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Magnesium Citrate
Magnesium citrate is the best value for general magnesium replenishment.
- 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 ($0.08/day, ConsumerLab approved) is the top pick; Jarrow Formulas ($0.08/day) is the value 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?
Magnesium citrate is the best value for general magnesium replenishment. Walker et al. 2003 found citrate produced significantly higher serum magnesium than oxide both acutely (p=0.026) and chronically (p=0.006), while oxide was no different from placebo. Absorption is slightly below glycinate but at 60-70% of the cost. If your goal is correcting a deficiency or getting blood pressure and blood sugar benefits on a budget, citrate is hard to beat, buy glycinate instead only if sleep, anxiety, or a sensitive gut is the target.
The evidence base for magnesium citrate is largely shared with magnesium supplementation broadly. The blood pressure, blood sugar, sleep, and bone health benefits seen in reviews apply to magnesium generally when correcting deficiency. Direct comparison studies confirm citrate absorbs significantly better than the cheap oxide form found in many multivitamins.
The one area where citrate distinguishes itself from glycinate is its mild laxative effect. Magnesium citrate draws water into the intestines and stimulates peristalsis. At standard supplemental doses (200-400mg elemental), this effect is mild - just a softer stool for most people. At the high doses used in medical colonoscopy prep (a full bottle at 1,750mg elemental), it is a powerful osmotic laxative. This means citrate is genuinely useful for people who have both magnesium deficiency and constipation issues - two birds, one supplement. It also means people with loose stools or IBS-D should consider glycinate instead.
Where citrate falls short of glycinate: the glycine amino acid in glycinate has independent calming and sleep-promoting effects that citrate lacks. For people specifically targeting sleep quality or anxiety alongside magnesium deficiency, glycinate remains the better choice. But for budget-conscious general supplementation, magnesium citrate is hard to beat.
Does It Work? The Evidence
How A-F grades workMagnesium 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
Take 200-400mg elemental magnesium daily. Important: liquid magnesium citrate oral solutions (such as Amazon Basic Care / Solimo brands) are FDA-regulated OTC saline laxatives, not daily supplements - the osmotic dose causes rapid GI evacuation before systemic absorption can occur. Use only capsule, tablet, or powder forms for supplementation. Powder forms like Natural Calm can be dissolved in warm water and are convenient for titrating dose. Capsule forms are also available. Take with food if you experience any GI discomfort; with or without food otherwise. Start at a lower dose (100-200mg elemental) and increase gradually to minimize any laxative effect while your body adjusts. The laxative effect decreases as your body acclimates. Avoid taking right before bed if you have loose stools. Works well taken at any time of day for general supplementation.
Who Should Take Magnesium Citrate?
People with magnesium deficiency who want cost-effective supplementation without needing sleep-specific benefits. Anyone with mild constipation alongside low magnesium - citrate addresses both. Budget-conscious supplementers (citrate costs significantly less than glycinate per effective dose). People who do not have sleep-specific concerns but want general magnesium support. Those prone to kidney stones may benefit from citrate's effect on urinary oxalate excretion.
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 100 Tablets
NOW Foods$7.49 ÷ 94 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 2026-04-23. Cost shown is per clinically effective daily dose, not per pill.
NOW Foods Magnesium Citrate 200mg
NOW Foods$7.99 ÷ 100 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 2026-03-01. Cost shown is per clinically effective daily dose, not per pill.
Pure Encapsulations Magnesium (Citrate)
Pure Encapsulations$14.90 ÷ 45 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 2026-03-01. Cost shown is per clinically effective daily dose, not per pill.
Natural Vitality Calm Magnesium Citrate Powder (Unflavored)
Natural Vitality
$16.74 ÷ 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 2026-03-01. 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 2026-03-01. Cost shown is per clinically effective daily dose, not per pill.
Full Comparison
| Category | NOW Foods Magnesium Citrate 200mg 100 Tablets NOW Foods | NOW Foods Magnesium Citrate 200mg NOW Foods | Pure Encapsulations Magnesium (Citrate) Pure Encapsulations | Natural Vitality Calm Magnesium Citrate Powder (Unflavored) Natural Vitality | Solgar Magnesium Citrate 420mg Solgar |
|---|---|---|---|---|---|
| Brand Score | 91/100Winner | 90/100 | 89/100 | 84/100 | 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 | 23/25 | 19/25 | 20/25 | 19/25 |
| Transparency | 23/25 | 22/25 | 25/25Winner | 20/25 | 20/25 |
| Cost/Day | $0.08Winner | $0.08 | $0.33 | $0.28 | $0.23 |
| Dose/Serving | 200mg | 200mg | 150mg | 325mg | 420mg |
| Form | magnesium citrate tablet | magnesium citrate | 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.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. The products discussed on this page are not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before starting any supplement regimen.