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High Potency Magnesium 400 mg

4.8
★ ★ ★ ★ ★
(2379 ratings)
Magnesium 400 mg
Product Image
Score80
A convenient, high-amount, low-cost softgel whose oxide form is the main quality and tolerance drawback.
How scoring works
Softgel
Quantity:150 Softgel(s) • (150 servings)
Goals:
Digestive Health
General Health
Energy
Fitness
Heart Health
Bone Health

Score 80

A convenient, high-amount, low-cost softgel whose oxide form is the main quality and tolerance drawback.
How scoring works

Also available as

1 option
60 servings Magnesium 400 mg • 60 Softgel(s) • 60 servings $11.78 ($0.19 per serving)
$22.80($0.15 per serving)
Walmart
$ 22.80
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Analysis

The one-softgel serving provides a substantial magnesium amount with strong convenience and value. Active disclosure is simple and easy to understand.

Magnesium oxide has relatively low systemic absorption compared with citrate or chelated forms. Its bowel effect can be useful for occasional regularity but is a drawback for dependable daily repletion.

The formula does not include a better-absorbed magnesium source or supportive cofactors. Missing daily directions and full inactive ingredients limit complete label assessment.

Who is it for
  • Budget-conscious softgel users
  • Adults seeking a substantial labeled amount
  • People who tolerate magnesium oxide
Best for
  • Low-cost magnesium intake
  • One-softgel convenience
  • Occasional bowel regularity

Pros

  • Substantial disclosed amount
  • Convenient single-softgel serving
  • Favorable serving value

Cons

  • Poorly absorbed oxide form
  • Full excipients and directions are missing
  • No complementary nutrients

Warnings

  • The full oxide serving may cause diarrhea or cramping
  • Sensitive users may find the amount too laxative
  • Impaired kidney function increases magnesium accumulation risk

Nutrient quality

62 Moderate impact

Magnesium oxide provides the main quality signal, while a substantial magnesium amount shapes likely usefulness. Absorption, tolerability, and the formula's focus determine the main trade-off.

Ingredient transparency

87 Highest impact

Active amounts are clearly disclosed, and no proprietary blend hides the total formula. Specific ingredient names make the core actives reasonably easy to assess.

Customer satisfaction

91 Highest impact

The high average rating is supported by substantial review volume. No specific review comments are supplied, so repeated complaints and purpose alignment cannot be confirmed directly.

Value for money

85 Highest impact

Value is favorable for the form quality and disclosed amount. The focused formula avoids paying for token extras, while category competitiveness depends on absorption quality.

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Goals

Digestive Health
Digestive Health
Impact
High effect
B Goal FitA- Strength of SupportD CoverageA Formula Quality
Magnesium · 400 mg

Magnesium may support stool regulation by drawing water into the bowel, but the effect depends strongly on its chemical form. Oxide is poorly absorbed systemically but can retain water in the bowel, which suits short-term motility support.

The single-mineral formula does not support enzymes, the gut barrier, or the microbiome. The 400 mg amount may cause diarrhea, cramping, or electrolyte problems with excessive use.

Study evidence
Magnesium Supportive 50 studies
General Health
General Health
Impact
High effect
A Goal FitC- Strength of SupportD CoverageA- Formula Quality
Magnesium · 400 mg

Magnesium is a foundational mineral involved in energy metabolism, muscle function, and nervous-system regulation, and the label states a substantial amount. The single-mineral design is simple and directly relevant to general health.

Magnesium oxide has poor systemic absorption compared with chelated forms, so the large labeled amount may overstate the amount the body can use. It can also cause loose stools or abdominal discomfort, especially at this supplemental amount.

Study evidence
Magnesium Supportive 114 studies
Energy
Energy
Impact
High effect
A Goal FitC- Strength of SupportD- CoverageB- Formula Quality
Magnesium · 400 mg

Magnesium is essential to ATP production, muscle function, and nerve signaling, so the labeled 400 mg amount appears relevant. Magnesium oxide has poor systemic absorption, which sharply limits its likely contribution to cellular energy.

The single-mineral softgel is focused but covers no alertness or stress-resilience pathway. Magnesium oxide may also loosen stools because much of it remains in the digestive tract.

Study evidence
Magnesium Supportive 4 studies
Fitness
Fitness
Impact
High effect
C Goal FitC Strength of SupportD CoverageA Formula Quality
Magnesium · 400 mg

Magnesium supports muscle contraction and ATP-related metabolism, so it can help fitness when intake or status is inadequate. Direct improvements in performance are less certain for athletes who already get enough magnesium.

The substantial label amount is undermined by poorly absorbed magnesium oxide. The focused formula covers one foundational pathway rather than power, endurance, or muscle repair directly.

Study evidence
Magnesium Disputed 29 studies
Heart Health
Heart Health
Impact
High effect
B- Goal FitD+ Strength of SupportD+ CoverageA Formula Quality
Magnesium · 400 mg

A full magnesium serving supports normal vascular tone, blood-pressure regulation, and cardiac rhythm, especially when dietary intake is low. It remains a single-pathway option rather than a broad cardiovascular formula.

The 400 mg amount is clearly stated and uses magnesium oxide. Oxide has poor systemic absorption despite the high stated amount.

Study evidence
Magnesium Supportive 158 studies
Bone Health
Bone Health
Impact
High effect
B Goal FitC Strength of SupportF CoverageB+ Formula Quality
Magnesium · 400 mg

Magnesium is relevant to bone formation and vitamin D activation, but magnesium oxide is poorly absorbed for systemic use. The stated amount is substantial on the label yet may deliver less usable magnesium than better organic forms.

The formula covers only one bone-related mineral pathway and adds no calcium, vitamin D, vitamin K, or matrix support. Magnesium oxide at this amount may cause diarrhea or abdominal cramping.

Study evidence
Magnesium Supportive 48 studies

Ingredients

IngredientAmount per serving
Calories
10 Calorie(s)
Total Fat
0.5 Gram(s)
Magnesium (Magnesium Oxide)
 400 mg
Gluten Free Adults 18–50
Report overview
Magnesium (Magnesium Oxide) · 400 mg OverallScore52
F Active Ingredient Quality & BioavailabilityA Dose, Safety & Label TransparencyD+ Value
+1

Magnesium oxide supplies a clearly labeled therapeutic amount but has poor systemic absorption. The softgel offers a simple single-mineral format without an absorption cofactor. Its very low serving cost improves affordability but not biological value.

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91 Performance

Krebs Magnesium Potassium Complex

Nature's Way
<p>Magnesium lysinate and malate provide favorable forms at a useful 250 mg amount, with 95 mg potassium citrate for broader mineral support. Compared with the original 400 mg amount from Magnesium Oxide, the form disclosure is clearer and the dose is less aggressive for many users.</p>
88 Performance

Magnesium Bisglycinate Powder

NOW
<p>The pure powder provides 250 mg magnesium bisglycinate in a well-absorbed, adjustable form. Compared with the original 400 mg amount from Magnesium Oxide, the single named form is easier to assess and may be gentler on digestion.</p>
85 Performance

Magnesium Bisglycinate Chelate

Healthy Origins
<p>The clean powder uses TRAACS magnesium bisglycinate at a practical 200 mg elemental amount. Compared with the original 400 mg amount from Magnesium Oxide, it prioritizes absorption quality and moderate dosing, although it may provide less total magnesium.</p>
83 Budget

Magnesium Citrate Pure Powder

Best Naturals
<p>The lower-cost powder provides 210 mg magnesium citrate in an adjustable serving. Compared with the original 400 mg amount from Magnesium Oxide, citrate is clearly identified and generally useful for routine repletion, though it may loosen stools.</p>
80 Budget

Magnesium Caps 500 mg

Life Extension
<p>The lower-cost blend supplies 500 mg magnesium across citrate, succinate, glycinate, and oxide sources. It offers a substantial amount for the cost, but oxide lowers average absorption quality and the high serving may cause diarrhea or cramping compared with the original 400 mg amount from Magnesium Oxide.</p>
84 Budget

Potassium + Magnesium

Nutricost
<p>The lower-cost two-mineral formula supplies 210 mg magnesium citrate with 99 mg potassium citrate. It offers clear mineral forms and practical value, although its magnesium amount may be lower than the original 400 mg amount from Magnesium Oxide.</p>
85 Value

Magnesium Bisglycinate 200 mg

Natural Factors
<p>The focused powder combines 200 mg magnesium bisglycinate with a moderate serving cost and a nonaggressive dose. Compared with the original 400 mg amount from Magnesium Oxide, the clearly named form improves quality-to-cost balance while reducing the chance of dose-related digestive discomfort.</p>
85 Value

Cal/Mag 500 mg/250 mg

NaturesPlus
<p>The formula pairs 250 mg chelated magnesium with 500 mg chelated calcium in an economical serving. It adds useful bone-mineral breadth and clear forms compared with the original 400 mg amount from Magnesium Oxide, though calcium may be unnecessary for users seeking magnesium alone.</p>
81 Value

Ultra-Mag

Source Naturals
<p>The broad blend supplies 400 mg magnesium from citrate, glycinate, malate, succinate, and taurinate forms at a favorable serving cost. Form diversity improves practical value compared with the original 400 mg amount from Magnesium Oxide, while the high amount and 30 mg vitamin B6 may reduce suitability for long-term routine use.</p>
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Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. Long-term outcome after intravenous magnesium sulphate in suspected acute myocardial infarction: the second Leicester Intravenous Magnesium Intervention Trial (LIMIT-2).
    Woods KL; Fletcher S · Lancet (London, England) · 1994
    Randomized trial2,316 participantsGeneral Health forMagnesium
  2. Hospital-Acquired Dysmagnesemia and In-Hospital Mortality.
    Cheungpasitporn W; Thongprayoon C; Chewcharat A; Petnak T; Mao MA; Davis PW; Bathini T; Vallabhajosyula S; Qureshi F; Erickson SB · Medical sciences (Basel, Switzerland) · 2024
    Cohort study26,020 participantsGeneral Health forMagnesium
  3. A Randomized Double-blind Placebo-controlled Trial on the Effect of Magnesium Oxide in Patients With Chronic Constipation.
    Mori S; Tomita T; Fujimura K; Asano H; Ogawa T; Yamasaki T; Kondo T; Kono T; Tozawa K; Oshima T; Fukui H; Kimura T; Watari J; Miwa H · Journal of neurogastroenterology and motility · 2022
    Randomized trial34 participantsDigestive Health forMagnesium
  4. Diagnosis of magnesium-induced diarrhea.
    Fine KD; Santa Ana CA; Fordtran JS · The New England journal of medicine · 1991
    Clinical trial19 participantsDigestive Health forMagnesium
  5. Association between Serum Magnesium and Fractures: A Systematic Review and Meta-Analysis of Observational Studies.
    Dominguez LJ; Veronese N; Ciriminna S; Pérez-Albela JL; Vásquez-López VF; Rodas-Regalado S; Di Bella G; Parisi A; Tagliaferri F; Barbagallo M · Nutrients · 2023
    Meta-analysis119,755 participants4 studies pooledBone Health forMagnesium
  6. Bioabsorbable Magnesium-Based Materials Potential and Safety in Bone Surgery: A Systematic Review.
    Hung CH; Kwok YC; Yip J; Wong HH; Leung YY · Craniomaxillofacial trauma & reconstruction · 2025
    Systematic review386 participants8 studies pooledBone Health forMagnesium
  7. Vascularized bone grafting fixed by biodegradable magnesium screw for treating osteonecrosis of the femoral head.
    Zhao D; Huang S; Lu F; Wang B; Yang L; Qin L; Yang K; Li Y; Li W; Wang W; Tian S; Zhang X; Gao W; Wang Z; Zhang Y; Xie X; Wang J; Li J · Biomaterials · 2016
    Randomized trial48 participantsBone Health forMagnesium
  8. An update on magnesium and bone health.
    Rondanelli M; Faliva MA; Tartara A; Gasparri C; Perna S; Infantino V; Riva A; Petrangolini G; Peroni G · Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine · 2022
    Narrative reviewBone Health forMagnesium
  9. Sex-specific differences in the association of magnesium intake with femoral neck bone mineral density among older adults.
    Wang B; Tan X; Yao X; Zhu Z · Endocrine connections · 2025
    Cross-sectional study1,343 participantsBone Health forMagnesium
  10. Circulating and dietary magnesium and risk of cardiovascular disease: a systematic review and meta-analysis of prospective studies.
    Del Gobbo LC; Imamura F; Wu JH; de Oliveira Otto MC; Chiuve SE; Mozaffarian D · The American journal of clinical nutrition · 2013
    Meta-analysis313,041 participants16 studies pooledCardiovascular Support forMagnesium
  11. Magnesium and the risk of cardiovascular events: a meta-analysis of prospective cohort studies.
    Qu X; Jin F; Hao Y; Li H; Tang T; Wang H; Yan W; Dai K · PloS one · 2013
    Meta-analysis532,979 participants19 studies pooledCardiovascular Support forMagnesium
  12. Quantitative Association Between Serum/Dietary Magnesium and Cardiovascular Disease/Coronary Heart Disease Risk: A Dose-Response Meta-analysis of Prospective Cohort Studies.
    Zhao L; Hu M; Yang L; Xu H; Song W; Qian Y; Zhao M · Journal of cardiovascular pharmacology · 2020
    Meta-analysis544,581 participants18 studies pooledCardiovascular Support Heart Health forMagnesium
  13. Comparative Efficacy of Nutraceuticals on Endothelial Function: A Systematic Review and Network Meta-Analysis.
    Norouzzadeh M; Rashedi MH; Mahdavi-Mazdeh G; Kosari A; Shahinfar H · Current atherosclerosis reports · 2026
    Meta-analysisCardiovascular Support Heart Health forMagnesium
  14. Serum magnesium, mortality, and cardiovascular disease in chronic kidney disease and end-stage renal disease patients: a systematic review and meta-analysis.
    Xiong J; He T; Wang M; Nie L; Zhang Y; Wang Y; Huang Y; Feng B; Zhang J; Zhao J · Journal of nephrology · 2020
    Meta-analysis200,934 participants20 studies pooledCardiovascular Support forMagnesium
  15. Efficacy of oral magnesium therapy in the treatment of chronic constipation in spastic cerebral palsy children: a randomized controlled trial.
    Hassanein SMA; Deifallah SM; Bastawy HA · World journal of pediatrics : WJP · 2021
    Randomized trial100 participantsDigestive Health forMagnesium
  16. Ca:Mg ratio, medium-chain fatty acids, and the gut microbiome.
    Fan L; Zhu X; Sun S; Yu C; Huang X; Ness R; Dugan LL; Shu L; Seidner DL; Murff HJ; Fodor AA; Azcarate-Peril MA; Shrubsole MJ; Dai Q · Clinical nutrition (Edinburgh, Scotland) · 2022
    Randomized trial240 participantsDigestive Health forMagnesium
  17. The Magnesium-Rich Formula for Functional Constipation in Infants: a Randomized Comparator-Controlled Study.
    Benninga MA; MENA Infant Constipation Study Group; Vandenplas Y · Pediatric gastroenterology, hepatology & nutrition · 2022
    Randomized trial286 participantsDigestive Health forMagnesium
  18. Magnesium treatment increases gut microbiome synthesizing vitamin D and inhibiting colorectal cancer: results from a double-blind precision-based randomized placebo-controlled trial.
    Sun E; Zhu X; Ness RM; Murff HJ; Sun S; Yu C; Fan L; Azcarate-Peril MA; Shrubsole MJ; Dai Q · The American journal of clinical nutrition · 2025
    Randomized trial240 participantsDigestive Health forMagnesium
  19. Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: A randomized controlled trial.
    Hausenblas HA; Lynch T; Hooper S; Shrestha A; Rosendale D; Gu J · Sleep medicine: X · 2025
    Randomized trial80 participantsEnergy forMagnesium
  20. Total magnesium intake and risk of frailty in older women.
    Struijk EA; Fung TT; Bischoff-Ferrari HA; Willett WC; Lopez-Garcia E · Journal of cachexia, sarcopenia and muscle · 2024
    Cohort study81,524 participantsEnergy Fitness forMagnesium
  21. Red blood cell magnesium and chronic fatigue syndrome.
    Cox IM; Campbell MJ; Dowson D · Lancet (London, England) · 1991
    Randomized trial32 participantsEnergy forMagnesium
  22. Exercise, magnesium and immune function.
    Laires MJ; Monteiro C · Magnesium research · 2008
    Narrative reviewEnergy forMagnesium
  23. Dietary Magnesium May Be Protective for Aging of Bone and Skeletal Muscle in Middle and Younger Older Age Men and Women: Cross-Sectional Findings from the UK Biobank Cohort.
    Welch AA; Skinner J; Hickson M · Nutrients · 2018
    Cross-sectional study156,575 participantsFitness forMagnesium
  24. Dietary Magnesium Is Positively Associated With Skeletal Muscle Power and Indices of Muscle Mass and May Attenuate the Association Between Circulating C-Reactive Protein and Muscle Mass in Women.
    Welch AA; Kelaiditi E; Jennings A; Steves CJ; Spector TD; MacGregor A · Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research · 2016
    Cross-sectional study2,570 participantsFitness forMagnesium
  25. Nutritional intake as a determinant of high-speed resistance and multicomponent training efficacy on strength in older women at risk of sarcopenia. A randomized clinical trial.
    Polo-Ferrero L; Recio-Rodriguez JI; González-Manzano S; Martín-Vallejo J; Barbero-Iglesias FJ; Montero-Errasquín B; Cruz-Jentoft AJ; Méndez-Sánchez R · Clinical nutrition (Edinburgh, Scotland) · 2025
    Randomized trial80 participantsFitness forMagnesium
  26. Minerals and Sarcopenia in Older Adults: An Updated Systematic Review.
    van Dronkelaar C; Fultinga M; Hummel M; Kruizenga H; Weijs PJM; Tieland M · Journal of the American Medical Directors Association · 2023
    Systematic review45 studies pooledFitness forMagnesium
  27. Perioperative systemic magnesium to minimize postoperative pain: a meta-analysis of randomized controlled trials.
    De Oliveira GS; Castro-Alves LJ; Khan JH; McCarthy RJ · Anesthesiology · 2013
    Meta-analysis1,257 participants20 studies pooledGeneral Health forMagnesium
  28. Association of magnesium sulfate use with mortality in critically ill patients with sepsis: a retrospective propensity score-matched cohort study.
    Gu WJ; Duan XJ; Liu XZ; Cen Y; Tao LY; Lyu J; Yin HY · British journal of anaesthesia · 2023
    Cohort study10,999 participantsGeneral Health forMagnesium
  29. Hypomagnesemia and Mortality in Incident Hemodialysis Patients.
    Li L; Streja E; Rhee CM; Mehrotra R; Soohoo M; Brunelli SM; Kovesdy CP; Kalantar-Zadeh K · American journal of kidney diseases : the official journal of the National Kidney Foundation · 2016
    Cohort study9,359 participantsGeneral Health forMagnesium
  30. The effects of magnesium supplementation on abnormal uterine bleeding, alopecia, quality of life, and acne in women with polycystic ovary syndrome: a randomized clinical trial.
    Jaripur M; Ghasemi-Tehrani H; Askari G; Gholizadeh-Moghaddam M; Clark CCT; Rouhani MH · Reproductive biology and endocrinology : RB&E · 2022
    Randomized trial64 participantsGeneral Health forMagnesium
  31. Effects of magnesium supplementation on improving hyperglycemia, hypercholesterolemia, and hypertension in type 2 diabetes: A pooled analysis of 24 randomized controlled trials.
    Xu L; Li X; Wang X; Xu M · Frontiers in nutrition · 2023
    Meta-analysis1,325 participants24 studies pooledHeart Health forMagnesium
  32. The effect of lowering blood pressure by magnesium supplementation in diabetic hypertensive adults with low serum magnesium levels: a randomized, double-blind, placebo-controlled clinical trial.
    Guerrero-Romero F; Rodríguez-Morán M · Journal of human hypertension · 2009
    Randomized trial82 participantsHeart Health forMagnesium
  33. Positive effects of magnesium supplementation in metabolic syndrome.
    Kisters S; Kisters K; Werner T; Vormann J; Tokmak F; Westhoff T; Gröber U; Predel HG; Reuter H · International journal of clinical pharmacology and therapeutics · 2024
    Randomized trial54 participantsHeart Health forMagnesium
  34. Role of magnesium supplementation in the treatment of depression: A randomized clinical trial.
    Tarleton EK; Littenberg B; MacLean CD; Kennedy AG; Daley C · PloS one · 2017
    Randomized trial126 participantsStress Relief forMagnesium
  35. Effects of Intravenous Esketamine or Magnesium Sulfate on Early Postoperative Negative Emotions and Pain in Patients Undergoing Endoscopic Sinus Surgery: A Randomized Controlled Trial.
    Wang L; Zhou J; Liu Q; Qian K; Wang L; Xie C · Therapeutics and clinical risk management · 2026
    Randomized trial137 participantsStress Relief forMagnesium
  36. Effect of short-term magnesium supplementation on anxiety, depression and sleep quality in patients after open-heart surgery.
    Saba S; Faizi F; Sepandi M; Nehrir B · Magnesium research · 2022
    Non-randomized trial60 participantsStress Relief forMagnesium
  37. Effects of dry needling compared to magnesium infiltration in trigger points for patients with myofascial pain syndrome: a randomized controlled study in Tunisia.
    Dhouibi J; Moncer R; Kalbousi N; Gaddour M; Laayouni S; Ouanes W; Kacem B; Jemni S · Korean journal of family medicine · 2026
    Randomized trial45 participantsStress Relief forMagnesium
  38. Effect of magnesium and vitamin B6 supplementation on mental health and quality of life in stressed healthy adults: Post-hoc analysis of a randomised controlled trial.
    Noah L; Dye L; Bois De Fer B; Mazur A; Pickering G; Pouteau E · Stress and health : journal of the International Society for the Investigation of Stress · 2021
    Randomized trialStress Relief forMagnesium
  39. Magnesium and anabolic hormones in older men.
    Maggio M; Ceda GP; Lauretani F; Cattabiani C; Avantaggiato E; Morganti S; Ablondi F; Bandinelli S; Dominguez LJ; Barbagallo M; Paolisso G; Semba RD; Ferrucci L · International journal of andrology · 2012
    Cohort study399 participantsTestosterone Support forMagnesium
  40. Analysis of the relationship between the blood concentration of several metals, macro- and micronutrients and endocrine disorders associated with male aging.
    Rotter I; Kosik-Bogacka DI; Dołęgowska B; Safranow K; Kuczyńska M; Laszczyńska M · Environmental geochemistry and health · 2017
    Cross-sectional study313 participantsTestosterone Support forMagnesium
  41. Effect of magnesium supplementation in improving hyperandrogenism, hirsutism, and sleep quality in women with polycystic ovary syndrome: A randomized, placebo-controlled clinical trial.
    Gholizadeh-Moghaddam M; Ghasemi-Tehrani H; Askari G; Jaripur M; Clark CCT; Rouhani MH · Health science reports · 2024
    Randomized trial64 participantsTestosterone Support forMagnesium
  42. The effects of trace element supplementation on glycolipid metabolism in PCOS: a systematic review and meta-analysis.
    Yang L; Gao Y; Zhao W; Qi Y; Duo X; Wang H · Frontiers in nutrition · 2025
    Meta-analysis1,600 participants25 studies pooledTestosterone Support forMagnesium
  43. Effects of magnesium supplementation on testosterone levels of athletes and sedentary subjects at rest and after exhaustion.
    Cinar V; Polat Y; Baltaci AK; Mogulkoc R · Biological trace element research · 2011
    Non-randomized trial20 participantsTestosterone Support forMagnesium