Product Image

Magnesium 500 mg

Nature's Bounty
4.8
★ ★ ★ ★ ★
(8940 ratings)
Magnesium 500 mg
Product Image
Score67
Oxide contains a large mineral proportion but is poorly absorbed compared with citrate, glycinate, or malate. High dose and weak absorption make tolerability a bigger concern than convenience alone suggests.
How scoring works
Quantity:100 Tablet(s) • (100 servings)
Goals:
General Health
Digestive Health
Energy
Heart Health

Score 67

Oxide contains a large mineral proportion but is poorly absorbed compared with citrate, glycinate, or malate. High dose and weak absorption make tolerability a bigger concern than convenience alone suggests.
How scoring works

Also available as

1 option
200 servings Magnesium 500 mg • 200 Tablet(s) • 200 servings $7.47 ($0.03 per serving)
$6.92($0.06 per serving)
Vitacost
$ 8.65
iHerb
$ 7.88
Walmart
$ 6.92
Vitacost
$ 8.65
Amazon
$ 6.92
Report prices

Analysis

A single tablet provides 500 mg of magnesium as magnesium oxide in a very simple formula. Oxide contains a large mineral proportion but is poorly absorbed compared with citrate, glycinate, or malate.

The product may help users seeking digestive effects, but it is less convincing for raising magnesium status or supporting stress and muscle goals. The very low serving cost and one-tablet format are its main advantages.

High dose and weak absorption make tolerability a bigger concern than convenience alone suggests. Choosing a dose that matches personal intake and tolerance is more useful than relying on the headline amount alone.

Who is it for
  • Budget-focused users
  • Adults who specifically want magnesium oxide
  • People comfortable with a high-dose tablet
Best for
  • Low-cost magnesium
  • Simple one-tablet use
  • Users seeking a form with noticeable digestive effects

Pros

  • Provides a clearly labeled magnesium amount
  • Simple one-ingredient formula
  • One-tablet serving is convenient
  • Very low serving cost

Cons

  • Magnesium oxide is poorly absorbed
  • The high amount may favor laxative effects
  • No cofactor supports cellular magnesium use

Warnings

  • The large supplemental magnesium amount may cause loose stools, nausea, or abdominal cramping, especially when taken all at once.
  • Supplemental magnesium can accumulate with significant kidney impairment; use only with medical guidance in that situation.
  • Magnesium can reduce absorption of levothyroxine and tetracycline or quinolone antibiotics, so separate the doses as directed by a pharmacist.

Nutrient quality

62 Moderate impact

Magnesium oxide has low systemic absorption and is more likely to act in the digestive tract. The 500 mg amount may cause diarrhea or cramping, especially in poorly absorbed forms.

.

Ingredient transparency

81 Highest impact

The elemental amount is clearly stated and no proprietary blend hides the dose. Missing other ingredients and complete intake directions leave important label details unresolved.

.

Customer satisfaction

66 High impact

The supplied average rating is strong and the rating volume provides an aggregate signal. No comment-level evidence is provided to assess recurring complaints or confirm how experience matches the intended purpose.

.

Value for money

55 Moderate impact

Weak absorption or uncertain elemental yield limits effective value. The supplied active formula is not inflated by obvious low-value extras.

.
Report analysis

Goals

General Health
General Health
Impact
High effect
A Goal FitC- Strength of SupportD CoverageB+ Formula Quality
Magnesium · 500 mg

Magnesium is central to energy metabolism, nerve signaling, and muscle function. The clearly labeled 500 mg amount is substantial but relies on poorly absorbed magnesium oxide.

A high oxide dose may be more likely to cause digestive effects than to efficiently restore systemic magnesium. The simple formula offers narrow support and is less compelling than an absorbable magnesium form.

Study evidence
Magnesium Supportive 114 studies
Digestive Health
Digestive Health
Impact
High effect
C+ Goal FitB Strength of SupportD- CoverageA Formula Quality
Magnesium · 500 mg

Magnesium oxide is poorly absorbed systemically, but that same property can draw water into the bowel and support occasional stool passage. The clearly stated 500 mg amount is large enough to produce a noticeable laxative effect.

The formula does not support gut barrier, enzyme, or microbiome pathways, so its digestive role is narrow. The full amount may cause diarrhea, abdominal cramping, or urgency, especially in people who are sensitive to magnesium salts.

Study evidence
Magnesium Supportive 50 studies
Energy
Energy
Impact
High effect
A- Goal FitC- Strength of SupportD- CoverageA Formula Quality
Magnesium · 500 mg

Magnesium is essential for ATP production, but the oxide form is poorly suited to restoring systemic levels. Evidence supports magnesium for normal energy metabolism, especially when deficiency is present.

The listed elemental amount is substantial, though poor absorption limits its effective contribution. Magnesium oxide is clearly disclosed but has low systemic absorption and may cause digestive effects.

Study evidence
Magnesium Supportive 4 studies
Heart Health
Heart Health
Impact
High effect
B Goal FitD+ Strength of SupportC- CoverageA Formula Quality
Magnesium · 500 mg

Magnesium at 500 mg may support heart rhythm, vascular tone, and blood-pressure regulation when intake is inadequate. The elemental amount is clearly stated and provides substantial single-pathway support.

Magnesium oxide is poorly absorbed and may be harder on digestion than preferred forms. The substantial supplemental amount may cause diarrhea or abdominal cramping.

Study evidence
Magnesium Supportive 158 studies
Bone Health
Bone Health
Impact
Moderate effect
B- Goal FitC- Strength of SupportD CoverageB- Formula Quality
Magnesium · 500 mg

Magnesium is a relevant bone mineral and supports vitamin D activation and normal mineral regulation. The amount is substantial, but magnesium oxide has relatively poor absorption.

No calcium, vitamin D, vitamin K, trace-mineral cofactors, or collagen are included to cover other skeletal needs. The large magnesium oxide amount commonly causes diarrhea, cramping, or urgency and may be poorly suited to sensitive users.

Study evidence
Magnesium Supportive 48 studies
Cardiovascular Support
Cardiovascular Support
Impact
Moderate effect
B Goal FitD- Strength of SupportD- CoverageA Formula Quality
Magnesium · 500 mg

Magnesium is relevant to vascular relaxation and stable cardiac electrical activity. The elemental amount is clearly disclosed and gives the product a focused purpose.

Magnesium oxide is poorly absorbed compared with organic forms and the large amount may cause digestive upset. The narrow formula also leaves lipid, endothelial, and arterial-calcium pathways unaddressed.

Study evidence
Magnesium Supportive 123 studies

Ingredients

IngredientAmount per serving
Magnesium (Magnesium Oxide)
 500 mg
Gluten Free Adults 18–50 Dairy Free Sugar Free
Report overview
Magnesium (Magnesium Oxide) · 500 mg OverallScore45
F Active Ingredient Quality & BioavailabilityB Dose, Safety & Label TransparencyD- Value

Magnesium oxide provides a clearly labeled amount at a very low cost. Its poor absorption limits usefulness for raising systemic magnesium, and the dose may be harder on digestion. The simple formula lacks a cofactor that could improve cellular use.

View ingredientView products
Loading alternative details
91 Performance

Krebs Magnesium Potassium Complex

Nature's Way
Magnesium lysinate and malate provide favorable forms at a useful amount, with a modest potassium contribution. The better-absorbed form is more suitable for systemic magnesium replenishment than the original’s weaker form. The formula remains focused rather than comprehensive.
88 Performance

Magnesium Bisglycinate Powder

NOW
Magnesium bisglycinate supplies a well-absorbed form at a practical amount in an adjustable powder. The better-absorbed form is more suitable for systemic magnesium replenishment than the original’s weaker form. The single-mineral design does not address needs beyond magnesium.
85 Performance

Magnesium Bisglycinate 200 mg

Natural Factors
Magnesium bisglycinate provides a highly absorbable form at a moderate amount suited to routine use. The better-absorbed form is more suitable for systemic magnesium replenishment than the original’s weaker form. The focused formula offers no additional electrolyte or relaxation ingredients.
83 Budget

Magnesium Citrate Pure Powder

Best Naturals
Magnesium citrate in an adjustable powder provides useful absorption with a clearly stated amount. Its lower serving cost improves affordability, while citrate may loosen stools in sensitive users.
70 Budget

Magnesium Caps 500 mg

Life Extension
Citrate, succinate, and named glycinate broaden the magnesium forms in a very economical capsule. No eligible candidate in this slot is cheaper than the original; the oxide portion lowers average absorption, and the large amount may cause diarrhea or cramping.
74 Budget

Potassium + Magnesium

Nutricost
Magnesium citrate with a modest potassium addition creates a simple two-mineral electrolyte formula. No eligible candidate in this slot is cheaper than the original; potassium is only a supporting amount, and citrate may loosen stools in sensitive users.
80 Value

Magnesium Bisglycinate Chelate

Healthy Origins
TRAACS magnesium bisglycinate combines premium form quality, a useful elemental amount, and a clean powder format. The serving costs more, so the value advantage depends on prioritizing form quality. The formula is narrow, and supplied customer satisfaction is less convincing than its ingredient quality.
78 Value

Magnesium Citrate 420 mg

Nutricost
A substantial magnesium citrate amount offers useful absorption in a focused, economical formula. The serving costs more, so the value advantage depends on prioritizing form quality. The higher amount may loosen stools or cause abdominal discomfort in sensitive users.
77 Value

Magnesium Citrate 200 mg

The Vitamin Shoppe
A moderate magnesium citrate amount provides practical daily supplementation in a simple tablet. The serving costs more, so the value advantage depends on prioritizing form quality. Tablet excipients and complete directions are not supplied, and citrate may affect digestive tolerance.
Report alternatives

Sources

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

  1. Examining the Effects of Supplemental Magnesium on Self-Reported Anxiety and Sleep Quality: A Systematic Review.
    Rawji A; Peltier MR; Mourtzanakis K; Awan S; Rana J; Pothen NJ; Afzal S · Cureus · 2024
    Systematic review15 studies pooledStress Relief forMagnesium
  2. 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
  3. Effects of zinc and magnesium supplements on postpartum depression and anxiety: A randomized controlled clinical trial.
    Fard FE; Mirghafourvand M; Mohammad-Alizadeh Charandabi S; Farshbaf-Khalili A; Javadzadeh Y; Asgharian H · Women & health · 2017
    Randomized trial99 participantsStress Relief forMagnesium
  4. 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
  5. Diagnosis of magnesium-induced diarrhea.
    Fine KD; Santa Ana CA; Fordtran JS · The New England journal of medicine · 1991
    Clinical trial19 participantsDigestive Health forMagnesium
  6. 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
  7. 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
  8. 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
  9. 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
  10. 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
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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
  19. 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
  20. 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
  21. 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
  22. 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
  23. Red blood cell magnesium and chronic fatigue syndrome.
    Cox IM; Campbell MJ; Dowson D · Lancet (London, England) · 1991
    Randomized trial32 participantsEnergy forMagnesium
  24. Exercise, magnesium and immune function.
    Laires MJ; Monteiro C · Magnesium research · 2008
    Narrative reviewEnergy forMagnesium
  25. 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
  26. 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
  27. 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
  28. 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
  29. 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
  30. 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
  31. 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
  32. 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
  33. 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
  34. 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
  35. 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
  36. 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
  37. 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
  38. 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
  39. 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
  40. 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
  41. 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