Best Potassium and Magnesium (2026): 6 Checked, 2 Tested
Buy Life Extension Potassium with Extend-Release Magnesium. One capsule gives 250 mg of magnesium and 99 mg of potassium for $0.16 a day. Want both as citrates? Nutricost gives 210 mg and 99 mg in 2 capsules for $0.12 a day. Want potassium alone on a testing list? Thorne is on NSF/ANSI 173 for $0.19 a day.
Our pick for: magnesium and potassium in one capsule
- A day
- $0.161 capsule at Amazon's price.
- A pack
- $9.5660 capsules, 60 days
- In 1 capsule
- 250 mg magnesiumAs citrate and ZumXR oxide
- Potassium
- 99 mgAs potassium chloride
Why we pick it One capsule holds both minerals, so you need no second bottle. It has 250 mg of magnesium, under the 350 mg limit, and a 60-capsule bottle lasts 60 days. The label says 1 capsule once or twice a day. Two a day is 500 mg of magnesium, over that limit.
What is the best magnesium supplement with potassium?
Most potassium pills are potassium only, so the magnesium comes from a second product or from one of two combined capsules. We checked six products sold on Amazon: four potassium-only and two with both minerals. Each has its own choice below.
Nutricost Potassium and Magnesium Citrates
2 capsules give 210 mg of magnesium as citrate and 99 mg of potassium as citrate. Choose it if you want both minerals as citrate at $0.12 a day.
$0.12 a day · $13.95 for 120 days
Check price on AmazonThorne Potassium Citrate, to take beside your magnesium
NSF/ANSI 173 lists Thorne Potassium Citrate by name. Its label gives 99 mg of potassium as citrate in 1 capsule. Choose it if you want potassium alone on a testing list. Take it with Revive MD, 200 mg of magnesium as glycinate, and the two cost $0.52 a day.
$0.19 a day · $17.00 for 90 days
Check price on AmazonRevive MD Magnesium Glycinate, the magnesium to take beside it
Potassium and magnesium are two separate products here, so each keeps its own label amount. 2 capsules of Revive MD give 200 mg of magnesium as glycinate for $0.33 a day.
$0.33 a day · $19.99 for 60 days
Check price on AmazonNature Made Potassium Gluconate 550 mg, on USP Verified
The USP Verified list names Nature Made Potassium Gluconate 550 Mg Tablets. The label gives 90 mg of potassium as gluconate in 1 tablet. Choose it if you want potassium alone at $0.04 a day, as gluconate.
$0.04 a day · $4.19 for 100 days
Check price on AmazonNOW Potassium Citrate 99 mg
The label gives 99 mg of potassium as citrate in 1 capsule. Choose it if you want a citrate capsule at $0.05 a day.
$0.05 a day · $8.70 for 180 days
Check price on AmazonHorbaach Potassium Citrate 275 mg
The label gives 99 mg of potassium in 1 capsule, from 275 mg of potassium citrate. The big number on the front is the weight of the citrate; the potassium is 99 mg. The bottle holds 400 servings. Choose it if you want the lowest cost a day in citrate.
$0.04 a day · $17.96 for 400 days
Check price on AmazonHow much potassium and magnesium does a serving give, and what does it cost?
The six products, at Amazon prices read November 12, 2026. Potassium and magnesium are the amounts on each label's panel for the serving shown. A day is the price divided by the days a pack lasts at that serving a day.
| Product and serving | Potassium | Magnesium | A day |
|---|---|---|---|
| Life Extension Potassium with Extend-Release Magnesium60 capsules; 1 capsule; potassium chloride; not on a testing list | 99 mg | 250 mg | $0.16 |
| Nutricost Potassium and Magnesium Citrates240 capsules; 2 capsules; potassium citrate; not on a testing list | 99 mg | 210 mg | $0.12 |
| Thorne Potassium Citrate90 capsules; 1 capsule; potassium citrate; on NSF/ANSI 173 | 99 mg | none | $0.19 |
| Nature Made Potassium Gluconate 550 mg100 tablets; 1 tablet; potassium gluconate; on USP Verified | 90 mg | none | $0.04 |
| NOW Potassium Citrate 99 mg180 capsules; 1 capsule; potassium citrate; not on a testing list | 99 mg | none | $0.05 |
| Horbaach Potassium Citrate 275 mg400 capsules; 1 capsule; potassium citrate (275 mg); not on a testing list | 99 mg | none | $0.04 |
How much potassium is in a supplement, and how much magnesium is too much?
NIH's fact sheet on potassium says: "Potassium-only supplements are also available, and most contain up to 99 mg potassium." Adults 19 and older have an Adequate Intake of 3,400 mg a day for men and 2,600 mg for women.
NIH's upper limit for magnesium from supplements is 350 mg a day for adults. At the lowest daily amount on each label, Life Extension gives 250 mg and Nutricost gives 210 mg, both under that limit. The Life Extension label allows up to 2 capsules a day, which is 500 mg of magnesium, over that limit.
Questions people ask
What is the best magnesium supplement with potassium?
Life Extension Potassium with Extend-Release Magnesium. One capsule gives 250 mg of magnesium and 99 mg of potassium for $0.16 a day.
Is there one capsule with both potassium and magnesium?
Yes, two: Life Extension Potassium with Extend-Release Magnesium (250 mg of magnesium and 99 mg of potassium in 1 capsule) and Nutricost Potassium and Magnesium Citrates (210 mg of magnesium and 99 mg of potassium in 2 capsules).
Why do most potassium pills stop at 99 mg?
NIH's fact sheet says: "Many dietary supplement manufacturers and distributors limit the amount of potassium in their products to 99 mg (which is only about 2% of the DV)."
How much potassium do adults need each day?
NIH sets an Adequate Intake of 3,400 mg a day for men and 2,600 mg for women, age 19 and older. A 99 mg capsule is 3.8% of the women's amount and 2.9% of the men's.
Which potassium products are on a testing list?
Two of the six: Thorne Potassium Citrate (NSF/ANSI 173) and Nature Made Potassium Gluconate 550 mg (USP Verified). NSF/ANSI 173 lists Thorne Potassium Citrate as a capsule.
Which product costs the least a day?
Nature Made and Horbaach cost the least a day, $0.04 each.
How we picked
We read each label from the NIH Dietary Supplement Label Database or the supplement facts photo on its Amazon listing on November 12, 2026. We searched NSF/ANSI 173 on November 12, 2026 and USP on November 11, 2026. We priced each pack on November 12, 2026.
Sources
- NSF/ANSI 173 listing: Thorne Potassium Citrate, capsule, read November 12, 2026.
- USP Verified list: Nature Made Potassium Gluconate 550 Mg Tablets, read November 11, 2026.
- NIH Dietary Supplement Label Database labels for Thorne Potassium Citrate (336334), Life Extension Potassium with Extend-Release Magnesium (328641) and Nutricost Potassium and Magnesium Citrates (334873), read November 12, 2026; NOW (313976) and Nature Made (9198) from the same database.
- Supplement facts photo on the Amazon listing for Horbaach Potassium Citrate, read November 12, 2026.
- NIH Office of Dietary Supplements fact sheets on potassium (read November 12, 2026) and magnesium.
- Amazon product listings and prices for the six products and Revive MD, read November 12, 2026 through the Amazon Creators API.