Third-Party Tested Magnesium Citrate: 22 Brands Checked (2026)
Of 22 magnesium citrate brands checked, 6 are on a testing list. Our pick is BulkSupplements Magnesium Citrate Powder: NSF's list names it, and 200 mg of magnesium costs $0.07. If you want softgels, Nature Made's are on the USP Verified list at $0.20 for 200 mg. Find your brand in the table.
Our pick for: a tested magnesium citrate
- Per 200 mg
- $0.07of magnesium, at Amazon prices
- A bag
- $19.97500 g of powder
- A serving
- 400 mgof magnesium in 3.5 g; half is 200 mg
- Testing list
- NSF/ANSI 173Listed by name, all bag sizes
Why we pick it NSF lists this powder by name, for every bag size. A 3.5 g serving gives 400 mg of magnesium, so half a serving gives 200 mg for $0.07. The listed softgels cost about 3 times as much for the same amount.
Which magnesium citrate brands are on a testing list?
Three more that you can buy on Amazon are on a testing list: Nature Made (USP Verified), Nature's Truth and Thorne (NSF/ANSI 173). Kirkland Signature softgels (USP, sold at Costco) and Target's up&up softgels (NSF) are listed too.
NIH sets 350 mg a day as the upper limit for magnesium from supplements. BulkSupplements, NOW and Bluebonnet each give 400 mg in a label serving, and half a 3.5 g serving or one tablet or caplet gives 200 mg.
On USP Verified: Nature Made Magnesium Citrate 250 mg
USP lists this softgel by name, and the bottle carries the USP Verified mark. Two softgels give 250 mg of magnesium for $0.26 a day ($0.20 per 200 mg, against $0.07 for the BulkSupplements powder). Choose it if you want softgels.
$0.20 per 200 mg · $15.33 for 120 softgels
Check price on AmazonAlso on NSF/ANSI 173: Nature's Truth Magnesium Citrate 250 mg
NSF lists it as Highly absorbable magnesium citrate 250 mg, 2 softgels a day. It has the same dose and form as Nature Made, at the same $0.20 per 200 mg as Nature Made, and costs 1 cent less a day than Nature Made. Pick Nature's Truth for NSF's mark, or Nature Made for USP's.
$0.20 per 200 mg · $15.09 for 120 softgels
Check price on AmazonAlso on NSF/ANSI 173: Thorne Magnesium Citrate Powder
NSF lists Thorne Magnesium Citrate (Citrus Berry Flavored), 1 scoop a day. Thorne's page gives 250 mg of magnesium a scoop, sweetened with monk fruit, to mix into water. NSF also lists Thorne's Magnesium CitraMate capsules.
$0.52 per 200 mg · $39.00 for 60 scoops
Check price on AmazonNot on a testing list: NOW, Pure Encapsulations and 14 more
These four brands are on none of the five testing lists we searched on November 12, 2026. The other 12 are in the brand table below.
Bluebonnet Magnesium Citrate 400 mg
The label gives 400 mg of magnesium in 2 caplets, so 1 caplet gives 200 mg. At $0.17 per 200 mg it suits a buyer who wants a bigger dose in each pill. BulkSupplements costs 10 cents less per 200 mg than Bluebonnet and is on NSF's list.
$0.17 per 200 mg · $20.76 for 120 caplets
Check price on AmazonNOW Magnesium Citrate 200 mg tablets
NOW's label gives 200 mg of magnesium a tablet, 400 mg in its 2-tablet serving. At $0.08 per 200 mg it costs about the same as the BulkSupplements powder ($0.07), which is on NSF/ANSI 173.
$0.08 per 200 mg · $19.99 for 250 tablets
Check price on AmazonPure Encapsulations Magnesium (Citrate)
Each capsule holds 150 mg of magnesium, and the label says to take 1 to 4 a day, so you can set your dose one capsule at a time. It is a true capsule, not a softgel.
$0.30 per 200 mg · $20.50 for 90 capsules
Check price on AmazonDouble Wood Magnesium Citrate 800 mg
Its label lists 800 mg of magnesium citrate, which holds 112 mg of magnesium, in 2 capsules a day. It suits a buyer who wants a low daily dose.
$0.31 per 200 mg · $15.46 for 180 capsules
Check price on AmazonIs your brand of magnesium citrate on a testing list?
Find your brand below: the six listed brands come first, with the name each list prints. Lists read November 12, 2026; prices are Amazon's, read November 12, 2026.
| Brand and product | Testing list |
|---|---|
| Nature MadeMagnesium Citrate 250 Mg Softgels; two citrate gummies | Yes: USP Verified |
| Nature's TruthHighly absorbable magnesium citrate 250 mg (softgels) | Yes: NSF/ANSI 173 |
| BulkSupplementsMagnesium Citrate (powder); the 1 kg bag is also on NSF Certified for Sport | Yes: NSF/ANSI 173 |
| ThorneMagnesium Citrate (Citrus Berry Flavored) powder; Magnesium CitraMate capsules | Yes: NSF/ANSI 173 |
| Kirkland SignatureMagnesium Citrate 250 mg Softgels (Costco) | Yes: USP Verified |
| up&up (Target)Highly Absorbable Magnesium Citrate 250mg (softgels) | Yes: NSF/ANSI 173 |
| BluebonnetMagnesium Citrate 400 mg caplets | Not on a testing list |
| NOWMagnesium Citrate 200 mg tablets | Not on a testing list |
| Pure EncapsulationsMagnesium (Citrate) capsules | Not on a testing list |
| Double WoodMagnesium Citrate 800 mg capsules | Not on a testing list |
| Natural VitalityCalm powder, now sold as MaxCalm (citrate and glycinate) | Not on a testing list |
| SolgarMagnesium Citrate tablets | Not on a testing list |
| Life ExtensionMagnesium (Citrate) 100 mg capsules | Not on a testing list |
| MegaFoodMagnesium Glycinate Malate Citrate capsules | Not on a testing list |
| NutricostMagnesium Citrate powder and 420 mg capsules | Not on a testing list |
| Swanson100% Pure Magnesium Citrate Powder | Not on a testing list |
| Natural FactorsMagnesium Citrate 150 mg capsules; Stress-Relax drink mix | Not on a testing list |
| Micro IngredientsPure Magnesium Citrate Powder | Not on a testing list |
| Best NaturalsMagnesium Citrate Pure Powder | Not on a testing list |
| KALMagnesium Citrate Powder | Not on a testing list |
| VitamaticMagnesium Citrate Gummies | Not on a testing list |
| Black Girl VitaminsMagnesium Citrate Gummies | Not on a testing list |
If your brand is not on a list, BulkSupplements is the tested choice at $0.07 per 200 mg: check the price on Amazon.
What do the testing lists check?
NSF International's NSF/ANSI 173 list checks that a product contains the ingredients and amounts on its label, with no unacceptable levels of contaminants. USP Verified says it tests ingredients, potency and manufacturing process. NSF Certified for Sport, Informed Sport and Informed Choice add a screen for substances banned in sport.
How do you check your own bottle?
- Search magnesium citrate on NSF's list and on USP's list.
- Match the name, the form and the serving to your bottle: Nature Made is 250 mg in 2 softgels; BulkSupplements is a 3.5 g serving of powder.
- For a brand that says "third-party tested" with no list, ask it for the certificate of analysis for your lot number.
Questions people ask
Is any magnesium citrate on a sport testing list?
From these 22 brands, one bag is. NSF Certified for Sport lists BulkSupplements Magnesium Citrate in the 1 kg bag (listing 1791472). The 500 g bag priced here is on NSF/ANSI 173. Informed Sport and Informed Choice list no magnesium citrate from these brands when searched on November 12, 2026.
Is Nature Made's 400 mg magnesium citrate on the USP list too?
No. USP lists three Nature Made citrates: the 250 mg softgels and two citrate gummies. Nature Made Extra Strength Magnesium Citrate 400 mg is not on the list.
Is the drugstore liquid magnesium citrate tested?
The 10 oz bottles from CVS, Equate and Kroger are over-the-counter laxatives sold under an FDA Drug Facts label, so supplement testing lists do not cover them. Each fluid ounce holds 1.745 g of magnesium citrate (DailyMed).
How we picked
We started from the magnesium citrate brands buyers ask about and the citrates in our catalog, 22 brands in all. On November 12, 2026 we searched NSF/ANSI 173, NSF Certified for Sport, USP Verified, Informed Sport and Informed Choice for each brand. Cost per 200 mg of magnesium lets a 112 mg and a 400 mg serving compare fairly. For capsules and softgels ranked by cost, see the best magnesium citrate capsules.
Sources
- USP Verified product list (Nature Made and Kirkland Signature magnesium citrate), quality-supplements.org, read November 12, 2026.
- NSF/ANSI 173 listings for BulkSupplements.com, Nature's Truth, Thorne and Target Corporation, info.nsf.org, read November 12, 2026.
- NSF Certified for Sport, listing 1791472; Informed Sport, sport.wetestyoutrust.com; Informed Choice, choice.wetestyoutrust.com; all read November 12, 2026.
- NIH Dietary Supplement Label Database: Nature Made 279878, Nature's Truth 339637, BulkSupplements 310739, Bluebonnet 332573, NOW 244900, Pure Encapsulations 294013, Double Wood 315677; Thorne's Magnesium Citrate page.
- NIH Office of Dietary Supplements, magnesium fact sheet (upper limit of 350 mg a day from supplements), ods.od.nih.gov.
- DailyMed Drug Facts labels for CVS Health, Equate and Kroger magnesium citrate oral solution, dailymed.nlm.nih.gov.