Cheapest Tested Magnesium Citrate Powder (2026): 11 Checked
The cheapest magnesium citrate powder on a testing list is BulkSupplements Magnesium Citrate Powder, our pick at $0.070 per 200 mg of magnesium. NSF International lists it by name on its NSF/ANSI 173 list. Of the 11 citrate powders we checked, 2 are on a testing list. The other is Thorne, at $0.520 per 200 mg.
Our pick for: the cheapest tested citrate powder
- Per 200 mg
- $0.070of magnesium, at Amazon prices
- A bag
- $19.97500 g of powder
- A serving
- 400 mgof magnesium in 3.5 g
- Testing list
- NSF/ANSI 173Listed by name, all pack sizes
Why we pick it NSF International lists BulkSupplements Magnesium Citrate (powder, 1/2 tsp, about 3.5 g) on its NSF/ANSI 173 list. It costs less per 200 mg than the other powders we priced. Thorne, the one other powder on a testing list, costs $0.520.
What is the cheapest magnesium citrate powder that is third-party tested?
BulkSupplements Magnesium Citrate Powder, at $0.070 per 200 mg of magnesium. Thorne is the only other citrate powder on a testing list, at $0.520. A full 3.5 g serving of the BulkSupplements powder gives 400 mg of magnesium. NIH puts the upper limit for magnesium from supplements at 350 mg a day. Use half a serving, 1.75 g on a gram scale: that is 200 mg for $0.070.
Also on NSF/ANSI 173: Thorne Magnesium Citrate Powder
NSF lists Thorne Magnesium Citrate (Citrus Berry Flavored) as a powder, 1 scoop (3.25 g), all pack sizes, read November 11, 2026. Each scoop gives 250 mg of magnesium, and the 60-serving tub is citrus berry flavored. It costs about 7 times as much per 200 mg as our pick. Buy it if you want a flavored mix.
$0.520 per 200 mg · $39.00 for 60 servings
Check price on AmazonNot on a testing list: NOW, Nutricost, Natural Factors and six more
These are the other citrate powders in our checks. NOW costs about the same per 200 mg ($0.072 against $0.070) and is not on a testing list. Only the BulkSupplements powder is on a testing list.
NOW Magnesium Citrate Pure Powder
NOW's label gives 450 mg of magnesium in a 3 g level teaspoon, 76 servings in the 8 oz bag. It is a plain unflavored powder that mixes into cold water.
$0.072 per 200 mg · $12.24 for 76 servings
Check price on AmazonNutricost Magnesium Citrate Powder
Nutricost's label gives 210 mg of magnesium a scoop, in unflavored 250 g and 500 g bags. The 500 g label says "Third Party Tested", which is the maker's claim, and no testing list names it.
$12.95 for the 250 g bag
Check price on AmazonNatural Factors Stress-Relax Magnesium Citrate Drink Mix
Natural Factors makes a berry drink mix with stevia: 300 mg of magnesium in a 3.3 g scoop, 75 scoops in the 250 g tub, stirred into warm water.
$0.186 per 200 mg · $20.97 for 75 servings
Check price on AmazonSix more powders are in the table below: Natural Vitality Calm in two sizes, Swanson, Best Naturals, KAL and Micro Ingredients. No testing list names any of them.
What do the testing lists check?
NSF International's NSF/ANSI 173 list checks that what is in the product matches the label, with no undeclared ingredients or unacceptable levels of contaminants. NSF Certified for Sport, Informed Sport and Informed Choice test for banned substances. USP Verified checks ingredient identity and amount, purity and manufacturing quality.
How do you check your own bag?
- Open NSF's list and search the product name, such as magnesium citrate.
- Match the brand, the form and the serving to your bag.
- For a brand that says "third-party tested" with no list, ask the brand for the lab report for your lot number.
How do the citrate powders compare per 200 mg?
Lowest cost per 200 mg of magnesium first, at Amazon prices read November 12, 2026 and each label's serving. Cost is the price divided by servings times the magnesium in a serving, over 200. Amazon prices change, so the order can too.
| Product and testing list | Per 200 mg | Label serving and price |
|---|---|---|
| BulkSupplements Magnesium Citrate PowderNSF/ANSI 173 | $0.070 | 400 mg of magnesium per 3.5 g, once a day, $19.97 |
| NOW Magnesium Citrate Pure PowderNot on a testing list | $0.072 | 450 mg of magnesium per 3 g (1 level teaspoon), $12.24 |
| Natural Factors Stress-Relax Drink MixNot on a testing list | $0.186 | 300 mg of magnesium per 3.3 g scoop, $20.97 |
| Natural Vitality Calm Watermelon, 8 ozNot on a testing list | $0.257 | 290 mg of magnesium per 4 g, from magnesium carbonate, $20.85 |
| Thorne Magnesium Citrate PowderNSF/ANSI 173 | $0.520 | 250 mg of magnesium per scoop, $39.00 |
| Natural Vitality Calm, 16 ozNot on a testing list | – | 2 teaspoons (4 g) in water, $22.11 |
| Nutricost Magnesium Citrate PowderNot on a testing list | – | 210 mg of magnesium per scoop, $12.95 |
Questions people ask
Does the NSF listing cover the 500 g BulkSupplements bag?
NSF lists BulkSupplements Magnesium Citrate as a powder with a serving of 1/2 tsp (about 3.5 g) and the pack shown as "All". The bag we link holds 500 g and gives 400 mg of magnesium in 3.5 g.
Is "third-party tested" on a label the same as being on a list?
No. A line on the label is the maker's claim. A testing list names the exact product, so you can look it up yourself.
Why does this page compare cost per 200 mg, not per scoop?
Scoops hold very different amounts of magnesium. Among the powders here, a label serving runs from 160 mg (KAL) to 630 mg (Swanson), so cost per 200 mg puts them on one scale.
Does NSF Certified for Sport list the BulkSupplements powder?
NSF Certified for Sport lists a BulkSupplements magnesium citrate in a 1 kg bag. The bag we link is 500 g, so the listing this page uses is NSF/ANSI 173.
How we picked
We started from the 11 magnesium citrate powders in our checks, then searched NSF/ANSI 173, NSF Certified for Sport and USP Verified on November 11, 2026 and Informed Sport and Informed Choice on November 12, 2026 for each. We read each label's magnesium and serving from NIH's label database and priced each bag on Amazon on November 12, 2026. For capsules and softgels, see magnesium citrate supplements; for mixes in other forms, see the best magnesium drink mix and the cheapest magnesium glycinate.
Sources
- NSF/ANSI 173 list: BulkSupplements.com (Hard Eight Nutrition LLC) MAGNESIUM CITRATE, powder, and Thorne Magnesium Citrate (Citrus Berry Flavored), info.nsf.org, read November 11, 2026.
- NSF Certified for Sport, certified product search, read November 11, 2026. USP Verified, quality-supplements.org, read November 11, 2026. Informed Sport and Informed Choice, wetestyoutrust.com, read November 12, 2026.
- NIH Office of Dietary Supplements, Magnesium fact sheet for health professionals, upper limit for supplements.
- NIH Dietary Supplement Label Database, dsld.od.nih.gov, labels for each powder.