Does magnesium glycinate cause stomach upset?

Two guts, the stomach's complaint within an hour and its causes and fix

Does magnesium glycinate cause stomach upset is answered rarely, and the honest sort is by which gut is complaining, because stomach upset covers two things with different causes, different timings and different fixes. The stomach's complaint arrives within an hour of the capsule: nausea, a queasy or heavy feeling, occasionally a burp or a reflux, and it has three causes. A fasted capsule: any mineral salt in an empty stomach is more likely to nauseate than the same salt with food, the ZMA pages' fasted-zinc finding applying in a milder form to magnesium, and a reader who takes their glycinate on waking with water and feels queasy at the desk has met it. A large capsule: some glycinate products are single large capsules or tablets carrying a full dose, and a big object landing in an empty stomach produces the heavy feeling on its own, the gelatin or HPMC shell dissolving in minutes but the mass of compound, one and a half grams for 300mg of magnesium, sitting until it dissolves. A sensitive stomach: a reader with reflux, gastritis or simply a stomach that objects to supplements objects to this one too, magnesium being neither acidic nor irritant but the capsule being a capsule. The fix for all three is the same: take it with a meal, the with-food page's finding that food helps absorption rather than hurting it, and split the dose across two meals so that each capsule is smaller and each sitting lighter, the morning-and-night pattern, a reader who cannot tolerate any capsule opening it into yoghurt or a smoothie, which removes the object and keeps the dose.

The bowel's complaint at six to twelve hours, the product that causes both, when it is not the magnesium, and the sort filed

The bowel's complaint arrives at six to twelve hours, when the unabsorbed remainder of a dose reaches the colon and draws water: loose stools, griping, urgency, and it is the remainder arithmetic, the effect scaling with what the gut did not absorb, which for bisglycinate at a labelled dose under the guidance level is little, the chelate absorbed well and proposed to travel partly intact, so that pure glycinate loosens few people and a nightly habit stays out of the bathroom, the laxative-effect page's finding. When bisglycinate does loosen, the cause is one of two: a dose well over the 400mg level, where absorption saturates and the remainder grows, fixed by returning to a labelled dose and splitting it; or a product that is not pure bisglycinate, the tub sold under the glycinate name whose ingredients list reads bisglycinate then oxide and whose oxide half behaves like oxide, poorly absorbed, heavily laxative and, being a large dose of an insoluble salt in the stomach, nauseating too, the one product that causes both guts' complaints at once, fixed by the ingredients list and a pure bisglycinate with no oxide in it. When it is not the magnesium at all: a new supplement started in the same week as a new protein powder, a new pre-workout, a diet change or an antibiotic course gets the blame for what the other thing did, and a stomach upset that persists after the capsule is stopped for a week has another cause and a GP, with persistent nausea, vomiting, black stools, blood or weight loss going to a GP whatever the capsule. The sort filed: the stomach's nausea within an hour from a fasted or large capsule, fixed by a meal and a split; the bowel's loose stools at six to twelve hours from a dose over the level or an oxide-buffered product, fixed by the dose and the ingredients list; and neither from pure bisglycinate at a labelled dose with a meal in most people, the worked example being pure bisglycinate in two small capsules with no oxide in the list, £19.99 for 90 days at 22p.

The verdict, rarely, and sorted by which gut and which hour

Does magnesium glycinate cause stomach upset: rarely, and the complaint sorts by gut and by hour, the stomach's nausea, queasiness or heaviness within an hour coming from a fasted capsule, a large one or a sensitive stomach and fixed by a meal, a split or a capsule opened into food, and the bowel's loose stools or griping at six to twelve hours coming from a dose over the guidance level or from a product buffered with oxide under the glycinate name and fixed by the dose and the ingredients list, with pure bisglycinate at a labelled dose with a meal producing neither in most people and an upset that persists a week after stopping having another cause. Pure bisglycinate in two small capsules: Futuro Labs Magnesium Glycinate, 300mg elemental at 80% NRV, no oxide in the list, £19.99 for 90 days at 22p a day, with a meal.

What to check on the label

Questions people also ask

Why does magnesium glycinate make me feel nauseous?

Usually a fasted capsule: any mineral salt in an empty stomach is more likely to nauseate than the same salt with food, and a large single capsule adds a heavy feeling of its own, both fixed by taking it with a meal, splitting the dose across two meals or opening the capsule into yoghurt.

Does magnesium glycinate cause diarrhoea?

Rarely at a labelled dose: the laxative effect is the unabsorbed remainder drawing water in the colon at six to twelve hours, and bisglycinate leaves a small remainder, so loose stools from a glycinate product usually mean a dose over the guidance level or a product buffered with oxide under the glycinate name.

How do I know if my stomach upset is from the magnesium?

Stop the capsule for a week: an upset that clears was the capsule, sorted by hour into the stomach's fasted-capsule nausea or the bowel's remainder effect and fixed accordingly, and an upset that persists has another cause, a new powder, a diet change or an antibiotic, or needs a GP.

Which magnesium is gentlest on the stomach?

Pure bisglycinate in a small capsule taken with a meal, absorbed well with a small remainder and no acid dependence, split across two meals for a sensitive stomach and opened into food for a reader who cannot take capsules at all.

When should stomach upset on magnesium be seen by a doctor?

When nausea or loose stools persist a week after stopping the capsule, or when vomiting, black stools, blood, severe pain or weight loss appear, none of which a magnesium capsule causes and all of which need a GP.

Sources

1. The magnesium bisglycinate absorption literature: the chelate is proposed to be absorbed partly intact through dipeptide transport and to release its magnesium with less free ion left in the gut, consistent with the lower laxative effect and good bioavailability reported for bisglycinate against citrate and oxide. PubMed record
2. The magnesium absorption kinetics literature: oral magnesium is absorbed mainly in the distal small intestine over the hours after a dose, the unabsorbed remainder reaching the colon within six to twelve hours where its osmotic effect appears, and surplus absorbed magnesium is excreted by the kidneys within a day or two. PubMed record
3. The magnesium absorption literature: fractional absorption of magnesium falls as the dose rises, so the same daily amount taken in divided doses is absorbed at a higher fraction and with less osmotic laxative effect than a single large dose. PubMed record
4. Firoz M, Graber M. Bioavailability of US commercial magnesium preparations. Magnesium Research 2001;14(4):257-262. PubMed record

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