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Extra Strength Magnesium 500 mg

4.8
★ ★ ★ ★ ★
(158 ratings)
Magnesium 500 mg
Product Image
Score66
Magnesium oxide offers poor systemic absorption and may remain in the digestive tract despite the large stated amount. Weak form quality and likely digestive effects outweigh the headline dose for many users.
How scoring works
Tablet
Quantity:100 Tablet(s) • (100 servings)
Goals:
Digestive Health
General Health
Heart Health

Score 66

Magnesium oxide offers poor systemic absorption and may remain in the digestive tract despite the large stated amount. Weak form quality and likely digestive effects outweigh the headline dose for many users.
How scoring works

Also available as

1 option
200 mg • 100 Tablet(s) servings Magnesium 400 mg • 100 Tablet(s) • 50 servings $5.21 ($0.10 per serving)
$7.41($0.07 per serving)
iHerb
$ 7.41
Pure Formulas
$ 8.09
Walmart
$ 15.52
iHerb
$ 7.41
Report prices

Analysis

The tablet supplies 500 mg of magnesium as oxide in a minimal formula. Magnesium oxide offers poor systemic absorption and may remain in the digestive tract despite the large stated amount.

The product has limited appeal for correcting intake but may fit someone intentionally seeking an oxide-based option. A low price and one-tablet serving keep it accessible and simple.

Weak form quality and likely digestive effects outweigh the headline dose for many users. Choosing a dose that matches personal intake and tolerance is more useful than relying on the headline amount alone.

Who is it for
  • Adults seeking an inexpensive magnesium tablet
  • People who knowingly prefer magnesium oxide
  • Users comfortable with a large single serving
Best for
  • Budget supplementation
  • Simple daily tablet use
  • Digestive effects associated with magnesium oxide

Pros

  • Clear 500 mg elemental label
  • Minimal single-ingredient formula
  • Convenient one-tablet serving
  • Low serving cost

Cons

  • Oxide has low absorption potential
  • Large dose may produce cramping or loose stools
  • No absorption-supporting cofactor is included

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.

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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.

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Customer satisfaction

59 Moderate 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.

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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.

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Goals

Digestive Health
Digestive Health
Impact
High effect
B- Goal FitC+ Strength of SupportD CoverageA Formula Quality
Magnesium · 500 mg

Magnesium oxide may loosen stools by drawing water into the bowel, so it can help occasional constipation. The formula does not support the gut barrier, microbiome, digestive enzymes, or mucosal comfort.

The 500 mg amount is substantial, but oxide is poorly absorbed and often causes cramping or diarrhea at this dose. People with impaired kidney function may accumulate magnesium and should not use a high supplemental amount without medical guidance.

Study evidence
Magnesium Supportive 50 studies
General Health
General Health
Impact
High effect
A Goal FitD Strength of SupportD+ CoverageB+ Formula Quality
Magnesium · 500 mg

Magnesium is a foundational nutrient and fits daily health support. The oxide form is poorly absorbed, so the high labeled amount may not translate into strong systemic support.

The dose is above the usual supplemental upper limit and may cause diarrhea or cramping. A lower amount of a better-absorbed magnesium form would generally be easier to use for routine supplementation.

Study evidence
Magnesium Supportive 114 studies
Heart Health
Heart Health
Impact
High effect
B+ Goal FitC- Strength of SupportD- CoverageA- Formula Quality
Magnesium · 500 mg

Magnesium is relevant to vascular tone, blood-pressure regulation, and normal cardiac rhythm. The oxide form absorbs poorly, so a large label amount may not translate into equally strong systemic support.

The single-active design is transparent and avoids unrelated ingredients. A 500 mg magnesium oxide serving may cause diarrhea or abdominal cramping, and impaired kidney function can increase the risk of magnesium accumulation.

Study evidence
Magnesium Supportive 158 studies
Energy
Energy
Impact
Moderate effect
B Goal FitD+ Strength of SupportD- CoverageA- Formula Quality
Magnesium · 500 mg

Magnesium supports ATP production, muscle function, and nerve signaling, and the label supplies a large elemental amount. A single mineral keeps the formula simple.

Magnesium oxide is poorly absorbed, so the high label amount may not translate into strong systemic replenishment. The large oxide serving may instead cause loose stools or other digestive discomfort.

Study evidence
Magnesium Supportive 4 studies
Cardiovascular Support
Cardiovascular Support
Impact
Moderate effect
B Goal FitD- Strength of SupportD- CoverageA+ Formula Quality
Magnesium · 500 mg

Magnesium directly supports vascular tone and normal cardiac electrical activity. The clearly stated amount is substantial, but magnesium oxide has weak systemic absorption.

The formula offers focused mineral support rather than broad cardiovascular coverage. Its high amount may be more likely to cause digestive effects than a better-absorbed form.

Study evidence
Magnesium Supportive 123 studies
Stress Relief
Stress Relief
Impact
Moderate effect
B- Goal FitD- Strength of SupportD CoverageA- Formula Quality
Magnesium · 500 mg

Magnesium is relevant to nervous-system regulation, but the oxide form limits dependable systemic support. The high stated amount does not fully overcome poor absorption and may act more strongly in the digestive tract.

The label is simple and transparent, with one mineral amount in one tablet. A high oxide dose may cause loose stools, while the formula lacks a complementary calming or stress-adaptation pathway.

Study evidence
Magnesium Supportive 13 studies
Testosterone Support
Testosterone Support
Impact
Moderate effect
D Goal FitC Strength of SupportF CoverageA Formula Quality
Magnesium · 500 mg

Magnesium oxide provides a substantial mineral amount, but its relevance to testosterone is mainly through correcting low magnesium status. The oxide form has poor systemic absorption compared with citrate, malate, or chelated magnesium.

The single-mineral formula is focused and clearly labeled. It does not address zinc, vitamin D, stress regulation, or free-testosterone pathways.

Study evidence
Magnesium Disputed 5 studies

Ingredients

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

Magnesium oxide supplies a clear amount at a low cost. Its poor absorption and above-range dose may favor digestive effects over systemic replenishment. No cofactor or specialized processing improves the basic formulation.

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.
76 Budget

Magnesium Caps 500 mg

Life Extension
Citrate, succinate, and named glycinate broaden the magnesium forms in a very economical capsule. Its serving cost is comparable rather than lower; 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.
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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. Diagnosis of magnesium-induced diarrhea.
    Fine KD; Santa Ana CA; Fordtran JS · The New England journal of medicine · 1991
    Clinical trial19 participantsDigestive Health forMagnesium
  3. 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
  4. 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
  5. 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
  6. 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
  7. 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
  8. 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
  9. 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
  10. 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
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. Red blood cell magnesium and chronic fatigue syndrome.
    Cox IM; Campbell MJ; Dowson D · Lancet (London, England) · 1991
    Randomized trial32 participantsEnergy forMagnesium
  18. Exercise, magnesium and immune function.
    Laires MJ; Monteiro C · Magnesium research · 2008
    Narrative reviewEnergy forMagnesium
  19. 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
  20. 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
  21. 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
  22. 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
  23. 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
  24. 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
  25. 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
  26. 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
  27. 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
  28. 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
  29. 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
  30. 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
  31. 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
  32. 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
  33. 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
  34. 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
  35. 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
  36. 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