Ghost Fitness/Magnesium/What are the side effects of taking ZMA?
What are the side effects of taking ZMA?
The short answer
By component: zinc at 30mg causes nausea fasted and, sustained over the 25mg level, depletes copper; magnesium at 450mg as aspartate loosens stools at or over the 400mg level; B6 at 10.5mg sits at the 10mg long-term guidance level; and the fasted bedtime ritual causes the commonest side effect, nausea.
- Zinc, 30mgnausea and stomach upset fasted; copper depletion with sustained intake over the 25mg level; a metallic taste
- Magnesium, 450mg as aspartateloose stools at or over the 400mg level, aspartate being a middling salt
- Vitamin B6, 10.5mgat the UK 10mg long-term guidance level; nerve effects only far above it
- The ritualfasted at bedtime: the instruction that turns zinc's nausea from possible to likely
Our brand: the worked example on this page
Futuro Labs Magnesium Glycinate
- 22p a day
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The magnesium half without the side effects: Futuro Labs Magnesium Glycinate on Amazon UK, bisglycinate, 300mg elemental at 80% NRV with the evening meal, £19.99 for 90 days at 22p. Full label breakdown. The ZMA dose audit is on the ZMA dosage page; the zinc-and-magnesium side effects on the side-effects page.
The side effects by component, because ZMA is three doses in one capsule and each brings its own
The side effects of taking ZMA are three sets of side effects, because the formula is three doses in one capsule, and auditing them by component against the UK guidance levels is the honest way to read a tub. Zinc, 30mg per full dose: zinc salts irritate the stomach lining, so nausea, stomach upset and occasionally vomiting are the commonest zinc side effects and are far likelier fasted, the zinc-at-night pages' first gate; sustained intake above the UK guidance level of 25mg a day depletes copper by inducing the intestinal protein that binds both minerals, an effect that appears over months at doses ZMA's 30mg exceeds on its own before any multivitamin is counted, with anaemia and neurological effects at the extreme of long-term high zinc; and a metallic taste and reduced appetite are reported at higher zinc doses. Magnesium, 450mg as magnesium aspartate: at or over the 400mg supplemental guidance level, in a salt that is absorbed moderately rather than well, so the osmotic laxative effect, loose stools and, at surplus, diarrhoea, is the expected magnesium side effect of a full ZMA dose for a good share of users, the too-much ladder's first rung reached by the formula alone and doubled by anyone taking ZMA beside another magnesium. Vitamin B6, 10.5mg as pyridoxine: at the UK expert group's guidance level of 10mg for long-term supplemental B6, a level set because sustained high-dose B6, far above this, causes sensory nerve damage, so ZMA's B6 sits at the edge of its own line rather than over it, unnecessary on most diets and the origin of the vivid-dream anecdote, whose trial used many times this dose.
The ritual that causes the commonest side effect, the evidence that makes the side effects a poor trade, and the audit filed
The commonest ZMA side effect, nausea, is caused less by the zinc than by the instruction that comes with it: the classic ZMA protocol directs the dose on an empty stomach thirty to sixty minutes before bed, away from food and calcium, a ritual with no absorption evidence behind it and a zinc problem in front of it, since 30mg of zinc in an empty stomach at bedtime is the surest route to the nausea, the small-hours stomach upset and the bathroom trip that the forums report, all of which the with-food pages' standing correction, the evening meal, prevents. The evidence that makes the side effects a poor trade: the original ZMA trial, linked to the formula's developer, reported gains, and the independent replication in trained men found no effect on strength, body composition or hormones, so the formula's users accept a zinc dose over its guidance level, a magnesium dose at or over its own in a middling salt, a B6 dose at the edge of its line and a fasted ritual, for a benefit the independent trial did not find, the ZMA-worth page's verdict. The audit filed: ZMA's side effects are zinc's nausea and copper depletion at 30mg, magnesium's loose stools at 450mg as aspartate, B6 at its own 10mg level, and the fasted ritual that turns zinc's nausea from possible to likely, all avoided by two stated tubs with dinner, magnesium bisglycinate at 300mg elemental under its level and a separate 10 to 15mg zinc under its own if a diet audit says so, the worked example being the magnesium half, £19.99 for 90 days at 22p, taken with the evening meal and producing none of the above.
| The component | The side effect | The guidance level |
|---|---|---|
| Zinc, 30mg | Nausea fasted; copper depletion sustained; metallic taste | 25mg supplemental: over |
| Magnesium, 450mg aspartate | Loose stools; diarrhoea at surplus | About 400mg supplemental: at or over |
| Vitamin B6, 10.5mg | None at this dose; nerve damage far above it | 10mg long-term: at the edge |
| The fasted bedtime ritual | Nausea, stomach upset, a bathroom trip | No absorption evidence; the evening meal instead |
| The trade | Three doses at or over their lines | The independent trial found no benefit |
| The alternative | Bisglycinate at 300mg; zinc at 10 to 15mg by audit; with dinner | Under every level, no side effects |
The verdict, three doses, three side effects, and a ritual
What are the side effects of taking ZMA: by component, zinc's nausea when fasted and copper depletion when its 30mg is sustained over the 25mg guidance level, magnesium's loose stools from 450mg of aspartate at or over the 400mg level, vitamin B6 at 10.5mg sitting at the 10mg long-term guidance level with no effect at that dose, and the fasted bedtime ritual that turns zinc's nausea into the commonest complaint, all traded for a benefit the independent trial did not find. The magnesium half without the side effects: Futuro Labs Magnesium Glycinate, bisglycinate, 300mg elemental at 80% NRV with the evening meal, £19.99 for 90 days at 22p a day, a separate small zinc beside it if the audit says so.
What to check on the label
- Audit by component: zinc, magnesium, B6, each against its level.
- Expect nausea from fasted zinc: the ritual, not the mineral alone.
- Expect loose stools from 450mg aspartate: at or over the magnesium level.
- Note B6 at its 10mg line: at the edge, not over.
- Replace the formula: two tubs under both levels, with dinner.
Our brand
The worked example: Futuro Labs Magnesium Glycinate
Futuro Labs Magnesium Glycinate is the worked example for magnesium reviews because its label states every number a review needs: 1500mg magnesium bisglycinate at 20%, 300mg elemental, 80% NRV, 2 capsules a day, 180 capsules for £19.99, 22p a day, UK made, vegan HPMC shell, batch tested for lead, mercury, arsenic and cadmium, and only the register's own magnesium claims printed.
- Elemental magnesium per serving
- 300mg (80% NRV)
- Form
- magnesium bisglycinate 20%
- Serving
- 2 capsules a day
- Bottle
- 180 capsules, 90 days
- Price
- £19.99 (22p a day)
- Capsule
- vegetarian shell, vegan product
Questions people also ask
Why does ZMA make me feel sick?
Thirty milligrams of zinc in an empty stomach at bedtime, the classic ZMA instruction: zinc salts irritate the stomach lining and cause nausea fasted, and the ritual has no absorption evidence behind it, so the fix is the evening meal or two separate tubs.
Can ZMA cause diarrhoea?
Yes: its 450mg of magnesium as aspartate sits at or over the UK supplemental guidance level of about 400mg in a middling salt, so the osmotic laxative effect is the expected magnesium side effect for a good share of users.
Is the zinc in ZMA too much?
By UK guidance, yes: 30mg exceeds the 25mg supplemental level on its own, before any multivitamin, and sustained intake over that level depletes copper, so an adequacy dose of 10 to 15mg from a separate tub is the safer pattern.
Is the vitamin B6 in ZMA safe?
At 10.5mg it sits at the UK expert group's 10mg guidance level for long-term supplemental B6, a level set because sustained doses far above it damage sensory nerves; at ZMA's dose there is no effect, and most training diets make it unnecessary.
Does ZMA cause vivid dreams as a side effect?
The anecdote's likeliest origin is the B6, whose dream-vividness trial used 250mg against ZMA's 10.5mg, so the dreams are a folklore primed by expectation rather than a side effect of the dose.
Sources
- 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
- The zinc and magnesium interaction literature: very high supplemental zinc, in the region of 140mg a day, reduced magnesium absorption and balance in a metabolic study, while ordinary supplemental doses of 10 to 25mg show no meaningful interaction, and high zinc also depletes copper. PubMed record
- Wilborn CD, et al. Effects of zinc magnesium aspartate (ZMA) supplementation on training adaptations and markers of anabolism and catabolism. Journal of the International Society of Sports Nutrition 2004;1(2):12-20. PubMed record
- The vitamin B6 and dreaming literature: a small trial reported increased dream vividness and recall with 250mg of pyridoxine before bed, a dose many times the B6 in a ZMA serving, the origin of the vivid-dream anecdote. PubMed record