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Magnesium Oxide 400 mg

4.6
★ ★ ★ ★ ★
(66 ratings)
Magnesium 240 mg
Product Image
Score75
A low-cost oxide tablet with weak absorption and an important mismatch between the product name and supplied amount.
How scoring works
Tablet
Quantity:120 Tablet(s) • (120 servings)
Goals:
Stress Relief
Cardiovascular Support
General Health
Energy

Score 75

A low-cost oxide tablet with weak absorption and an important mismatch between the product name and supplied amount.
How scoring works
$7.14($0.05 per serving)
Walmart
$ 7.14
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Analysis

The simple one-tablet formula is inexpensive and provides a moderate stated magnesium amount. It may suit users who primarily want an osmotic bowel effect.

Magnesium oxide is poorly absorbed compared with citrate or chelated forms. The product name references a different amount from the supplied ingredient listing, creating an important clarity problem.

The focused formula has no absorption-supporting form or complementary nutrients. Limited customer volume provides little product-experience evidence, so the label should drive the decision.

Who is it for
  • Budget-focused tablet users
  • Adults seeking occasional bowel support
  • People willing to verify the current label
Best for
  • Low-cost use
  • Simple tablet dosing
  • Occasional stool-softening support

Pros

  • Low serving cost
  • Focused single-mineral formula
  • Moderate listed magnesium amount

Cons

  • Oxide has poor systemic absorption
  • Product name and supplied amount do not match
  • No supportive cofactors

Warnings

  • Verify the package amount because the supplied name and ingredient entry differ
  • Magnesium oxide may cause diarrhea or cramping
  • Impaired kidney function increases magnesium accumulation risk

Nutrient quality

67 High impact

Magnesium oxide provides the main quality signal, while a moderate 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

70 High impact

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

Value for money

73 High impact

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

Report analysis

Goals

Stress Relief
Stress Relief
Impact
High effect
B+ Goal FitC+ Strength of SupportC- CoverageA Formula Quality
Magnesium · 240 mg

A meaningful magnesium amount supports normal nervous-system regulation and may help when low magnesium status worsens stress sensitivity. Its benefit is most likely for users with inadequate intake rather than as a rapid calming agent.

Magnesium oxide has weak systemic absorption. It may also cause loose stools or stomach discomfort in sensitive users. The single-mineral focus provides useful depth but does not address neurotransmitters or the stress-response axis directly.

Study evidence
Magnesium Supportive 13 studies
Cardiovascular Support
Cardiovascular Support
Impact
High effect
B+ Goal FitC Strength of SupportF CoverageA+ Formula Quality
Magnesium · 240 mg

Magnesium can support vascular relaxation and cardiac electrical stability when intake is low. The labeled elemental amount is suitable for general supplementation.

Magnesium oxide has low systemic absorption and may cause loose stools in sensitive users. The focused formula remains less suitable for cardiovascular use than citrate or a well-defined chelate.

Study evidence
Magnesium Supportive 123 studies
General Health
Stress Resilience
General Health
Impact
High effect
B+ Goal FitC- Strength of SupportD- CoverageA- Formula Quality
Magnesium · 240 mg

Magnesium provides foundational support for energy metabolism, muscle function, and normal nerve signaling. The disclosed elemental amount is meaningful for routine supplementation.

Magnesium oxide has low systemic absorption and can be more likely to cause loose stools than better-absorbed forms. The single-ingredient formula is focused, but form quality materially limits its general-health value.

Study evidence
Magnesium Supportive 114 studies
Energy
Energy
Impact
High effect
B- Goal FitC- Strength of SupportD+ CoverageA Formula Quality
Magnesium · 240 mg

Magnesium is required for ATP-dependent reactions and muscle function, but supplementation chiefly helps energy when intake is inadequate. Its metabolic role is well established, while direct fatigue improvement is less predictable in people without deficiency.

The 240 mg elemental magnesium amount meets the configured minimum for meaningful metabolic support. Magnesium oxide is clearly identified but offers poor systemic absorption and can cause loose stools.

Study evidence
Magnesium Supportive 4 studies
Digestive Health
Digestive Health
Impact
Moderate effect
C- Goal FitC- Strength of SupportF CoverageA- Formula Quality
Magnesium · 240 mg

Magnesium oxide provides a clearly stated amount that may support stool softening and motility. The simple formula is easy to assess and most relevant to occasional constipation.

Magnesium oxide is poorly absorbed and may produce loose stools unpredictably rather than offering a well-tolerated motility approach. It does not provide fiber, enzymes, probiotics, or mucosal-support ingredients, so broader digestive coverage is absent.

Study evidence
Magnesium Supportive 50 studies
Heart Health
Healthy Blood Pressure
Heart Health
Impact
Moderate effect
C+ Goal FitD Strength of SupportF CoverageB+ Formula Quality
Magnesium · 240 mg

Magnesium is directly relevant to normal rhythm and vascular tone. The amount is clearly stated and falls within a useful supplemental range.

Magnesium oxide has poor absorption, which limits the practical value of the dose. The lean single-mineral design is focused but does not address other cardiovascular pathways.

Study evidence
Magnesium Supportive 158 studies
Bone Health
Bone Health
Impact
Moderate effect
C Goal FitC- Strength of SupportF CoverageC+ Formula Quality
Magnesium · 240 mg

240 mg of magnesium supports one mineral pathway involved in bone formation and calcium regulation. Magnesium oxide is poorly absorbed compared with citrate or chelated forms.

The single-mineral formula lacks calcium, vitamin D, vitamin K, collagen, and trace-mineral cofactors. Its meaningful labeled amount and simple design provide depth on paper, but form quality limits the likely contribution.

Study evidence
Magnesium Supportive 48 studies

Ingredients

IngredientAmount per serving
Magnesium (Magnesium Oxide)
 240 mg
Adults 18–50 Dairy Free Vegetarian
Report overview
Magnesium (Magnesium Oxide) · 240 mg OverallScore54
F Active Ingredient Quality & BioavailabilityA Dose, Safety & Label TransparencyC Value

Magnesium oxide has low systemic absorption and may be more likely to cause loose stools than better-absorbed forms. 240 mg of elemental magnesium is clearly disclosed and falls in the standard supplemental range; the clean single-mineral design is simple but adds no uptake or bone-health cofactor. The very low serving cost partly offsets the poorly absorbed form.

View ingredientView products
Loading alternative details
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 240 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 240 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 240 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 240 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>Another low-cost candidate, though not cheaper than the original, 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 240 mg amount from Magnesium Oxide.</p>
84 Budget

Potassium + Magnesium

Nutricost
<p>A third low-cost candidate, though not cheaper than the original, 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 240 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 240 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 240 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 240 mg amount from Magnesium Oxide, while the high amount and 30 mg vitamin B6 may reduce suitability for long-term routine use.</p>
Report alternatives

Sources

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

  1. The effect of food, vitamin, or mineral supplements on chronic constipation in adults: A systematic review and meta-analysis of randomized controlled trials.
    van der Schoot A; Creedon A; Whelan K; Dimidi E · Neurogastroenterology and motility · 2023
    Meta-analysis787 participants8 studies pooledDigestive Health forMagnesium
  2. 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
  3. Diagnosis of magnesium-induced diarrhea.
    Fine KD; Santa Ana CA; Fordtran JS · The New England journal of medicine · 1991
    Clinical trial19 participantsDigestive Health forMagnesium
  4. Lactobacillus casei rhamnosus Lcr35 in children with chronic constipation.
    Bu LN; Chang MH; Ni YH; Chen HL; Cheng CC · Pediatrics international : official journal of the Japan Pediatric Society · 2007
    Randomized trial45 participantsDigestive Health forMagnesium
  5. Lactobacillus reuteri DSM 17938 and Magnesium Oxide in Children with Functional Chronic Constipation: A Double-Blind and Randomized Clinical Trial.
    Kubota M; Ito K; Tomimoto K; Kanazaki M; Tsukiyama K; Kubota A; Kuroki H; Fujita M; Vandenplas Y · Nutrients · 2020
    Randomized trial60 participantsDigestive Health forMagnesium
  6. 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
  7. Magnesium-Rich Mineral Water Improves Stool Consistency and Bowel Habits in Healthy Subjects: A Randomized Controlled Trial.
    Yoneda H; Tomita T; Kitano T; Morishita D; Kodani M; Nishii N; Sei H; Eda H; Sato T; Kawai M; Yokoyama Y; Igeta M; Okugawa T; Fukui H; Shinzaki S · Neurogastroenterology and motility · 2026
    Randomized trial40 participantsDigestive Health forMagnesium
  8. 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
  9. 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
  10. Effect of the laxative magnesium oxide on gastrointestinal functional recovery in fast-track colonic resection: a double-blind, placebo-controlled randomized study.
    Andersen J; Christensen H; Pachler JH; Hallin M; Thaysen HV; Kehlet H · Colorectal disease : the official journal of the Association of Coloproctology of Great Britain and Ireland · 2012
    Randomized trial49 participantsDigestive Health forMagnesium
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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
  19. 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
  20. 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
  21. 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
  22. 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
  23. 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 forMagnesium
  24. Red blood cell magnesium and chronic fatigue syndrome.
    Cox IM; Campbell MJ; Dowson D · Lancet (London, England) · 1991
    Randomized trial32 participantsEnergy forMagnesium
  25. Exercise, magnesium and immune function.
    Laires MJ; Monteiro C · Magnesium research · 2008
    Narrative reviewEnergy forMagnesium
  26. 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
  27. 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
  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