Best of
Best Magnesium Supplement: Elemental mg and Price Compared
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We don't sell supplements; brands can't pay for placement; rankings use published testing and price per daily dose. How we rank
Independent of the brands we list: commission never changes a ranking. How we choose: form and dose, independent testing, ingredients and price per serving.
Affiliate disclosure: some links on this page are affiliate links. If you buy through them we may earn a commission at no extra cost to you. Commission never changes how we rank products. This is general information, not medical advice.
Magnesium is a mineral your body needs every day, and most people can get enough from food. The research shows a small drop in blood pressure in some groups and some improvement in blood sugar markers, while the evidence for sleep is weak. We rate it B. The label is tricky because products list different amounts of “elemental” magnesium, so we compare on that. Read the magnesium guide first.
Short answer: Best overall (US$): Thorne Magnesium Bisglycinate powder; Best budget (US$): Nutricost Magnesium Glycinate 210 mg; Best budget (UK £): Bulk Magnesium Glycinate 3 in 1; Low dose: Holland & Barrett and Wild Nutrition. Prices, testing and every shop are in the picks below.
Quick picks
| Pick | Product | Best for | Price | Buy |
|---|---|---|---|---|
| Best overall (US$) | Magnesium Bisglycinate powder, 60 servings | Readers paying in dollars who want a named testing certificate | $1.58 per 365 mg ($52.00 ÷ 60 servings × 365 ÷ 200 mg; checked Nov 1, 2026 at Thorne) | Thorne (affiliate link) |
| Best budget (US$) | Magnesium Glycinate 210 mg, 90 capsules | Readers paying in dollars who want the lowest price per 365 mg | $0.694 per 365 mg ($11.97 ÷ 30 servings × 365 ÷ 210 mg; checked Nov 3, 2026 at Nutricost) | Nutricost (affiliate link) |
| Best budget (UK £) | Magnesium Glycinate 3 in 1, 90 capsules | UK readers who want the lowest price per 365 mg | £0.190 per 365 mg (£8.99 ÷ 45 servings × 365 ÷ 384 mg; checked Nov 1, 2026 at Bulk) | Bulk (affiliate link) |
| Low dose per capsule | Magnesium Bisglycinate 375 mg, 90 capsules | UK readers who want a high-street bisglycinate and are happy to take several capsules | £0.920 per 365 mg (£19.29 ÷ 90 servings × 365 ÷ 85 mg; checked Nov 1, 2026 at Holland & Barrett) | Holland & Barrett (affiliate link) |
| Low dose | Food-Grown Magnesium, 60 capsules | Readers who prefer this brand and accept a high price for a low dose | £3.19 per 365 mg (£21.00 ÷ 30 servings × 365 ÷ 80 mg; checked Nov 1, 2026 at Wild Nutrition) | Wild Nutrition (affiliate link) |
Our ranked picks
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Best overall (US$)
Magnesium Bisglycinate powder, 60 servings
Magnesium bisglycinate powder, 60 servings; 1 scoop gives 200 mg magnesium, so about 1.8 scoops reach 365 mg. NSF Certified for Sport listed.
Pros
- The only magnesium product in our data with a named certificate
- Bisglycinate form
Cons
- Highest price per day of the full-dose products
- Several scoops needed to reach the 365 mg basis
United States
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Best budget (US$)
Magnesium Glycinate 210 mg, 90 capsules
Magnesium from magnesium bisglycinate, 3 capsules give 210 mg, so about 1.7 servings (5 capsules) reach 365 mg.
Pros
- Lowest price per 365 mg in dollars on this page
Cons
- The page says "Third-Party Tested" but names no certificate, so we do not count it as certified
- About 5 capsules a day to reach 365 mg
United States
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Best budget (UK £)
Magnesium Glycinate 3 in 1, 90 capsules
Magnesium bisglycinate, citrate and malate blend; 2 capsules give 384 mg elemental magnesium. The price was a sale price when we checked.
Pros
- Lowest price per 365 mg on this page in pounds
- About 365 mg is delivered by a single serving
Cons
- No testing named in our data
- One serving (384 mg) is above the NIH upper limit of 350 mg a day from supplements, so check with a doctor or pharmacist first
- Sale price valid until Nov 3, 2026
United Kingdom
- UK Buy at Bulk
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Low dose per capsule
Magnesium Bisglycinate 375 mg, 90 capsules
Magnesium bisglycinate, 1 capsule gives 85 mg elemental magnesium, so about 4.3 capsules would reach 365 mg.
Pros
- Bisglycinate form
Cons
- Needs about 4 capsules to reach 365 mg
- No testing named in our data
United Kingdom
-
Low dose
Food-Grown Magnesium, 60 capsules
Food-grown magnesium, 2 capsules give 80 mg, far below the 365 mg basis.
Pros
- Sold with prices in both £ and $
Cons
- Very high price on a 365 mg basis
- No testing named in our data
United Kingdom
How we rank
We only rank products that are in our product data file, and we use only what that file records:
- Form and amount. We compare elemental magnesium (the magnesium itself, not the whole compound) per daily serving, and we flag labels that give far less than 365 mg per serving.
- Third-party testing, as listed. We note a named testing program (for example NSF Certified for Sport) when our data lists one. Where the data says “brand statement”, we say so and do not count it as verified by us.
- Price per daily dose. We divide the pack price by the servings per pack, then scale to our basis: 365 mg of elemental magnesium a day, the typical (median) amount in the blood pressure review on our magnesium guide. It is a study amount, not a recommendation. Prices in different currencies are not converted, so $ and £ are only compared within their own currency.
Winner labels. “Best overall” goes to the cheapest product with a named testing program in that currency. “Best budget” goes to the lowest price per daily dose in that currency, whatever the testing. “Best tested” is only used when one product lists clearly more named programs than the rest. If no product qualifies for a label, we leave that label out.
Dose fit. Some products supply much less than 365 mg per serving. We still show their price on the same basis so you can see what it would cost to match the study amount, but we flag them as low dose.
What we did not do. We have not tested these products ourselves, in a lab or by taking them. We did not rank by commission. Prices change, so each price shows the date it was checked. More in How we rank.
Price per daily dose
Basis: 365 mg of elemental magnesium a day, the typical (median) amount in the blood pressure review on our magnesium guide. It is a study amount, not a recommendation. Every number below is worked out from the pack price, servings per pack and amount per serving in our product data.
US dollar prices ($)
| Product (retailer) | Amount per serving | Pack price (checked) | Price per serving | Price per daily dose | Testing named in our data |
|---|---|---|---|---|---|
| Nutricost Magnesium Glycinate 210 mg, 90 capsules (Nutricost) | 3 capsules: 210 mg magnesium (from magnesium bisglycinate) | $11.97 (Nov 3, 2026) | $11.97 ÷ 30 = $0.399 | $0.399 × 365 ÷ 210 = $0.694 | None named |
| Thorne Magnesium Bisglycinate powder, 60 servings (Thorne) | 1 scoop: 200 mg magnesium (as magnesium bisglycinate) | $52.00 (Nov 1, 2026) | $52.00 ÷ 60 = $0.867 | $0.867 × 365 ÷ 200 = $1.58 | NSF Certified for Sport |
| Wild Nutrition Food-Grown Magnesium, 60 capsules (Wild Nutrition) | 2 capsules: 80 mg magnesium | $25.00 (Nov 3, 2026) | $25.00 ÷ 30 = $0.833 | $0.833 × 365 ÷ 80 = $3.80 | None named |
UK prices (£)
| Product (retailer) | Amount per serving | Pack price (checked) | Price per serving | Price per daily dose | Testing named in our data |
|---|---|---|---|---|---|
| Bulk Magnesium Glycinate 3 in 1, 90 capsules (Bulk) | 2 capsules: 384 mg elemental magnesium (bisglycinate, citrate, malate) | £8.99 (Nov 1, 2026) | £8.99 ÷ 45 = £0.200 | £0.200 × 365 ÷ 384 = £0.190 | None named |
| Holland & Barrett Magnesium Bisglycinate 375 mg, 90 capsules (Holland & Barrett) | 1 capsule: 85 mg elemental magnesium (375 mg magnesium bisglycinate) | £19.29 (Nov 1, 2026) | £19.29 ÷ 90 = £0.214 | £0.214 × 365 ÷ 85 = £0.920 | None named |
| Wild Nutrition Food-Grown Magnesium, 60 capsules (Wild Nutrition) | 2 capsules: 80 mg magnesium | £21.00 (Nov 1, 2026) | £21.00 ÷ 30 = £0.700 | £0.700 × 365 ÷ 80 = £3.19 | None named |
Check the dose. Our basis (365 mg) sits just above the NIH upper limit of 350 mg a day from supplements and medicines. The NHS says 400 mg or less a day from supplements is unlikely to cause harm. If you plan to take more than 350 mg a day, ask a doctor or pharmacist first. Bulk’s single serving (384 mg) is above 350 mg.
Servings per pack for the capsule products are as listed in our data: Bulk 45 servings of 2 capsules, Nutricost 30 servings of 3 capsules, Wild Nutrition 30 servings of 2 capsules, Holland & Barrett 90 servings of 1 capsule.
How to start
In the studies we cite, doses ranged from about 82 mg to 637 mg of elemental magnesium a day, with a typical dose of 365 mg for 12 weeks. These are study amounts, not recommendations. Check the elemental magnesium on the label, and ask a doctor or pharmacist what amount suits you. Splitting a dose over the day is common in trials. The magnesium guide covers forms, safety and the official upper limits.
Talk to your doctor or pharmacist
Talk to your doctor or pharmacist before you start any supplement, especially if you are pregnant or breastfeeding, take prescription medicine, or have a health condition. This matters especially if you have kidney problems or take osteoporosis tablets, certain antibiotics, water tablets or acid-reducing medicine, because magnesium can interact with them. The full guide has the evidence, safety notes and citations.
How we chose
We compared five magnesium products by elemental magnesium per serving, named third-party testing and price per 365 mg. We have not tested any product ourselves, and commission does not affect the order.
FAQ
What is the best magnesium supplement?
From our data: Thorne if you want a named certificate (in dollars), Bulk for the lowest price in pounds, and Nutricost for the lowest price in dollars. Dose per serving matters as much as price, so read the label.
What is the best magnesium glycinate?
Four of the five products here use glycinate or bisglycinate. On our basis, the cheapest per 365 mg are Bulk in pounds and Nutricost in dollars, and Thorne is the one with a named certificate.
What is the best magnesium for sleep?
The evidence for sleep is weak: only three small, low-quality human trials in older adults so far. We do not rank a product for sleep. The guide explains the research.
What does elemental magnesium mean?
It is the amount of magnesium itself, not the weight of the whole compound. A capsule can be 375 mg of magnesium bisglycinate but give only 85 mg of elemental magnesium, as with the Holland & Barrett product.
This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Medical disclaimer