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Magnesium Oxide: price per 100 mg magnesium

We count the elemental magnesium a product provides, not the weight of the whole compound it comes in. If a label states the magnesium amount, we use it. If it only gives the compound's weight, we estimate using a published conversion factor and mark the figure “estimated”. If we cannot tell which the number means, the product is listed as unverified and is not ranked.

Conversion factor used when only the compound weight is given: oxide 60.3%. How we chose these.

Prices last checked: 17 September 2026. Ranked purely by price per 100 mg magnesium — a comparison unit, not a recommendation. We may earn commission from these links; it never affects the order.

Product	Pack	Per serving	Per 100 mg magnesium	Per month	Lasts	Buy
1 Essential Magnesium TabletsMyvitamins · Myproteinships from — check delivery and dutiesclaimed: vegan	270 tablets · 90 servings	300 mg	£0.0500	£1.50	9 months	£13.49View at Myprotein
Show the working Servings: 270 ÷ 3 per serving = 90 In the pack: 90 × 300 mg = 27 g £13.49 ÷ 27 g × 100 mg = £0.0500 per 100 mg magnesium Amount per serving: stated on the label. From the retailer's listing: pack units “270 Tablets” units per serving “Consume 3 tablets daily” amount per serving “Magnesium ; 300mg ; 80” form raw “Magnesium Oxide” Is this wrong? Tell us
2 Essential Magnesium TabletsMyvitamins · Myproteinships from — check delivery and dutiesclaimed: vegan	90 tablets · 30 servings	300 mg	£0.0610	£1.83	3 months	£5.49View at Myprotein
Show the working Servings: 90 ÷ 3 per serving = 30 In the pack: 30 × 300 mg = 9 g £5.49 ÷ 9 g × 100 mg = £0.0610 per 100 mg magnesium Amount per serving: stated on the label. From the retailer's listing: pack units “90 Tablets” units per serving “Consume 3 tablets daily” amount per serving “Magnesium ; 300mg ; 80” Is this wrong? Tell us
+ Magnesium 375mg 90 TabletsHealthspanCombination: price counts the magnesium onlyalso contains vitamin c, vitamin b12, vitamin b1…ships from — check delivery and duties	90 tablets · 90 servings	375 mg	£0.0385	£1.15	11 months	£12.99View at Healthspan
Show the working Servings: 90 ÷ 1 per serving = 90 In the pack: 90 × 375 mg = 33.8 g £12.99 ÷ 33.8 g × 100 mg = £0.0385 per 100 mg magnesium Amount per serving: stated on the label. Also contains: vitamin c, vitamin b12, vitamin b1, vitamin b2, niacin, pantothenic acid, vitamin b6, folic acid, biotin. The price counts the magnesium only. From the retailer's listing: pack units “90 Tablets” units per serving “Swallow 1 tablet daily” servings stated “90 Tablets” amount per serving “Magnesium ; 375 mg ; 100% NRV” Is this wrong? Tell us
+ Magnesium Plus 120 TabletsHealthspan Elite · HealthspanCombination: price counts the magnesium onlyalso contains vitamin c, vitamin b12, vitamin b1…ships from — check delivery and duties	120 tablets · 120 servings	375 mg	£0.0400	£1.20	1.2 years	£17.99View at Healthspan
Show the working Servings: 120 ÷ 1 per serving = 120 In the pack: 120 × 375 mg = 45 g £17.99 ÷ 45 g × 100 mg = £0.0400 per 100 mg magnesium Amount per serving: stated on the label. Also contains: vitamin c, vitamin b12, vitamin b1, vitamin b2, niacin, pantothenic acid, vitamin b6, folic acid, biotin. The price counts the magnesium only. From the retailer's listing: pack units “120 Tablets” units per serving “Swallow 1 tablet daily with water” amount per serving “Magnesium ; 375 mg ; 100% NRV” Is this wrong? Tell us

Nothing from UK-based sellers here yet. Tick the boxes under “Show” to include combination products or sellers shipping from abroad.

How we compare · All magnesium forms