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Magnesium Gels 400 mg

4.8
★ ★ ★ ★ ★
(516 ratings)
Magnesium 400 mg
Product Image
Score76
The larger bottle offers strong value, but it still relies entirely on poorly absorbed magnesium oxide.
How scoring works
Softgel
Quantity:250 Softgel(s) • (250 servings)
Goals:
General Health
Energy
Heart Health
Cardiovascular Support
Digestive Health

Score 76

The larger bottle offers strong value, but it still relies entirely on poorly absorbed magnesium oxide.
How scoring works
$25.42($0.10 per serving)
iHerb
$ 25.42
Vitacost
$ 25.42
Pure Formulas
$ 25.42
Walmart
$ 27.45
Vitacost
$ 25.42
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Analysis

Magnesium supports normal neuromuscular function and cellular energy production, and the stated amount is substantial. Because the entire amount comes from oxide, useful absorption may be considerably lower than the number on the label suggests.

The softgel format and large bottle suit people who want a long supply with minimal routine complexity. No additional actives distract from the purpose, although there are also no cofactors to add broader support.

Cost per serving is a meaningful advantage in this larger package. That economy must be weighed against oxide being more likely to loosen stools than gentler, better-absorbed forms.

Who is it for
  • Adults wanting a long-lasting magnesium supply
  • Regular users comfortable with magnesium oxide
Best for
  • Low-cost ongoing use
  • Simple single-ingredient routines

Pros

  • Large elemental amount
  • High-count bottle
  • Very low serving cost
  • Straightforward softgel format

Cons

  • Uses only magnesium oxide
  • Limited systemic absorption
  • No complementary nutrients

Warnings

  • The full 400 mg oxide amount can cause diarrhea or cramping, particularly when taken at once.
  • People with impaired kidney function may not clear supplemental magnesium safely.
  • Magnesium can reduce absorption of some antibiotics and thyroid medicine, so follow the prescribed spacing instructions.

Nutrient quality

62 Moderate impact

The elemental amount is meaningful and the formula is very focused. Magnesium oxide has weak absorption and the substantial serving may cause digestive effects.

Ingredient transparency

86 Highest impact

The magnesium form and elemental amount are stated clearly without a hidden blend. Detailed intake directions and non-active ingredients are not included in the supplied facts.

Customer satisfaction

69 High impact

The aggregate satisfaction metric is strong and supported by a useful volume of ratings. Specific firsthand feedback is absent, so recurring complaints and purpose fit cannot be assessed.

Value for money

86 Highest impact

Low serving cost supports good basic value. Poorly absorbed oxide limits quality and makes the product less competitive for systemic magnesium support.

Report analysis

Goals

General Health
Impact
High effect
A Goal FitB- Strength of SupportD CoverageB+ Formula Quality
Magnesium · 400 mg

Magnesium is a foundational mineral that supports energy production, nerve signaling, muscle function, and many enzyme systems. The clearly stated 400 mg amount reaches a substantial elemental level.

Magnesium oxide has low systemic absorption, which limits how much of the strong label amount may be useful for general nutritional support. The focused formula avoids a weak multi-ingredient blend but provides no additional pathways or complementary cofactors.

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

Magnesium supplies a substantial amount of an essential mineral needed for muscle, nerve, and cellular energy functions. The focused formula is clearly disclosed and has strong foundational relevance.

Magnesium oxide is poorly absorbed compared with citrate, glycinate, or other better forms, so the large label amount may overstate useful delivery. The serving is also likely to cause diarrhea or abdominal cramping in sensitive users.

Study evidence
Magnesium Supportive 4 studies
Heart Health
Impact
High effect
B Goal FitC+ Strength of SupportD CoverageA Formula Quality
Magnesium · 400 mg

Magnesium provides relevant support for normal heart rhythm and vascular tone at a substantial 400 mg amount. Magnesium oxide has lower absorption potential than preferred forms and can be harder on digestion despite the softgel format.

The focused mineral formula offers useful depth but does not address lipids, cardiac energy, or homocysteine. The full serving may cause loose stools or abdominal discomfort in sensitive users.

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

Magnesium supports vascular tone, normal rhythm, and blood-pressure regulation, giving it clear cardiovascular relevance. Benefits are most likely when intake is inadequate rather than as a stand-alone answer to broad heart risk.

The 400 mg amount is substantial, but magnesium oxide is poorly absorbed and more likely to cause loose stools than better forms. The clean single-ingredient design is easy to assess but covers only one cardiovascular pathway.

Study evidence
Magnesium Supportive 123 studies
Digestive Health
Impact
High effect
C+ Goal FitB- Strength of SupportD- CoverageA- Formula Quality
Magnesium · 400 mg

Magnesium oxide may promote bowel movement because much of it stays in the gut. That makes it relevant to occasional constipation but not broader digestive health.

The clearly disclosed amount is substantial and may produce a strong laxative effect. It can also cause diarrhea or abdominal cramping, especially in sensitive users.

Study evidence
Magnesium Supportive 50 studies
Stress Relief
Impact
Moderate effect
C+ Goal FitC Strength of SupportD- CoverageA- Formula Quality
Magnesium · 400 mg

Magnesium supports nerve regulation and may help stress when status is low. The 400 mg amount is useful by weight, but oxide has weak systemic absorption.

The single-softgel formula is clear and free from unrelated actives. Magnesium oxide at this amount may cause loose stools or abdominal discomfort without delivering the benefits of better-absorbed forms.

Study evidence
Magnesium Supportive 13 studies

Ingredients

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

The elemental dose is clearly disclosed and falls within the preferred range. Magnesium oxide has low absorption, which limits its fit for systemic use. The low serving cost partly offsets that weakness.

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Sources

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

  1. 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
  2. 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 participantsFitness Energy forMagnesium
  3. The effect of magnesium supplementation on muscle fitness: a meta-analysis and systematic review.
    Wang R; Chen C; Liu W; Zhou T; Xun P; He K; Chen P · Magnesium research · 2018
    Meta-analysis542 participants14 studies pooledFitness 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. 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. 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
  29. 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
  30. 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
  31. 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
  32. 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
  33. 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
  34. 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
  35. 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
  36. 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
  37. 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
  38. 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
  39. 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
  40. 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
  41. 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
  42. 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
  43. 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
  44. 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