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Magnesium Citrate
Bottom line
In our scoring, Magnesium Citrate rates likely effective: the research is fairly solid for magnesium deficiency correction. Our top-scored product is NOW Foods Magnesium Citrate 200mg 250 Tablets (90/100), about $0.10 a day at a clinical dose of 200-400mg elemental magnesium daily. Bottom line: a reasonable pick if it fits your goal. This is our opinion, not medical advice; talk to your clinician before starting.
Citrate is the form we'd reach for first when the goal is topping up magnesium without spending much.
- Evidence
- Likely Effective
- Category
- Vitamins & Minerals
- Best form
- magnesium citrate
- Effective dose
- 200-400mg elemental magnesium daily
- Lab tested
- 5 of 5 products
- Category
- Vitamins & Minerals
- Best form
- magnesium citrate
- Effective dose
- 200-400mg elemental magnesium daily
- Lab tested
- 5 of 5 products
Key takeaways
- →The cheapest well-absorbed form for general magnesium replenishment - far better than oxide, with modest effects on blood pressure, blood sugar, and sleep.
- →Take 200-400mg elemental magnesium daily (citrate is ~16% elemental by weight, so 1,250-2,500mg of the compound). Check the Supplement Facts panel.
- →NOW Foods 250-count ($0.08/day, ConsumerLab approved) is the top pick and the best per-day value; the 100-count NOW bottle ($0.12/day) is the lower-commitment option. Citrate costs ~60-70% less per effective dose than glycinate.
- →The mild laxative effect helps with constipation but hurts if you have IBS-D - use glycinate instead. Avoid in severe (CKD stage 4-5) kidney disease.
What Is Magnesium Citrate?
Citrate is the form we'd reach for first when the goal is topping up magnesium without spending much. In a head-to-head trial, Walker et al. 2003 found citrate pushed serum magnesium meaningfully higher than the cheap oxide form, both right away (p=0.026) and over time (p=0.006), while oxide barely moved the needle past placebo. Citrate absorbs a touch below glycinate, but it does it at 60-70% of the cost. So if your goal is fixing a deficiency or getting the blood pressure and blood sugar benefits on a budget, citrate is hard to beat. Reach for glycinate instead only when sleep, anxiety, or a sensitive gut is what you're really after.
Most of citrate's track record is really magnesium's track record. The blood pressure, blood sugar, sleep, and bone health benefits that show up in reviews apply to magnesium in general when you're correcting a shortfall, not to citrate specifically. What the direct comparison studies add is that citrate absorbs clearly better than the cheap oxide form sitting in a lot of multivitamins.
The one thing that sets citrate apart from glycinate is its mild laxative effect. Citrate pulls water into your intestines and nudges things along (that's the "draws-water-into-the-gut" mechanism). At normal supplement doses (200-400mg elemental, meaning the actual magnesium your body uses), that mostly just means a softer stool. At the much larger doses used for colonoscopy prep (a full bottle at 1,750mg elemental), it becomes a strong osmotic laxative. The upshot: if you're dealing with both low magnesium and constipation, citrate handles both at once. The flip side is that if you run loose or have IBS-D, you'll probably want glycinate instead.
Where citrate gives ground to glycinate: the glycine in glycinate brings its own calming, sleep-friendly effects that citrate doesn't. If you're specifically chasing better sleep or less anxiety on top of a magnesium gap, glycinate stays the better pick. But for everyday, budget-minded supplementation, magnesium citrate is hard to beat.
Does It Work? The Evidence
How A-F grades workMagnesium Citrate earns a Likely Effective rating on the strength of its best-supported uses: magnesium deficiency correction and blood pressure reduction (grade A). The table below grades every claimed benefit on its own, including weaker and more heavily marketed uses, so one strong result never stands in for the rest.
Magnesium deficiency correction
Walker et al. 2003 (Magnesium Research, n=46, 60-day RCT) - citrate produced significantly higher serum magnesium acutely (p=0.026) and chronically (p=0.006) vs. oxide; oxide showed no significant difference from placebo. Blancquaert et al. 2019 (PMID: 31330811) bioavailability assessment confirmed citrate's higher absorption and urinary excretion vs. oxide.
Blood pressure reduction
Zhang et al. 2016 meta-analysis of 34 RCTs (Hypertension) - applies to magnesium supplementation broadly. Afitska et al. 2021 (PMID: 34859788) - 12-week RCT specifically on magnesium citrate in metabolic syndrome subjects showed significant SBP and DBP reduction vs. placebo
Constipation relief
Well-established osmotic laxative mechanism. Used in clinical settings for bowel preparation at high doses.
Sleep quality improvement
Zhang et al. 2021 CARDIA study (PMID: 34883514, n=3,964): highest quartile magnesium intake associated with OR 0.64 for short sleep duration (<7 hours). Abbasi et al. 2012 also supports. Citrate lacks the additional glycine sleep benefit of glycinate form.
Kidney stone prevention
Ettinger et al. 1997 RCT: potassium-magnesium citrate reduced calcium oxalate stone recurrence. Magnesium citrate may reduce urinary oxalate.
Blood glucose and insulin sensitivity improvement
Afitska et al. 2021 (PMID: 34859788) - 12-week RCT in metabolic syndrome subjects; magnesium citrate reduced HbA1c from 6.43% to 6.15% vs. placebo. Magnesium acts as cofactor for insulin receptor autophosphorylation.
Nocturnal leg cramp reduction
Roffe et al. 2002 (PMID: 12011773) - crossover RCT, 300mg elemental magnesium citrate daily; median cramps reduced from 9 (placebo) to 5 (treatment). Low-risk alternative to quinine.
| Grade | Claimed Benefit | Key Studies | Our Verdict |
|---|---|---|---|
| A | Magnesium deficiency correction | Walker et al. 2003 (Magnesium Research, n=46, 60-day RCT) - citrate produced significantly higher serum magnesium acutely (p=0.026) and chronically (p=0.006) vs. oxide; oxide showed no significant difference from placebo. Blancquaert et al. 2019 (PMID: 31330811) bioavailability assessment confirmed citrate's higher absorption and urinary excretion vs. oxide. | Supported |
| A | Blood pressure reduction | Zhang et al. 2016 meta-analysis of 34 RCTs (Hypertension) - applies to magnesium supplementation broadly. Afitska et al. 2021 (PMID: 34859788) - 12-week RCT specifically on magnesium citrate in metabolic syndrome subjects showed significant SBP and DBP reduction vs. placebo | Supported |
| A | Constipation relief | Well-established osmotic laxative mechanism. Used in clinical settings for bowel preparation at high doses. | Supported |
| B | Sleep quality improvement | Zhang et al. 2021 CARDIA study (PMID: 34883514, n=3,964): highest quartile magnesium intake associated with OR 0.64 for short sleep duration (<7 hours). Abbasi et al. 2012 also supports. Citrate lacks the additional glycine sleep benefit of glycinate form. | Early Signal |
| B | Kidney stone prevention | Ettinger et al. 1997 RCT: potassium-magnesium citrate reduced calcium oxalate stone recurrence. Magnesium citrate may reduce urinary oxalate. | Early Signal |
| B | Blood glucose and insulin sensitivity improvement | Afitska et al. 2021 (PMID: 34859788) - 12-week RCT in metabolic syndrome subjects; magnesium citrate reduced HbA1c from 6.43% to 6.15% vs. placebo. Magnesium acts as cofactor for insulin receptor autophosphorylation. | Early Signal |
| B | Nocturnal leg cramp reduction | Roffe et al. 2002 (PMID: 12011773) - crossover RCT, 300mg elemental magnesium citrate daily; median cramps reduced from 9 (placebo) to 5 (treatment). Low-risk alternative to quinine. | Early Signal |
How to Choose: Forms, Doses & What Matters
Clinical dose: 200-400mg elemental magnesium daily; magnesium citrate is ~16% elemental by weight, so 1,250-2,500mg citrate compound delivers the effective dose
Best forms: magnesium citrate
Aim for 200-400mg elemental magnesium daily (elemental means the actual magnesium your body uses, not the weight of the whole compound). One thing to watch: the liquid magnesium citrate oral solutions (such as Amazon Basic Care / Solimo brands) are FDA-regulated OTC saline laxatives, not daily supplements - that osmotic dose clears you out before your body can absorb much of anything. For supplementing, stick to capsules, tablets, or powder. Powders like Natural Calm dissolve in warm water and make it easy to dial in your dose; capsules are out there too if you'd rather. Take it with food if your stomach gets fussy; otherwise food doesn't matter. A good way to start is low (100-200mg elemental) and build up gradually, which keeps the laxative effect in check while your body settles in - and that effect tends to fade as you acclimate. If you run loose, don't take it right before bed. Otherwise, any time of day works fine for general use.
Who Should Take Magnesium Citrate?
Citrate makes the most sense for you if you're low on magnesium and want to fix that without paying for sleep-specific perks you don't need. It's also a smart pick if you've got mild constipation alongside low magnesium, since it handles both at once. Watching your spending? Citrate costs significantly less than glycinate per effective dose (the dose that actually does the work). And if you're prone to kidney stones, citrate's effect on urinary oxalate excretion may work in your favor.
Who Should Avoid It?
Not for everyone
Side Effects & Safety
Product Scores
5 products scored on dosing accuracy, third-party testing, cost per effective dose, and label transparency.
The Scorecard: 5 Products Compared
NOW Foods Magnesium Citrate 200mg 250 Tablets
NOW Foods$24.49 ÷ 245 days at 200mg/day (1 serving × 200mg)
Reliable and affordable with ConsumerLab approval. The tablet form means a few more excipients than capsule options, but nothing concerning.
Prices checked 2026-06-30. Cost shown is per clinically effective daily dose, not per pill.
NOW Foods Magnesium Citrate 200mg 100 Tablets
NOW Foods$12.24 ÷ 102 days at 200mg/day (1 serving × 200mg)
The best value magnesium citrate in a 100-count format from a trusted brand. Single tablet delivers the full 200mg dose, which is simpler than products requiring two capsules.
Prices checked 2026-06-09. Cost shown is per clinically effective daily dose, not per pill.
Pure Encapsulations Magnesium (Citrate)
Pure Encapsulations$34.50 ÷ 91 days at 300mg/day (2 servings × 150mg)
Best choice for people with food sensitivities. Premium quality justifies the price premium for the right user.
Prices checked 2026-06-09. Cost shown is per clinically effective daily dose, not per pill.
Solgar Magnesium Citrate 420mg
Solgar$13.62 ÷ 59 days at 420mg/day (1 serving × 420mg)
Higher elemental dose per serving - useful for those who want to reach 400mg+ without taking multiple products.
Prices checked 2026-06-30. Cost shown is per clinically effective daily dose, not per pill.
Natural Vitality Calm Magnesium Citrate Powder (Unflavored)
Natural Vitality
$20.24 ÷ 60 days at 325mg/day (1 serving × 325mg)
Powder form allows easy dose titration - convenient for those who cannot swallow capsules or want to adjust dose precisely. Get the unflavored version.
Prices checked 2026-06-09. Cost shown is per clinically effective daily dose, not per pill.
Full Comparison
| Category | NOW Foods Magnesium Citrate 200mg 250 Tablets NOW Foods | NOW Foods Magnesium Citrate 200mg 100 Tablets NOW Foods | Pure Encapsulations Magnesium (Citrate) Pure Encapsulations | Solgar Magnesium Citrate 420mg Solgar | Natural Vitality Calm Magnesium Citrate Powder (Unflavored) Natural Vitality |
|---|---|---|---|---|---|
| Brand Score | 90/100Winner | 90/100 | 88/100 | 83/100 | 83/100 |
| Dosing & Form | 25/25Winner | 25/25 | 22/25 | 25/25 | 25/25 |
| Purity | 20/25 | 20/25 | 23/25Winner | 19/25 | 19/25 |
| Value | 23/25Winner | 22/25 | 18/25 | 19/25 | 19/25 |
| Transparency | 22/25 | 23/25 | 25/25Winner | 20/25 | 20/25 |
| Cost/Day | $0.10Winner | $0.12 | $0.38 | $0.23 | $0.34 |
| Dose/Serving | 200mg | 200mg | 150mg | 420mg | 325mg |
| Form | magnesium citrate | magnesium citrate tablet | magnesium citrate | magnesium citrate | magnesium citrate |
| Third-Party Tested | ✓ Yes | ✓ Yes | ✓ Yes | ✓ Yes | ✓ Yes |
| Proprietary Blend | No | No | No | No | No |
Frequently Asked Questions
Magnesium citrate vs glycinate - which should I take?
Glycinate if your goals include sleep improvement, anxiety reduction, or you have a sensitive stomach. Citrate if you want general magnesium supplementation at lower cost and/or also have constipation issues. Citrate is about 60-70% the cost of glycinate per effective dose. Both have good bioavailability. The key distinction is that glycinate's glycine amino acid has its own calming properties that citrate lacks.
Why does magnesium citrate cause loose stools?
Magnesium is poorly absorbed in the lower GI tract and draws water into the intestine through an osmotic mechanism. This softens stools and speeds transit time. At supplemental doses (200-400mg elemental), this effect is usually mild. At the high doses used in colonoscopy prep (~1,750mg elemental in a full 10-oz bottle), it is a powerful laxative. The effect usually diminishes after 1-2 weeks of regular supplementation as your body adjusts.
Is magnesium citrate absorbed as well as magnesium glycinate?
Citrate has better absorption than oxide (the cheap form in many supplements) but slightly lower than glycinate in most comparative studies. A 2003 study by Walker et al. found citrate absorbed significantly better than oxide. The 2019 Uysal et al. study found glycinate (bisglycinate) reached higher serum levels than citrate. The practical difference is modest - both are considered 'bioavailable' forms, and either is vastly superior to magnesium oxide.
What is Natural Calm and is it a good product?
Natural Calm is a popular powdered magnesium citrate supplement in flavored forms. The magnesium citrate itself is a legitimate, well-absorbed form. However, the flavored versions contain added sugars or sweeteners. The unflavored version is cleaner. At ~$0.28/day for 200mg elemental magnesium, it is mid-priced for citrate. Capsule forms from Jarrow or NOW Foods offer comparable magnesium citrate at better value.
Can I take magnesium citrate every day?
Yes. Daily magnesium supplementation is safe for adults with healthy kidneys. The mild laxative effect typically diminishes after 1-2 weeks. The NIH recommends 310-420mg/day total magnesium (dietary + supplemental) for adults. Since most people do not reach this through diet alone, daily supplementation is reasonable long-term.
Related Articles
Sources
- Walker AF, et al. Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnes Res. 2003;16(3):183-191.
- Zhang X, et al. Effects of Magnesium Supplementation on Blood Pressure: A Meta-Analysis of 34 Randomized Controlled Trials. Hypertension. 2016;68(2):324-333.
- Uysal N, et al. Timeline (Bioavailability) of Magnesium Compounds in Hours: Which Magnesium Compound Works Best? Biol Trace Elem Res. 2019;187(1):128-136.
- Ettinger B, et al. Potassium-magnesium citrate is an effective prophylaxis against recurrent calcium oxalate nephrolithiasis. J Urol. 1997;158(6):2069-2073.
- NIH Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals. Updated 2023.
- Blancquaert L, Vervaet C, Derave W. Predicting and testing bioavailability of magnesium supplements. Nutrients. 2019;11(7):1663.
- Afitska K, et al. Magnesium citrate supplementation decreased blood pressure and HbA1c in normomagnesemic subjects with metabolic syndrome: a 12-week, placebo-controlled, double-blinded pilot trial. Magnes Res. 2021;34(4):167-175.
- Roffe C, et al. Randomised, cross-over, placebo controlled trial of magnesium citrate in the treatment of chronic persistent leg cramps. Med Sci Monit. 2002;8(5):CR326-330.
- Zhang Y, et al. Association of magnesium intake with sleep duration and sleep quality: findings from the CARDIA study. Sleep. 2022;45(4):zsab276.
Scores and tiers are our independent opinion, formed by applying a published rubric to label data, third-party certifications, and the research record. They are not statements of objective fact about a product and not a lab test. Where we report a brand-specific fact, it comes from a cited source or a public certification; where verification is missing, we say so rather than assume a result.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before starting any supplement regimen.