{
  "name": "Magnesium Glycinate 400 mg: Label Census and Cost per 400 mg Elemental Magnesium",
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "Verified Supplement Data, https://verifiedsupplementdata.com/magnesium/glycinate-400-mg/",
  "dateModified": "2026-09-21",
  "methodology": "labels sold as magnesium whose product name says glycinate or bisglycinate; Supplement Facts magnesium row is elemental mg per serving; per unit = per serving / units per serving. Every figure was recomputed in two halves split by label-id parity; figures that did not agree within 8 points (shares) or 25% (medians) are not published.",
  "saltWeight": {
    "compound": "magnesium bisglycinate C4H8MgN2O4",
    "molarMass": 172.42,
    "magnesiumAtomicMass": 24.305,
    "magnesiumFractionPct": 14.1,
    "elementalMgIn400MgCompound": 56,
    "compoundMgFor400MgElemental": 2840,
    "note": "The Supplement Facts row named Magnesium is elemental by US regulation; the front label may print either number."
  },
  "limits": {
    "rdaWomenMg": 320,
    "rdaMenMg": 420,
    "supplementalUpperLimitMg": 350,
    "source": "NIH Office of Dietary Supplements, Magnesium Fact Sheet for Health Professionals"
  },
  "labelCensus": {
    "source": "NIH Dietary Supplement Label Database",
    "sourceUrl": "https://dsld.od.nih.gov/",
    "retrievedOn": "2026-08-27",
    "labelsRetrieved": 827,
    "brands": 38,
    "namedGlycinate": {
      "n": 57,
      "medianElementalMgPerServing": 220,
      "p75ElementalMgPerServing": 400,
      "medianElementalMgPerUnit": 100,
      "atLeast400MgPerServingPct": 36.8,
      "blendWithOtherFormsPct": 19.3,
      "validation": {
        "method": "split-half by DSLD label-id parity; shares within 8 points, medians within 25%",
        "checked": 10,
        "held": 5,
        "failed": [
          "p25 per serving",
          "share at least 200 mg per serving",
          "share below 120 mg per serving",
          "share blending magnesium oxide",
          "share needing 2+ units per serving"
        ]
      },
      "notPublished": [
        "p25 per serving",
        "share at least 200 mg per serving",
        "share below 120 mg per serving",
        "share blending magnesium oxide",
        "share needing 2+ units per serving"
      ]
    },
    "anyGlycinateRow": {
      "n": 149,
      "medianElementalMgPerServing": 250,
      "p25ElementalMgPerServing": 200,
      "p75ElementalMgPerServing": 400,
      "medianElementalMgPerUnit": 111,
      "atLeast400MgPerServingPct": 32.9,
      "atLeast200MgPerServingPct": 78.5,
      "below120MgPerServingPct": 10.1,
      "twoPlusUnitsPerServingPct": 78.5,
      "validation": {
        "method": "split-half by DSLD label-id parity; shares within 8 points, medians within 25%",
        "checked": 10,
        "held": 8,
        "failed": [
          "share blending another magnesium form",
          "share blending magnesium oxide"
        ]
      },
      "notPublished": [
        "share blending another magnesium form",
        "share blending magnesium oxide"
      ]
    }
  },
  "costPer400Mg": [
    {
      "name": "BulkSupplements Magnesium Glycinate Powder",
      "brand": "BulkSupplements.com",
      "elementalMgPerServing": 225,
      "servingSize": "1250 mg powder (~1/2 tsp)",
      "servingsPerContainer": 200,
      "elementalMgPerUnit": null,
      "unitsPer400Mg": null,
      "daysOf400MgPerContainer": 112,
      "priceUsd": 19.97,
      "priceVerifiedOn": "2026-09-20",
      "costPer400MgElementalUsd": 0.178,
      "certification": "None",
      "nihDsldId": "310750",
      "availability": "ok"
    },
    {
      "name": "Vitamin Shoppe Magnesium Glycinate 400mg",
      "brand": "The Vitamin Shoppe",
      "elementalMgPerServing": 400,
      "servingSize": "2 tablets",
      "servingsPerContainer": 90,
      "elementalMgPerUnit": 200,
      "unitsPer400Mg": 2,
      "daysOf400MgPerContainer": 90,
      "priceUsd": 19.99,
      "priceVerifiedOn": "2026-09-20",
      "costPer400MgElementalUsd": 0.222,
      "certification": "None",
      "nihDsldId": "208724",
      "availability": "ok"
    },
    {
      "name": "NOW Magnesium Bisglycinate Powder (8 oz)",
      "brand": "NOW Foods",
      "elementalMgPerServing": 250,
      "servingSize": "1 level teaspoon (~2.9 g)",
      "servingsPerContainer": 78,
      "elementalMgPerUnit": null,
      "unitsPer400Mg": null,
      "daysOf400MgPerContainer": 48,
      "priceUsd": 14.69,
      "priceVerifiedOn": "2026-09-20",
      "costPer400MgElementalUsd": 0.301,
      "certification": "NPA GMP Certified, Non-GMO Project Verified",
      "nihDsldId": null,
      "availability": "ok"
    },
    {
      "name": "Nutricost Magnesium Glycinate 210 mg (360 capsules)",
      "brand": "Nutricost",
      "elementalMgPerServing": 210,
      "servingSize": "3 capsules",
      "servingsPerContainer": 120,
      "elementalMgPerUnit": 70,
      "unitsPer400Mg": 6,
      "daysOf400MgPerContainer": 63,
      "priceUsd": 21.95,
      "priceVerifiedOn": "2026-09-20",
      "costPer400MgElementalUsd": 0.348,
      "certification": "None stated (third-party tested claim)",
      "nihDsldId": null,
      "availability": "ok"
    },
    {
      "name": "Nature Made Magnesium Glycinate 200mg",
      "brand": "Nature Made",
      "elementalMgPerServing": 200,
      "servingSize": "1 capsule",
      "servingsPerContainer": 60,
      "elementalMgPerUnit": 200,
      "unitsPer400Mg": 2,
      "daysOf400MgPerContainer": 30,
      "priceUsd": 11.7,
      "priceVerifiedOn": "2026-09-20",
      "costPer400MgElementalUsd": 0.39,
      "certification": "USP Verified",
      "nihDsldId": null,
      "availability": "ok"
    },
    {
      "name": "NOW Magnesium Glycinate 200 mg (240 tablets)",
      "brand": "NOW Foods",
      "elementalMgPerServing": 200,
      "servingSize": "2 tablets",
      "servingsPerContainer": 120,
      "elementalMgPerUnit": 100,
      "unitsPer400Mg": 4,
      "daysOf400MgPerContainer": 60,
      "priceUsd": 26.12,
      "priceVerifiedOn": "2026-09-20",
      "costPer400MgElementalUsd": 0.435,
      "certification": "NPA GMP Certified",
      "nihDsldId": null,
      "availability": "ok"
    },
    {
      "name": "Nature's Bounty High Absorption Magnesium Glycinate 240 mg (120 capsules)",
      "brand": "Nature's Bounty",
      "elementalMgPerServing": 240,
      "servingSize": "2 capsules",
      "servingsPerContainer": 60,
      "elementalMgPerUnit": 120,
      "unitsPer400Mg": 4,
      "daysOf400MgPerContainer": 36,
      "priceUsd": 15.99,
      "priceVerifiedOn": "2026-09-20",
      "costPer400MgElementalUsd": 0.444,
      "certification": "None",
      "nihDsldId": null,
      "availability": "ok"
    },
    {
      "name": "Doctor's Best High Absorption Magnesium",
      "brand": "Doctor's Best",
      "elementalMgPerServing": 200,
      "servingSize": "2 tablets",
      "servingsPerContainer": 60,
      "elementalMgPerUnit": 100,
      "unitsPer400Mg": 4,
      "daysOf400MgPerContainer": 30,
      "priceUsd": 13.99,
      "priceVerifiedOn": "2026-09-20",
      "costPer400MgElementalUsd": 0.466,
      "certification": "None",
      "nihDsldId": null,
      "availability": "ok"
    },
    {
      "name": "KAL Magnesium Glycinate 400",
      "brand": "KAL",
      "elementalMgPerServing": 400,
      "servingSize": "2 tablets",
      "servingsPerContainer": 45,
      "elementalMgPerUnit": 200,
      "unitsPer400Mg": 2,
      "daysOf400MgPerContainer": 45,
      "priceUsd": 24.79,
      "priceVerifiedOn": "2026-09-20",
      "costPer400MgElementalUsd": 0.551,
      "certification": "None",
      "nihDsldId": "253226",
      "availability": "ok"
    },
    {
      "name": "Thorne Magnesium Bisglycinate",
      "brand": "Thorne",
      "elementalMgPerServing": 200,
      "servingSize": "1 capsule",
      "servingsPerContainer": 60,
      "elementalMgPerUnit": 200,
      "unitsPer400Mg": 2,
      "daysOf400MgPerContainer": 30,
      "priceUsd": 26,
      "priceVerifiedOn": "2026-09-20",
      "costPer400MgElementalUsd": 0.867,
      "certification": "NSF Certified for Sport",
      "nihDsldId": null,
      "availability": "ok"
    }
  ]
}