NOW Magnesium Citrate Review 2026

BUDGET PICK

Magnesium

NOW Magnesium Citrate

★★★★☆ 4.3

Pros

• Lowest cost per serving of any quality magnesium
• Good bioavailability from citrate form
• NOW is a trusted, GMP-certified brand
• Vegan, non-GMO with clean ingredient profile

Cons

• Citrate form can cause loose stools at higher doses
• Less effective for sleep support than glycinate forms

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Quick Verdict

NOW Magnesium Citrate delivers a solid dose of well-absorbed magnesium at the lowest price per serving of any quality product in its class. At roughly $0.08/day, it’s the most budget-friendly way to address magnesium deficiency without resorting to poorly absorbed oxide. The citrate form is a legitimate mid-tier option for general magnesium supplementation, though men prioritizing sleep support or those sensitive to GI effects should consider glycinate instead. 4.3/5.

What Is NOW Magnesium Citrate?

NOW Foods is a family-owned company founded in 1968 that has grown into one of the most respected names in natural products and affordable supplementation. Their Magnesium Citrate capsules have been a staple on health store shelves and Amazon best-seller lists for years, offering a reliable, no-frills magnesium supplement at a price that makes daily supplementation accessible to everyone.

The formula provides 200mg of elemental magnesium per 2-capsule serving, derived from magnesium citrate — a form where magnesium is bound to citric acid. Citrate is considered a mid-tier magnesium form in terms of bioavailability: significantly better than oxide (which absorbs at roughly 4%), but not quite as absorbable as chelated forms like glycinate or lysinate glycinate. Studies suggest citrate absorbs at rates comparable to or slightly below those of amino acid chelates, making it a practical choice for general magnesium repletion when cost is a primary concern.

NOW manufactures this product in their own GMP-certified facilities and the company holds NPA (Natural Products Association) GMP certification. While it lacks USP Verified status, NOW has an excellent reputation for quality control and has a long track record of passing independent third-party testing by organizations like ConsumerLab.

Key Features & Specs

Magnesium Citrate: Where It Fits in the Absorption Hierarchy

Understanding where citrate falls in the magnesium form hierarchy helps you decide if it’s the right choice. Here’s the practical breakdown for men:

Magnesium oxide (cheapest, worst absorption at ~4%, strong laxative effect) sits at the bottom. Magnesium citrate occupies the middle ground — significantly better absorption than oxide, widely available, affordable, and well-studied. Magnesium glycinate and lysinate glycinate (chelated forms) sit at the top for absorption efficiency and stomach comfort, but cost 2–3x more per serving.

Citrate’s mechanism is straightforward: it dissolves well in water (magnesium citrate is highly soluble), and the citric acid component may actually enhance absorption by increasing magnesium’s solubility in the intestinal tract. However, this same solubility means citrate draws water into the bowel through osmosis — which is why magnesium citrate is used in high doses as a laxative for colonoscopy prep. At supplemental doses (200–400mg), this osmotic effect is mild for most people, but men with sensitive GI tracts or those taking higher doses may experience loose stools.

For general magnesium repletion — supporting enzyme function, energy production, muscle function, and nervous system health — citrate is a clinically proven and cost-effective choice. Where it falls short is in targeted applications like sleep support, where glycinate’s calming glycine component gives it a clear advantage.

Pros & Cons

What We Like

• Rock-bottom price for quality magnesium: At approximately $0.08 per day, NOW Magnesium Citrate is the cheapest quality magnesium supplement we recommend. The 240-count bottle provides a full 4-month supply for under $10 in many cases. For men on a tight budget who know they need magnesium, this eliminates the cost barrier entirely.
• Legitimate bioavailability: Citrate is not a gimmick form. Research supports citrate as a meaningfully bioavailable magnesium source — a 2003 study published in Magnesium Research found citrate absorption significantly superior to oxide. You’re not wasting your money on a form that passes through you unabsorbed.
• NOW brand trust: NOW Foods has been in business for over 55 years, manufactures in their own facilities, and consistently passes third-party testing. Their products are regularly reviewed by ConsumerLab and other independent testers. This is not some fly-by-night Amazon brand — NOW has earned its reputation.
• Clean, allergen-friendly formula: Vegan capsules, non-GMO, kosher, and free from the top allergens. The ingredient list is short and free of unnecessary fillers, artificial colors, or preservatives. For a budget product, the formula is impressively clean.

What Could Be Better

• GI effects at higher doses: This is the most important caveat with citrate. At the standard 200mg dose, most men tolerate it without issues. But if you take 400mg or more (which many men need to fully correct deficiency), loose stools become increasingly likely. This osmotic laxative effect is inherent to the citrate form and is the primary reason glycinate is preferred for higher-dose supplementation.
• Not ideal for sleep support: Magnesium glycinate is the go-to form for sleep because of the calming effects of the glycine amino acid. Citrate lacks this component. While magnesium itself supports relaxation and GABA activity, you’re leaving a meaningful sleep benefit on the table by choosing citrate over glycinate. If better sleep is your main goal, this isn’t the right product.

How It Compares

Against Nature Made Magnesium Glycinate, the trade-off is clear: price vs. premium quality. Nature Made costs roughly double per day ($0.17 vs. $0.08), but delivers the glycinate form with USP Verified certification. Glycinate absorbs slightly better, is gentler on the stomach at higher doses, and provides sleep-promoting glycine. If you can afford the extra ~$0.09/day, Nature Made is the better product. If that daily difference adds up over time in your budget, NOW Citrate is a legitimate alternative that still works.

Compared to Doctor’s Best High Absorption Magnesium, NOW Citrate saves you about $0.02/day but gives up the Albion chelated absorption advantage. Doctor’s Best uses a lysinate glycinate chelate that bypasses the mineral absorption bottleneck entirely, offers better GI tolerance at higher doses, and includes the calming amino acids glycine and lysine. For an extra two cents per day, Doctor’s Best is a meaningful upgrade. NOW Citrate only wins this matchup if absolute lowest cost is the priority.

See our full Best Magnesium Supplements for Men 2026 guide for a complete comparison of all our top picks.

Who Should Buy NOW Magnesium Citrate

• Men on a tight supplement budget who want the cheapest quality magnesium available
• Anyone looking for general magnesium repletion (enzyme support, energy production, muscle function) rather than sleep-specific benefits
• Men who tolerate citrate well and don’t experience GI sensitivity at standard doses
• Those who appreciate the NOW brand’s decades-long track record of quality and affordability
• Men who want a simple, clean formula without unnecessary additives

Who Should Skip It

• Men whose primary goal is sleep improvement — Nature Made Glycinate or Doctor’s Best chelated magnesium are significantly better choices for sleep support
• Those who are GI-sensitive or need higher doses (400mg+) — citrate’s osmotic effect becomes increasingly problematic above 200mg
• Men who require USP Verified or other premium third-party certifications
• If you’ve tried citrate magnesium before and experienced loose stools or cramping, chelated glycinate is the form for you

Where to Buy

NOW Magnesium Citrate is one of the most widely available supplements on the market. It’s sold on Amazon, iHerb, Vitacost, Whole Foods, Sprouts, and most health food stores. Amazon Subscribe & Save often drops the price by an additional 5–15%, making an already affordable product even cheaper. The 240-count bottle is the best value option and provides a full 4-month supply.

Frequently Asked Questions

Will magnesium citrate cause diarrhea?

At the standard 200mg dose, most men do not experience significant GI effects. However, citrate does draw water into the intestines through osmosis, and at higher doses (400mg+), loose stools become increasingly common. This is a known property of the citrate form, not a defect of this specific product. If GI comfort is a concern, start with one capsule (100mg) and increase gradually. If problems persist, switch to a glycinate or chelated form.

Can I take NOW Magnesium Citrate for sleep?

Magnesium in any form supports relaxation through GABA receptor modulation and muscle relaxation. However, citrate lacks the glycine amino acid component that makes glycinate particularly effective for sleep. If sleep is your primary reason for taking magnesium, you’ll get better results with a glycinate product. NOW Citrate is a solid choice for general magnesium support, but it’s not optimized for sleep.

Is NOW Foods a trustworthy brand?

Yes. NOW Foods has been in business since 1968, manufactures in their own GMP-certified facilities in Illinois, and has an excellent track record with independent testing organizations like ConsumerLab. They are one of the most audited and tested supplement brands in the natural products industry. While they don’t carry USP certification on this product, their manufacturing quality is well established.

How does citrate compare to oxide for absorption?

Citrate is significantly superior. Magnesium oxide has an estimated bioavailability of roughly 4%, meaning a 400mg oxide supplement delivers only about 16mg of usable magnesium. Citrate absorbs at meaningfully higher rates due to its superior water solubility. A 2003 study in Magnesium Research confirmed that citrate provides significantly greater bioavailability than oxide. Oxide is only cheaper if you ignore how little of it actually gets absorbed.

Should I take it with food?

Taking magnesium citrate with food can improve absorption and reduce the chance of stomach discomfort. Food slows gastric emptying, giving the magnesium more time to be absorbed in the small intestine. That said, citrate is one of the more soluble forms and absorbs reasonably well on an empty stomach. If you experience any GI sensitivity, taking it with a meal should help.

Is 200mg of magnesium citrate enough?

For many men, 200mg supplemental magnesium combined with dietary intake is sufficient to meet the 420mg RDA. If you eat magnesium-rich foods regularly (dark leafy greens, nuts, seeds, whole grains, legumes), 200mg supplemental may fill the gap. If your diet is low in these foods, you might need 400mg supplemental — but be aware that 400mg of citrate is more likely to cause loose stools. In that case, splitting doses (morning and evening) or switching to a chelated form for the higher dose is advisable.

How does NOW Citrate compare to Natural Calm magnesium powder?

Natural Calm is also magnesium citrate, just in a flavored powder form that you mix with water. The active ingredient is essentially the same. NOW’s capsule form is more convenient (no mixing, no taste), more portable, and typically cheaper per serving. Natural Calm’s advantage is the effervescent drink format, which some people find easier to consume and which may absorb slightly faster due to being pre-dissolved. For most men, NOW’s capsule form is the more practical and affordable choice.

Final Rating: 4.3/5

NOW Magnesium Citrate is the budget king of quality magnesium supplementation. At $0.08/day from a trusted brand with decades of manufacturing history, it removes every financial excuse for not supplementing this critical mineral. The citrate form delivers genuine absorption benefits over cheap oxide products, and the clean, vegan formula is free of unnecessary additives. It falls short of our top picks due to the GI sensitivity issue at higher doses and the lack of sleep-specific benefits that glycinate provides. But for straightforward, affordable magnesium coverage, NOW Citrate is a reliable choice that won’t let you down — or empty your wallet.

Last updated: February 2026. We re-evaluate our reviews regularly based on formula changes, pricing, and reader feedback.