Why magnesium matters

Magnesium is an essential mineral your body uses in hundreds of chemical reactions: energy production, muscle and nerve function, blood pressure control, bone health and more. Many adults don’t get the recommended amounts from food alone (about 420 mg/day for men and 320 mg/day for women), so supplements are commonly used to help reach healthy levels. Different forms of magnesium behave differently in the body — the two most commonly compared are magnesium citrate and magnesium glycinate (often called bisglycinate). Choosing between them depends on your goals, tolerance and budget.

What is magnesium citrate?

Magnesium citrate is magnesium paired with citric acid. It’s well absorbed by the body and is widely available and affordable. At low to moderate doses it’s an effective way to raise magnesium intake. At higher doses, however, citrate can draw water into the gut and have a laxative effect — some people use this intentionally to relieve constipation. For people who are sensitive to stomach upset or worry about loose stools, citrate is more likely to cause that than some other forms.

Pros

• Good absorption for many people

• Readily available and budget-friendly

• Useful if occasional laxative effect is desirable

Cons

• More likely to cause loose stools or diarrhea at higher doses

• May be less comfortable for people with sensitive digestion

What is magnesium glycinate (bisglycinate)?

Magnesium glycinate is magnesium bound to the amino acid glycine. It’s a “chelated” form, which tends to be gentle on the stomach and less likely to cause diarrhea. Because it’s well tolerated, it’s often recommended when the goal is to raise body magnesium stores without disturbing bowel habits. Some people also notice a calming effect from the glycine component, and it’s commonly used in evening routines, though individual results vary.

Pros

• Gentle on the stomach and rarely causes laxative effects

• Good option for maintaining levels long term

• Often better tolerated at higher doses

Cons

• Typically more expensive than citrate

• Slightly higher cost per milligram of magnesium

How to choose between citrate and glycinate

• If your main priority is tolerability and you want to raise magnesium stores without changing bowel habits, magnesium glycinate (bisglycinate) is a strong choice.

• If you want the most value for money and don’t mind or want a mild laxative effect, magnesium citrate is a reasonable option.

• If you have constipation and would welcome a laxative effect, citrate (or oxide in some cases) can be useful — but expect more GI upset.

• If your primary concern is cognition or sleep, some people choose magnesium L‑threonate for its brain‑focused profile. L‑threonate is more expensive and usually provides less elemental magnesium, so it may be less effective to correct whole‑body magnesium deficiency.

Practical dosing and what to look for

• Look at the label for “elemental magnesium.” Different compounds contain different amounts of elemental magnesium per dose, so the label is the only reliable guide to how much magnesium you’re actually getting.

• Aim to supplement in the context of a magnesium‑rich diet. For many people who eat a plant‑based, whole‑food diet, a supplemental dose in the 300–350 mg range of elemental magnesium is often sufficient.

• The generally recommended daily allowances are about 420 mg for adult men and 320 mg for adult women. Those are total intake targets from food plus supplements.

• There’s a recommended upper limit for magnesium from supplements (not food), so don’t assume “more is better.” Unless directed by a clinician, avoid routinely exceeding commonly advised supplemental limits.

• Start low and increase gradually. If you experience loose stools with citrate, lower the dose or switch to glycinate.

Timing

• Magnesium can be taken with or without food; taking it with a meal often reduces the chance of stomach upset.

• Magnesium can interfere with absorption of some medications (for example certain antibiotics and osteoporosis drugs). Space magnesium supplements and these medicines by a couple of hours, and check with your clinician or pharmacist for specific guidance.

• People with impaired kidney function should consult a clinician before taking magnesium supplements, because the kidneys are the main route for removing excess magnesium.

Side effects and safety

• The most common side effects are gastrointestinal: loose stools, cramping or mild stomach upset. These are more common with citrate, magnesium oxide and higher doses.

• In people with healthy kidney function, serious magnesium toxicity is rare. But in those with kidney disease or when very large doses are taken, elevated magnesium can cause symptoms that require medical attention.

• If you are pregnant, breastfeeding, have a chronic condition or take multiple medications, check with your healthcare provider before starting a supplement.

Putting it into practice

• For everyday maintenance without bowel effects: magnesium glycinate (bisglycinate) or magnesium chloride are generally well tolerated and effective.

• For cost-conscious supplementation that’s well absorbed: magnesium citrate is a practical option, but be mindful of bowel tolerance.

• If targeting sleep or cognitive effects and willing to pay more: magnesium L‑threonate is an option, though it usually provides smaller amounts of elemental magnesium.

• Always check the supplement label for elemental magnesium, consider third‑party testing, and aim to fill gaps on top of a magnesium‑rich diet rather than replacing healthy eating.

Conclusion

Both magnesium citrate and glycinate can raise magnesium intake effectively. Choose glycinate (bisglycinate) when you want a gentle, well‑tolerated option to maintain or build body magnesium stores. Choose citrate when you want an affordable, well‑absorbed form and don’t mind—or may even want—the occasional laxative effect. Match your choice to your goals, check the elemental magnesium on the label, start with a conservative dose, and consult your healthcare provider if you have kidney disease, take interacting medications, or have other health concerns.

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