Magnesium 375mg 180 Tablets (3 month supply)
£12.85 for 180 tablets at Boots. That works out at 4p per 100 mg magnesium, which ranks it 1st of the 9 magnesium oxide products we price across 4 UK retailers.
At one 100 mg dose a day, this pack lasts 11 months. A month is 30 days, so twelve of them is not quite a year.
How we worked it out
- Servings: 180 ÷ 2 per serving = 90
- In the pack: 90 × 375 mg = 33.8 g
- £12.85 ÷ 33.8 g × 100 mg = 3.81p per 100 mg magnesium
- A week 3.81p × 7 = 27p · a month × 30 = £1.14 · a year × 365 = £13.90
- 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.
How it compares: magnesium oxide
All 9, ranked →
Ranked purely by price per 100 mg magnesium. 91 combination products also contain magnesium.
On the label
- Magnesium · Oxide
- 375 mg per serving (stated on the label)
- Pack
- 180 tablets · 90 servings · 2 tablet(s) a serving
- Cost per serving
- 14p (90 servings in the pack)
More label details
- Sold by
- Boots
- What the listing says
- “180 Tablets” · “Take 2 tablets a day” · “Magnesium 375mg 100”
Ingredients
Magnesium Oxide, Cellulose, Colour (Calcium Carbonate), Magnesium Stearate, Cross-linked Sodium Carboxymethylcellulose, Hydroxypropylmethylcellulose, Polyvinyl Alcohol, Talc. Ingredient Per 2 Tablets %NRV Magnesium 375mg 100 1 Tablet contains 187.5mg Magnesium NRV - Nutrient Reference Value
From the Boots 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 tablets.
What you paid
Optional. At Boots today: £12.85.
“Order by” allows 3 working days’ delivery from Boots and your spare days.
Price history
No price change since 23 September 2026. Checked on 2 days, most recently 15 October 2026.
- Price at every check
- £12.85Boots
- First recorded
- £12.8523 Sept
- Checked on
- 2 dayssince 23 Sept
- First checked at Boots: £12.85
Questions about this product
How much does Boots Magnesium 375mg 180 Tablets (3 month supply) cost per 100 mg magnesium?
4p per 100 mg magnesium, from £12.85 for 180 tablets at Boots, checked on 15 October 2026.
Is it the cheapest magnesium oxide in the UK?
Yes. Of the 9 we price across 4 UK retailers, this is the cheapest per 100 mg magnesium.
How long does one pack last?
11 months at one 100 mg dose. The pack holds 33.8 g in total.
About Boots
Founded 1849 · Nottingham, England · Part of The Boots Group
Boots is a pharmacy-led health and beauty retailer founded in 1849, when John Boot opened a herbalist shop in Nottingham, where it is still based. com. It belongs to The Boots Group, owned since August 2025 by the private equity firm Sycamore Partners and Stefano Pessina's family.
All 96 Boots products, priced per doseVisit Boots (opens in a new tab)
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