Magnesium Glycinate X3 90 Brand New, 90 capsules
£13.99 for 90 capsules at Protein Works. That works out at 8p per 100 mg magnesium, which ranks it 31st of the 79 magnesium blends and other forms we price across 15 UK retailers.
At one 100 mg dose a day, this pack lasts 6 months. A month is 30 days, so twelve of them is not quite a year.
How we worked it out
- Servings: 90 ÷ 2 per serving = 45
- In the pack: 45 × 384 mg = 17.3 g
- £13.99 ÷ 17.3 g × 100 mg = 8.1p per 100 mg magnesium
- A week 8.1p × 7 = 57p · a month × 30 = £2.43 · a year × 365 = £29.55
- Amount per serving: stated on the label.
The standard dose is a comparison unit, not a recommendation. Always confirm the price on the retailer's site. How we compare everything.
Cheaper magnesium blends and other forms
All 79, ranked →
Switching to the Bulk pack saves 87p a month at the same 100 mg dose.
Ranked purely by price per 100 mg magnesium. 236 combination products also contain magnesium.
On the label
- Magnesium · Blends and other forms
- 384 mg per serving (stated on the label)
- Pack
- 90 capsules · 45 servings · 2 capsule(s) a serving
- Cost per serving
- 31p (45 servings in the pack)
More label details
- Barcode
- 5061062526636
- Sold by
- Protein Works
- What the listing says
- “Per 2 Capsules” · “[Magnesium ; 1813mg]” · “confirmed from the retailer's own product page, not this listing's text: form id other; amount per serving 384.0; amount unit mg; amount refers to elemental; units per serving 2.0; pack units 90; pack unit type capsule”
Ingredients
Magnesium Bisglycinate, Magnesium Citrate, Magnesium Malate, Capsule Shell (Hydroxypropyl Methyl Cellulose), Anti-Caking Agent (Magnesium Stearate).
From the Protein Works listing. Check the pack itself if you have an allergy: labels mark allergens in bold.
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One 100 mg dose is our comparison unit, not a recommendation.
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Filled in from the label’s serving: 2 capsules.
What you paid
Optional. At Protein Works today: £13.99.
“Order by” allows 5 working days’ delivery from Protein Works and your spare days.
Price history
No price change since 23 September 2026. Checked on 2 days, most recently 9 October 2026.
- Price at every check
- £13.99Protein Works
- First recorded
- £13.9923 Sept
- Checked on
- 2 dayssince 23 Sept
- First checked at Protein Works: £13.99
Questions about this product
How much does Protein Works Magnesium Glycinate X3 90 Brand New cost per 100 mg magnesium?
8p per 100 mg magnesium, from £13.99 for 90 capsules at Protein Works, checked on 9 October 2026.
Is it the cheapest of the magnesium blends and other forms in the UK?
No, it is 31st of 79. Magnesium 500mg at ZipVit works out at 1p per 100 mg magnesium.
How long does one pack last?
6 months at one 100 mg dose. The pack holds 17.3 g in total.
About Protein Works
Founded 2012 · Liverpool, England · Part of Lactalis
Protein Works is a British nutrition company founded in 2012 by Mark Coxhead, Nick Smith and Karl Jacobie. It is based at PW Campus in Speke, Liverpool, which opened in 2025 and replaced several sites in Runcorn.
All 149 Protein Works products, priced per doseVisit Protein Works (opens in a new tab)
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