure if this will help and disclaimer that I am absolutely not a doctor so please take this with a grain of salt, but when I had to have a partial colonoscopy, my doctor made me drink a whole bottle of magnesium citrate.”
2/5 Side effects“Magnesium citrate can also help since people use it to clear themselves out for colonoscopies.”
3/5 Side effects“It was always my last resort though after trying all the mirlax softeners ext I forgot about magnesium citrate or I would have taken that before the enemas.”
2/5 Side effects“I'm a bit hesitant to take mag citrate because of the possible side effects.”
2/5 Side effectsTaste & texture“Does it taste as bad as magnesium citrate (if you’ve had it to compare) I tried magnesium citrate but it literally made me so nauseous I couldn’t hold it down!”
3/5 Side effects“He said they exacerbate motility issues and that enemas plus magnesium citrate was better.”
Frequently asked
What side effects do people report with Magnesium citrate?
19 of 843 Reddit owner comments about Magnesium citrate (2%) describe an unwanted effect; the ones mentioned most were nausea and constipation. These are self-reports, not a measured side-effect rate.
Is Magnesium citrate safe?
Safety depends on your health and medicines. The NIH and other sources listed on this page note specific cautions. Ask a doctor or pharmacist before starting, especially if you take other medicines or are pregnant.
More on Magnesium citrate
Compare side-effect reports: Magnesium citrate vs Magnesium oxide · Magnesium citrate vs Magnesium glycinate · Psyllium husk vs Magnesium citrate