Is 500mg of magnesium too much?

500mg of what, against which level, and the elemental answer first

Is 500mg of magnesium too much depends on two things the question leaves out, 500mg of what and against which level, and the variants this query carries, 300mg, 400mg, 500mg of glycinate, 1500mg of glycinate, are all answered by the same two. The level is the UK expert group's supplemental guidance of about 400mg of magnesium a day from supplements, a level below which long-term intake is not expected to cause adverse effects in healthy adults, with the practical ceiling arriving earlier as the osmotic laxative effect and the one real danger, accumulation, confined to impaired kidneys. The unit is elemental or compound, the label guide's standing distinction, and the %NRV line on any tub settles it. The elemental answer first: 500mg of elemental magnesium a day from a supplement is over the 400mg guidance level, and what that means is precise, that loose stools are likely at that dose for most people, worst as oxide and least as bisglycinate, that harm is unlikely in a healthy adult whose kidneys excrete the surplus, the long-term trials at 500mg in older adults having reported no serious effects, and that no benefit accrues over 300mg for a lifter whose shortfall 300mg already closes, so 500mg elemental is too much in the sense of being surplus and laxative and not in the sense of being dangerous, with kidney disease turning it into a genuine risk. 400mg elemental sits at the level, the top of the range rather than over it, and 300mg elemental sits under it with room, the section's standing dose at 80% of the NRV.

The compound answers, the matrix that covers every variant, and the number filed

The compound answers reverse the picture. 500mg of magnesium glycinate is a compound weight, and at the commercial 20% figure it contains about 100mg of elemental magnesium, roughly 27% NRV, a modest dose that is nowhere near too much and is, for a lifter meaning to take a reference-value amount, too little, the 500mg-glycinate template's reading; at the pure chelate's 14% it is about 70mg. 1500mg of magnesium glycinate contains about 300mg elemental at 20%, the worked example's exact specification, under the level and the section's recommendation. 400mg of magnesium glycinate is about 80mg elemental, fine and small, and 400mg elemental as glycinate is about 2000mg of compound, three to four capsules, at the level. 1000mg of glycinate is about 200mg elemental, fine. The matrix that covers every variant runs on those two axes: read the unit from the %NRV, 80% meaning 300mg elemental and about 27% meaning 500mg of compound, then place the elemental figure against 400mg, under it fine, at it the top, over it surplus and laxative and, only in kidney disease, dangerous. The number filed: 500mg of elemental magnesium is over the guidance level and too much in the surplus-and-laxative sense, 500mg of magnesium glycinate is about 100mg elemental and fine, 1500mg of glycinate is the section's 300mg, 300mg elemental is the dose and 400mg is the ceiling, with the worked example printing both units so that the question answers itself on the label, 1500mg bisglycinate giving 300mg elemental at 80% NRV, £19.99 for 90 days at 22p.

The verdict, too much only as elemental and only as surplus

Is 500mg of magnesium too much: as elemental magnesium, yes in the surplus sense, over the 400mg UK supplemental guidance level, likely laxative and unlikely to harm a healthy adult while adding nothing over 300mg, and dangerous only in kidney disease; as 500mg of magnesium glycinate, no, about 100mg elemental and modest; with 1500mg of glycinate being the section's 300mg, 300mg elemental the dose and 400mg elemental the ceiling, the %NRV line on any tub telling which unit the front means. Both units printed: Futuro Labs Magnesium Glycinate, 1500mg bisglycinate giving 300mg elemental at 80% NRV, £19.99 for 90 days at 22p a day.

What to check on the label

Questions people also ask

Is 500mg of magnesium per day too much?

As elemental magnesium, it is over the UK supplemental guidance level of about 400mg, likely to loosen stools and unlikely to harm a healthy adult whose kidneys excrete the surplus, while adding nothing over 300mg; as 500mg of magnesium glycinate it is about 100mg elemental and fine.

Is 500mg of magnesium glycinate too much daily?

No: 500mg of the compound is about 100mg of elemental magnesium at the commercial 20% figure, roughly 27% NRV, a modest dose that is, for a lifter meaning to take a reference-value amount, on the small side.

Is 1500mg of magnesium glycinate too much?

No: 1500mg of bisglycinate is about 300mg of elemental magnesium, 80% NRV, under the 400mg guidance level and the section's standing dose, the worked example's exact specification over two capsules.

Is 400mg of magnesium too much?

As elemental magnesium it sits at the guidance level, the top of the range rather than over it, and as 400mg of glycinate it is about 80mg elemental, small; 300mg elemental is the dose with room under the level.

When is a high magnesium dose actually dangerous?

Only with impaired kidneys: chronic kidney disease lets magnesium accumulate to hypermagnesaemia, so any dose there is a doctor's decision, while a healthy adult over the level meets the laxative effect and nothing worse.

Sources

1. Expert Group on Vitamins and Minerals. Safe Upper Levels for Vitamins and Minerals. Food Standards Agency, 2003 (magnesium guidance level 400mg a day from supplements). https://cot.food.gov.uk/sites/default/files/vitmin2003.pdf
2. Retained Regulation (EU) No 1169/2011, Annex XIII: nutrient reference value for magnesium 375mg. https://www.legislation.gov.uk/eur/2011/1169/annex/XIII
3. The magnesium bisglycinate chemistry: the pure chelate, one magnesium to two glycine, is about 14% magnesium by weight, and commercial bisglycinate ingredients, buffered or of different chelate ratios, declare magnesium contents up to about 20%. PubMed record
4. The hypermagnesaemia literature: the kidneys excrete surplus magnesium, so supplementation is safe for healthy adults within guidance and warrants medical advice in chronic kidney disease, where impaired excretion allows magnesium to accumulate. PubMed record

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