DeliveredDose

Magnesium Oxide

Capsules and powders are ranked separately: each has its own pick and its own table, and neither is priced against the other.

Capsules, softgels and tablets

Cheapest per 200mg, delivery known
Nature Made Magnesium 250 mg (200 tablets)
$0.08per 200mg, delivered$2.39 a month
How these lines are chosen

Among 8 products and 8 retailer listings we track; Amazon and Walmart are not included. A month is thirty doses of the size in the heading, priced the same way as the per-dose figure beside it. “Delivery known” ranks only products whose retailer publishes a delivery rate; a cheaper product with an unpublished rate is on its own line, or in the full list below.

Nothing here clears every bar, so there is no pick

A pick has to be independently certified, at the exact package sold where the certifier names packages, and carry no recall or failed test. Where a retailer does not publish a delivery rate, the pick is priced before delivery and says so. Nothing here clears that bar yet. These came closest, with what stopped each one:

Nature Made Magnesium 250 mg (200 tablets) $0.048 per 200mg, no independent verification we could locate. Free delivery starts at $25.00, so this order is $13.11 short.
Nature Made Magnesium 250 mg (100 tablets) $0.05 per 200mg, no independent verification we could locate. Free delivery starts at $25.00, so this order is $18.81 short.
Sports Research Magnesium Oxide, Biolipid Delivery (90 softgels) $0.10 per 200mg, no independent verification we could locate. Free delivery starts at $50.00, so this order is $31.05 short.

“Delivery cost is not published” usually means the retailer only publishes a free-delivery threshold and no rate below it. Adding anything else to the same order clears it. We cannot price that cart for you, so we show the gap instead of guessing.

Powder

Nothing here clears every bar, so there is no pick

A pick has to be independently certified, at the exact package sold where the certifier names packages, and carry no recall or failed test. Where a retailer does not publish a delivery rate, the pick is priced before delivery and says so. Nothing here clears that bar yet. These came closest, with what stopped each one:

BulkSupplements.com Magnesium Oxide Powder (250 g) $0.027 per 200mg, no independent verification we could locate; delivery cost is not published. Free delivery starts at $59.00, so this order is $39.03 short.
BulkSupplements.com Magnesium Oxide Powder (100 g) $0.067 per 200mg, no independent verification we could locate; delivery cost is not published. Free delivery starts at $59.00, so this order is $39.03 short.
BulkSupplements.com Magnesium Oxide Powder (1 kg) $0.01 per 200mg, no independent verification we could locate; delivery cost is not published; more than a year's supply at one labeled serving a day (1,198 servings). Free delivery starts at $59.00, so this order is $28.03 short.

“Delivery cost is not published” usually means the retailer only publishes a free-delivery threshold and no rate below it. Adding anything else to the same order clears it. We cannot price that cart for you, so we show the gap instead of guessing.

The salt that carries the most magnesium per gram of compound, and commonly described as the least well absorbed, which is a claim this site reports rather than measures. Price per dose flatters it, and that is the point of showing it.

Prices checked daily. Every figure links to its source. Where the data comes from

Of the 12 products here: none in any database we searched.

Capsules, softgels and tablets
8 of 8 products
5 rows marked + delivery exclude an unpublished delivery charge, so their real cost per dose is higher.
Tested? A Certified · B Tested · C Claimed · D None located · A? listed, but not at this size
ProductDelivery
Nutricost Magnesium Oxide 400 mg (240 capsules)
capsule · 400mg per serving · 0.50 per dose
$0.033
$1.00/mo
+ delivery
D · None located
Could not locate independent data
$15.97
checked today
not free
$43.03 short
240
= 480 doses
16 months at 1/day
Buy
Nutricost (direct)
Nutricost Magnesium Oxide 750 mg (240 capsules)
capsule · 420mg per serving · 0.48 per dose
$0.034
$1.01/mo
+ delivery
D · None located
Could not locate independent data
$16.97
checked today
not free
$42.03 short
240
= 504 doses
17 months at 1/day
Buy
Nutricost (direct)
Micro Ingredients Magnesium Oxide (500 capsules)
capsule · 240mg per serving · 0.83 per dose
$0.04
$1.20/mo
+ delivery
D · None located
Could not locate independent data
$23.95
checked today
not free
$35.05 short
500
= 600 doses
20 months at 1/day
Buy
Micro Ingredients (direct)
Nature Made Magnesium 250 mg (200 tablets)
tablet · 250mg per serving · 0.80 per dose
$0.048
$1.43/mo
C · Claimed
Claimed, not confirmed
$11.89
checked today
$8.00200
= 250 doses
8.2 months at 1/day
Buy
Nature Made (direct)
Nature Made Magnesium 250 mg (100 tablets)
tablet · 250mg per serving · 0.80 per dose
$0.05
$1.49/mo
C · Claimed
Claimed, not confirmed
$6.19
checked today
$8.00100
= 125 doses
4.1 months at 1/day
Buy
Nature Made (direct)
BulkSupplements.com Magnesium Oxide Capsules (180 count)
capsule · 500mg per serving · 0.40 per dose
$0.051
$1.53/mo
+ delivery
D · None located
Could not locate independent data
$22.96
checked today
not free
$36.04 short
180
= 450 doses
15 months at 1/day
Buy
BulkSupplements.com
Nutricost Magnesium Oxide 375 mg (240 capsules)
capsule · 210mg per serving · 0.95 per dose
$0.051
$1.54/mo
+ delivery
D · None located
Could not locate independent data
$12.97
checked today
not free
$46.03 short
240
= 252 doses
8.3 months at 1/day
Buy
Nutricost (direct)
Sports Research Magnesium Oxide, Biolipid Delivery (90 softgels)
softgel · 420mg per serving · 0.48 per dose
$0.10
$3.01/mo
D · None located
Could not locate independent data
$18.95
checked 3 days ago
$7.5090
= 189 doses
6.2 months at 1/day
Buy
Sports Research (direct)
Powder
4 of 4 products
4 rows marked + delivery exclude an unpublished delivery charge, so their real cost per dose is higher.
Tested? A Certified · B Tested · C Claimed · D None located · A? listed, but not at this size
ProductDelivery
BulkSupplements.com Magnesium Oxide Powder (1 kg)
powder · 1000 g · 500mg per serving · 0.40 per dose
$0.01
$0.31/mo
+ delivery
D · None located
Could not locate independent data
$30.97
checked today
not free
$28.03 short
1,198
= 2995 doses
8.2 years at 1/day
Buy
BulkSupplements.com
BulkSupplements.com Magnesium Oxide Powder (500 g)
powder · 500 g · 500mg per serving · 0.40 per dose
$0.017
$0.52/mo
+ delivery
D · None located
Could not locate independent data
$25.97
checked today
not free
$33.03 short
599
= 1498 doses
4.1 years at 1/day
Buy
BulkSupplements.com
BulkSupplements.com Magnesium Oxide Powder (250 g)
powder · 250 g · 500mg per serving · 0.40 per dose
$0.027
$0.80/mo
+ delivery
D · None located
Could not locate independent data
$19.97
checked today
not free
$39.03 short
299
= 748 doses
2.0 years at 1/day
Buy
BulkSupplements.com
BulkSupplements.com Magnesium Oxide Powder (100 g)
powder · 100 g · 500mg per serving · 0.40 per dose
$0.067
$2.00/mo
+ delivery
D · None located
Could not locate independent data
$19.97
checked today
not free
$39.03 short
120
= 300 doses
9.9 months at 1/day
Buy
BulkSupplements.com

Common questions

How much does magnesium cost per dose?
What 200 mg of elemental magnesium costs across every magnesium we price, cheapest to most expensive, with the salt each panel names. Before delivery.
What is the cheapest magnesium per dose?
Every magnesium we track, priced per 200 mg of elemental magnesium, not per capsule or bottle, grouped by salt. The salt and the brand both move the price.
Magnesium glycinate vs citrate: what is the difference?
What each form costs per 200 mg of elemental magnesium, how many capsules that takes, and what the Supplement Facts panels say. Absorption is not compared.
Is magnesium glycinate actually all glycinate?
Some products sold as one magnesium salt name a second salt on their own Supplement Facts panel. What each panel we have read says, by product.
Which magnesium brands are third-party tested?
Every magnesium we track, grouped by whether a certifier names the exact package sold, only another size, or nothing we found. By salt.
Magnesium glycinate vs malate: what is the difference?
What each form costs per 200 mg of elemental magnesium, how many capsules that takes, and what the Supplement Facts panels name. Absorption is not compared.
Why is magnesium L-threonate so much more expensive?
L-threonate costs many times more per 200 mg of elemental magnesium than glycinate. Little of the compound is magnesium, and that is most of the gap.
Magnesium citrate vs oxide: what is the difference?
What oxide and citrate each cost per 200 mg of elemental magnesium, how many units a dose takes, and what each panel names.
Do third-party tested supplements cost more?
The cheapest product we track in each category beside the cheapest one a certifier names at the exact package, where one exists, and the gap per dose.
Magnesium glycinate vs taurate: what is the difference?
Magnesium glycinate and taurate priced per 200 mg of elemental magnesium, with the capsules each takes and what the labels name. Absorption is not compared.
How many capsules of magnesium do you have to take?
How many capsules, softgels or scoops each magnesium product needs to reach 200 mg of elemental magnesium. The number varies widely across products.
Is BulkSupplements third party tested?
Every BulkSupplements product we track, by whether a certifier names the exact package sold, only another size, or nothing we found. With listing IDs.
Do supplement travel packs cost more per dose?
Every travel pack or single-serve packet we price, next to the same brand’s smallest tub or bottle of the same product, per comparison dose.
Is Thorne magnesium NSF certified?
Thorne magnesium bisglycinate, glycinate capsules and citrate checked against NSF Certified for Sport: which package each listing names, with the listing IDs.
What is the cheapest NSF certified magnesium?
Every magnesium we track whose exact package NSF names in its Certified for Sport database, ranked by cost per 200 mg of elemental magnesium, by salt.
Is Thorne third party tested?
Every Thorne product we price, checked in NSF’s Certified for Sport database: which listing names the exact package sold, with the listing IDs.
Is Core Med Science third party tested?
Every Core Med Science product we price, checked in NSF’s Certified for Sport database: which listing names the exact package sold, and the IDs.
Is Optimum Nutrition third party tested?
Every Optimum Nutrition product we track, checked in the certifier databases: what each listing covers, package by package, with the listing IDs.
Is Momentous third party tested?
Every Momentous product we price, checked in NSF’s Certified for Sport database: where a listing names the exact package, and where it names another size.
Is BulkSupplements magnesium NSF certified?
Every BulkSupplements magnesium we price, checked in NSF’s Certified for Sport database: which bags a listing names, which it does not, and the listing IDs.
Is Momentous magnesium NSF certified?
Momentous magnesium bisglycinate, L-threonate and malate checked against NSF Certified for Sport: which bottle each listing names, with the listing IDs.
Is BPN third party tested?
Every Bare Performance Nutrition product we price, checked in NSF’s Certified for Sport database: which package each listing names, and which it does not.
How much elemental magnesium is in magnesium glycinate?
What the milligrams on a magnesium label mean: the compound weight a bottle names, the elemental magnesium its panel states, and how the two differ by form.
Which supplements are NSF Certified for Sport?
Every package we price that NSF names in its Certified for Sport database, by category, with the listing IDs and what each listing actually covers.
Do supplement prices actually change?
We re-read every price we can read automatically each day and keep every reading. Which prices have moved since we started, which have not, and by how much.
How many capsules is one serving?
How many pills the label calls one serving, across every capsule, tablet and softgel we price, and what that does to the count on the front of the bottle.
Is BUBS Naturals third party tested?
Every BUBS Naturals product we price, checked in NSF’s Certified for Sport database: which listing names the exact package sold, with the listing IDs.
Is Sports Research third party tested?
Every Sports Research product we track, checked in the certifier databases: which program lists each one, and which no database we searched lists.
Is Nature Made third party tested?
Every Nature Made product we price, checked against USP’s Verified Products directory and its own label: which packages carry both, product by product.
Is Nature Made magnesium USP Verified?
Nature Made magnesium glycinate, citrate and oxide checked against USP’s Verified directory and each label’s mark, package by package.

Every magnesium question in one place

About these numbers

What “per dose” means here: 200mg elemental magnesium

The NIH fact sheet gives an adult RDA of 310-420 mg of magnesium, so 200 mg is a little under half of that. It is a round number chosen as a common denominator across salts that carry very different amounts of magnesium per gram. It is a unit of comparison, not a recommended intake.

Compared on elemental magnesium. Oxide carries more magnesium per gram than any common form, which is why it produces a low cost per dose; absorption is a separate question this figure does not answer.

Source: NIH Office of Dietary Supplements, Magnesium - Health Professional Fact Sheet · checked Aug 25, 2026
Where the data comes from
Every claim links to its source. Products, prices and certification listings are read from the retailers' own stores and the certifiers' own databases, and each figure links to the record it came from, so you can check any of them.
  • Where a label does not state servings per container, the figure is derived from net weight and the product page says so.
  • Amazon and Walmart are not included, so “cheapest” means cheapest among the retailers we track.
  • Prices go stale. Each one shows when it was last checked, and says so when it is older than the retailer allows us to cache it.
  • iHerb prices cannot be refreshed automatically. iHerb has not given us access to its price data, so those prices are marked stale until they are re-read. Each retailer offer carries its own check date.
Found something wrong? Tell us. Corrections are the point.
How we make money

No Buy button on this page earns us anything. The only links on the site that can are the Amazon links shown below the price comparison on some product pages, outside the comparison, and each says so beside it.

Commission will play no part in what we list, how it ranks, or which link we send you to. The Buy button points at the lowest price we have recorded even when that retailer pays us nothing.