Best Magnesium Supplements (2026): Tested & Ranked

Magnesium is one of the most important — and most commonly deficient — minerals. It’s involved in over 300 enzymatic reactions, including muscle function, nerve signaling, energy production, and sleep regulation. Surveys consistently show that roughly half of Americans don’t meet the recommended daily intake from food alone.

The problem? There are a dozen different forms of magnesium on the market, wildly different price points, and a lot of confusing marketing. We spent weeks evaluating over 30 products to find the ones actually worth your money.

Our Top Picks at a Glance

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Best Overall Value: Doctor’s Best Magnesium Glycinate

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Doctor’s Best has been a staple in the magnesium space for years, and for good reason. Their chelated magnesium glycinate/lysinate delivers 200mg of elemental magnesium per serving with excellent bioavailability.

The chelated form means the magnesium is bound to the amino acid glycine, which dramatically improves absorption compared to cheaper forms like magnesium oxide. It’s also far less likely to cause the digestive issues that plague citrate and oxide forms.

At roughly $0.12 per serving, this is hard to beat. You’re getting a well-absorbed, well-tolerated magnesium supplement for less than the cost of a stick of gum. The product is third-party tested, and Doctor’s Best has a solid track record for quality.

The downsides are minor: the tablets are fairly large, and you need two per serving to hit 200mg. If you struggle with large pills, consider the Pure Encapsulations capsules instead.

Who it’s for: Anyone looking for a reliable, affordable magnesium glycinate. This is our default recommendation for most people.

Best Premium: Pure Encapsulations Magnesium Glycinate

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Pure Encapsulations is a practitioner-grade brand that takes “clean formulation” to the extreme. Their magnesium glycinate contains no wheat, eggs, tree nuts, peanuts, gluten, artificial sweeteners, colors, or coatings. If you have sensitivities or multiple allergies, this is the safest pick.

The tradeoff is a lower dose per capsule — just 120mg elemental magnesium — meaning you’ll need 2-3 capsules daily for a therapeutic dose. And it’s roughly twice the per-serving cost of Doctor’s Best.

But for the subset of people who react to binders, fillers, or trace allergens in other supplements, Pure Encapsulations is worth every penny. The capsules are also noticeably smaller, which is a real advantage if you hate swallowing tablets.

Who it’s for: People with allergies, sensitivities, or who want the cleanest possible formulation. Also a good choice if your doctor or naturopath recommends practitioner-grade supplements.

Best for Brain Health: Life Extension Neuro-Mag (L-Threonate)

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Magnesium L-threonate is in a class of its own. Developed at MIT, this patented form (sold as Magtein) is the only type of magnesium with published research showing it can increase magnesium levels in the brain by crossing the blood-brain barrier.

A 2010 study in Neuron found that magnesium threonate enhanced learning and memory in both young and aged rats. Human studies have followed, with a 2016 trial in the Journal of Alzheimer’s Disease showing improved cognitive function in older adults with cognitive impairment.

Life Extension’s Neuro-Mag delivers the full clinically studied dose of 2000mg Magtein (144mg elemental magnesium) per three-capsule serving. This is important — many competitors under-dose threonate to cut costs.

The downsides: it’s the most expensive option on this list, the elemental magnesium content is lower than other forms (so it’s not ideal as your sole magnesium source), and you need three capsules per serving.

Who it’s for: Anyone specifically interested in cognitive support, memory, and brain health. Consider pairing it with a glycinate supplement for general magnesium needs.

Best Powder: Natural Vitality CALM

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If you hate swallowing pills, CALM is the answer. This magnesium citrate powder dissolves in water, comes in several flavors (unflavored, raspberry lemon, cherry, and more), and delivers a generous 325mg of elemental magnesium per serving.

Natural Vitality CALM is also one of the few magnesium supplements that’s USP Verified — meaning an independent lab has confirmed that it contains what the label claims, dissolves properly, and was made under good manufacturing practices. That’s a meaningful quality signal.

The main caveat with citrate: it has an osmotic effect in the intestines. At higher doses, it can cause loose stools. This is actually desirable for some people (it doubles as a gentle constipation remedy), but if you have a sensitive stomach, start with half a serving and work up.

Who it’s for: People who prefer powders over pills, those who want a higher-dose option, or anyone who could benefit from citrate’s mild laxative effect.

Worth Considering: BiOptimizers Magnesium Breakthrough

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BiOptimizers takes a different approach: instead of focusing on one form, Magnesium Breakthrough includes seven — glycinate, taurate, malate, orotate, citrate, chelate, and sucrosomial. The theory is that different forms serve different functions, and a blend provides broader benefits.

There’s some logic to this, but also a big problem: it’s a proprietary blend. You get 500mg total, but there’s no way to know how much of each form you’re actually getting. For all we know, it could be 490mg of the cheapest form and 10mg of everything else.

At $0.67 per serving, it’s the most expensive non-threonate option here, and the proprietary blend makes it hard to justify the premium over Doctor’s Best or Pure Encapsulations, where you know exactly what you’re getting.

Who it’s for: People intrigued by the multi-form concept and willing to trust the brand’s formulation choices. We’d generally steer people toward targeted single-form supplements instead.

Buyer’s Guide: How to Choose a Magnesium Supplement

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Understanding Magnesium Forms

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Not all magnesium is created equal. The form determines how well it’s absorbed and what it’s best used for:

• Glycinate — Best all-around form. High bioavailability, gentle on the stomach, supports relaxation and sleep. This is what most people should start with.
• L-Threonate — The only form shown to cross the blood-brain barrier. Best for cognitive support. Lower elemental magnesium, so not ideal as your only source.
• Citrate — Good bioavailability, widely available, affordable. Has an osmotic laxative effect at higher doses. Great in powder form.
• Taurate — Some evidence for cardiovascular support. Less commonly available as a standalone supplement.
• Oxide — Poor bioavailability (only about 4% absorption). Cheap, but you’d need to take much more. Primarily useful as a laxative.

Elemental Magnesium vs. Compound Weight

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This trips people up constantly. When a supplement says “500mg magnesium glycinate,” it doesn’t mean you’re getting 500mg of magnesium. You’re getting 500mg of the magnesium + glycine compound, which yields far less elemental magnesium.

Always look for the elemental magnesium amount on the Supplement Facts panel. That’s the number that matters for meeting your daily needs.

Third-Party Testing

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We strongly prefer supplements that have independent third-party verification:

• USP (United States Pharmacopeia) — Gold standard. Verifies identity, potency, purity, and manufacturing practices.
• NSF International — Another rigorous program, especially their Certified for Sport line.
• ISO-accredited lab testing — Many brands use independent labs even without the USP/NSF seal.

How Much to Take

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The Recommended Dietary Allowance (RDA) for magnesium is:

• Men 19-30: 400mg/day
• Men 31+: 420mg/day
• Women 19-30: 310mg/day
• Women 31+: 320mg/day

Most Americans get 250-350mg from food, so a supplement providing 200-400mg elemental magnesium typically fills the gap. More isn’t always better — the tolerable upper limit from supplements is 350mg/day.

Frequently Asked Questions

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What is the best form of magnesium to take?

Magnesium glycinate is the best form for most people. It has excellent bioavailability, is gentle on the stomach, and supports both general health and relaxation. Magnesium L-threonate is best specifically for cognitive support, while citrate is a good option if you prefer a powder format.

How much magnesium should I take daily?

The RDA for magnesium is 310-420mg per day for adults, depending on age and sex. Many people get 200-300mg from food alone, so a supplement providing 200-400mg of elemental magnesium typically fills the gap. Start with a lower dose and increase gradually.

When is the best time to take magnesium?

Most people benefit from taking magnesium in the evening, as it supports relaxation and sleep quality. However, it can be taken at any time. Consistency matters more than timing. Take it with food to improve absorption and reduce any chance of stomach upset.

Can you take too much magnesium?

Yes. Excessive magnesium from supplements can cause diarrhea, nausea, and cramping. The tolerable upper intake level (UL) from supplements is 350mg per day for adults, though this doesn’t include magnesium from food. Magnesium glycinate is less likely to cause GI issues than citrate or oxide.

What are symptoms of magnesium deficiency?

Common signs include muscle cramps, poor sleep, fatigue, headaches, anxiety, and irregular heartbeat. However, blood tests often miss deficiency because only 1% of magnesium is in the blood. If you suspect deficiency, a red blood cell (RBC) magnesium test is more accurate than a standard serum test.