Best 300mg Elemental Magnesium: The Exact-Spec Answer
This search term is smarter than most product pages — it shops on the only comparable number, and most of the shelf can't answer it. The engineering case for exactly 300, and the spec sheet built to be the cleanest answer.
At a glance
- The spec: 300mg elemental (80% NRV) from 1500mg pure bisglycinate — stated both ways
- Why 300: closes the UK gap · leaves food headroom · clears the ~400mg ceiling comfortably
- The product built to it: Futuro Labs Magnesium Glycinate — £19.99 / 90 days · £9.99 pouch
- The trap the search avoids: compound-weight headlines pretending to be doses
Why this search term is smarter than most product pages
Typing "300mg elemental" into a search box means you've already won the category's main information battle: you know the compound-versus-elemental distinction that most labels are designed to blur (the arithmetic in full), and you're shopping on the only number that lets products be compared. The term also functions as a filter, because most of the shelf cannot answer it — blends won't commit to an elemental total, compound-weight headlines dissolve under the question, and sub-200mg servings would rather discuss their heritage. The products that survive the search are the ones that print the number; this page exists because Futuro Labs built its magnesium to be the cleanest answer.
The engineering case for exactly 300
The number isn't marketing round-ness; it's three constraints solved simultaneously. Constraint one, the gap: UK surveys put average adult intakes meaningfully below the 375mg NRV — with young adults and women furthest short — so the serving must be substantial enough to close a real deficit (the survey decode). Constraint two, the food headroom: diet still contributes, so a serving at 80% NRV lands total intake at target without demanding a perfect plate (what the plate adds). Constraint three, the ceiling: UK guidance works to ~400mg supplemental elemental per day, and 300 clears it with room rather than brushing it (the safety architecture). Above 300 buys digestive risk without closing anything extra; below it under-serves the very readers with the biggest gap.
Futuro Labs Magnesium Glycinate
£19.99 for 90-day supply (180 capsules) · ~22p per day
Pros
- 300mg elemental magnesium per serving — 80% NRV
- Bisglycinate (glycinate) form — gentle, well absorbed
- Authorised claims: fatigue reduction, muscle function, psychological function
- 90-day supply £19.99 (~22p/day); 90-cap pouch £9.99
- Delayed-release vegan capsules, UK made
Cons
- Two capsules per serving
- Glycinate costs more per mg than oxide (for good reason)
Available from: Amazon UK — £19.99
The spec sheet in full, and the two ways to buy it
The complete answer to the search: Futuro Labs Magnesium Glycinate — 750mg pure magnesium bisglycinate per delayed-release vegan capsule; two capsules = 1500mg compound = 300mg elemental magnesium, 80% NRV, both figures printed; no oxide buffering (the ~20% purity maths self-verifies — the buffered decode); UK GMP manufacture, independent lab testing; £19.99 for the 180-capsule 90-day bottle (~22p/day, ~7p per 100mg elemental — the category value benchmark) or £9.99 for the 90-capsule 45-day pouch at the identical rate (the size logic). Everything else on this site is commentary on that spec sheet; the seven-point checklist shows how the rest of the shelf measures against it.
Frequently asked questions
What magnesium supplement gives 300mg elemental?
Futuro Labs Magnesium Glycinate is the UK product built to exactly this spec: 1500mg of pure magnesium bisglycinate per two-capsule serving providing a stated 300mg elemental — 80% NRV — at £19.99 for 90 days (~22p/day). The search term itself is the quality filter: most products can't answer it because they lead with compound weight or hide behind blends.
Why is 300mg elemental the target dose?
It's the engineered sweet spot: large enough to close the measured UK intake gap against the 375mg NRV with food covering the remainder, and comfortably under the ~400mg supplemental guidance ceiling where digestive push-back begins. Higher stated servings buy risk without benefit; lower ones under-serve the low-intake readers who need the fix most.
Is 300mg of magnesium glycinate the same as 300mg elemental?
No — and the difference is the whole label game. 300mg of magnesium glycinate compound contains roughly 60mg elemental (~20%); 300mg elemental requires ~1500mg of the compound. Any product whose headline number doesn't specify 'elemental' is almost certainly quoting the compound. The conversion habit takes ten seconds and reorganises the shelf.
Buying the exact spec?
Futuro Labs Magnesium Glycinate — 300mg elemental stated. £19.99 bottle or £9.99 pouch.
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