Label arithmetic · NIH DSLD 295968
Source Naturals Magnesium Bis-Glycinate: 100 mg of magnesium per tablet, 4 tablets a day
100 mg of magnesium per tablet; the label's 4 tablets a day give 400 mg. No US price matched (Nov 2). Inside: salt weight, %DV check.
Source Naturals Magnesium Bis-Glycinate declares 200 mg of elemental magnesium per serving as glycinate, which means 1,418–1,691 mg of magnesium glycinate pressed into 2 tablets, compared with 1,100 mg in the largest standard capsule; capsule verdicts do not apply to a tablet. No US retail price matched as of 2026-11-02; 17 of the 73 glycinate labels in this registry have a matched price. NIH DSLD 295968, label dated 2023-08-23.
computed from the filed label
Chart data
| Displayed chart text |
|---|
| gluconate |
| 3,413 |
| orotate |
| 2,751 |
| L-threonate |
| 2,424 |
| taurate |
| 2,242 |
| lactate |
| 1,665 |
| glycerophosphate |
| 1,600 |
| glycinate |
| 1,418 |
| malate |
| 1,287 |
| aspartate |
| 1,279 |
| citrate |
| 1,238 |
| sulfate |
| 991 |
| chloride |
| 783 |
| carbonate |
| 694 |
| hydroxide |
| 480 |
| oxide |
| 332 |
Data release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · latest price observation 2026-10-19 · chemistry 2026-10-17
Mass: 709–845 mg per tablet · Price: none matched · % DV: 50% vs 48%
Elemental: The magnesium itself; the rest of the compound weight is the partner molecule.
Compound: The whole salt, such as magnesium glycinate, that must physically fit in the capsule.
Size 000: The largest standard capsule, about 1,100 mg of powder at 0.8 g/mL, the top of the usual 0.6–0.8 range; size 00 holds about 730 mg and size 0 about 545 mg.
Recompute with your price
Enter the price you paid; the declared amount and servings of this label are prefilled, so the result is the cost per 100 mg of elemental magnesium for your bottle.
Same-salt comparison appears here.
How much glycinate is pressed into one tablet?
Source Naturals Magnesium Bis-Glycinate carries 1,418–1,691 mg of magnesium glycinate per serving for 200 mg of elemental magnesium, against 1,100 mg in the largest standard capsule; capsule capacities do not apply to this tablet or pill.
computed with assumption| Measure | Value |
|---|---|
| Elemental magnesium per serving | 200 mg |
| Units per serving | 2 |
| Magnesium glycinate per serving | 1,418–1,691 mg |
| Magnesium glycinate per tablet | 709–845 mg |
| Capsule capacity 0 · 00 · 000 | 545 · 730 · 1,100 mg |
| Verdict | Capsule sizes do not apply |
The filed salt can have more than one hydration state (bisglycinate; chelate hydration varies by supplier), so the compound mass is a range.
Source · NIH DSLD 295968 · label 2023-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
How much elemental magnesium is actually in this label's filed magnesium lines?
Source Naturals Magnesium Bis-Glycinate files 1 magnesium line in NIH DSLD 295968; the selected primary line declares 200 mg of elemental magnesium per serving, against 0 other rows excluded from the primary amount. A salt named under another nutrient does not turn that nutrient's quantity into elemental magnesium.
measured| Filed amount | Salt or note as filed | Role |
|---|---|---|
| 200 mg | Salt not named in this row; magnesium glycinate is taken from the label text | Primary serving |
Source · NIH DSLD 295968 · label 2023-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Does this label's glycinate claim hold up, or could the magnesium come from another source?
The label names one magnesium form, glycinate, resolved from the full NIH DSLD record text; capsule capacities do not apply to this form, compared with oxide, the salt richest in magnesium at 60.3%.
computed with assumption| Form named on the label | Elemental fraction | Source |
|---|---|---|
| Magnesium glycinate | 11.8–14.1% | full NIH DSLD record text |
Source · NIH DSLD 295968 · label 2023-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Is this a good price for the elemental magnesium I'm actually getting?
No US retail price is matched to this label as of 2026-11-02; 17 of 73 glycinate labels have one, against a median of $0.1889 per 100 mg among 17 ranked glycinate offers.
computed
Chart data
| Displayed chart text |
|---|
| n=17 |
| P25 $0.1338 |
| P75 $0.2216 |
| median $0.1889 |
| Rank | Label | Per 100 mg | Observed |
|---|---|---|---|
| 1 | Amazon Elements Chelated Magnesium 270 mg | $0.0666 | 2026-11-02 |
| 2 | Solgar Chelated Magnesium | $0.0930 | 2026-11-02 |
| 3 | tnvitamins Magnesium Glycinate 300 mg | $0.0962 | 2026-11-02 |
| 4 | New Chapter Magnesium + Ashwagandha | $0.1229 | 2026-11-02 |
| 5 | Windmill Magnesium Glycinate 200 mg | $0.1338 | 2026-11-02 |
| Median | 17 ranked glycinate offers | $0.1889 | 2026-11-02 |
Source · Amazon via licensed data provider; NIH DSLD · unique ASIN × date; prices observed 2026-10-26 to 2026-11-02 · release 2026-08-10-f441aa9f · CSV · method
How many days will this bottle last at the label's own serving, and what does a day cost?
At the label's own serving, Source Naturals Magnesium Bis-Glycinate lasts 15 days: 30 servings against 2 servings a day in the filed directions.
computed| Measure | Value |
|---|---|
| Net contents as filed | 60 Tablet(s) |
| Serving size as filed | 2 Tablet(s) |
| Servings per container | 30 |
| Servings per day in the directions | 2 |
| Days per bottle | 15 days |
| $ per 30 days at one label serving a day | No ranked price as of 2026-11-02 |
| $ per 30 days at 420 mg Daily Value | No ranked price as of 2026-11-02 |
Source · NIH DSLD 295968 · label 2023-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does "50% Daily Value" mean here, and does it recompute?
The label declares 50% Daily Value; 200 mg against the 420 mg reference in 21 CFR 101.9 recomputes to 48%, a difference of 2 points. Labels filed under the earlier 400 mg reference, or with a different filing basis, show gaps of this kind.
computed
Chart data
| Displayed chart text |
|---|
| Declared vs recomputed % |
| DV |
| 48 · 50 |
| Declared vs |
| recomputed % DV |
| Group as filed | Declared | Reference | Recomputed |
|---|---|---|---|
| Adults and children 4 or more years of age | 50% | 420 mg | 48% |
Source · NIH DSLD 295968; 21 CFR 101.9 · label 2023-08-23 · release 2026-08-10-f441aa9f · CSV · method
Why does this label contain magnesium stearate, what shell is it, and who is it filed for?
Source Naturals Magnesium Bis-Glycinate files 5 other ingredients, including magnesium stearate (reference fraction 4.1% magnesium; no quantity filed, so it is not added to the total) and a vegetarian shell, against 28 of 73 glycinate labels that list magnesium stearate.
measured| Entry | Filed ingredient or declaration |
|---|---|
| 1 | Dibasic Calcium Phosphate |
| 2 | Stearic Acid |
| 3 | Modified Cellulose |
| 4 | Silica |
| 5 | Magnesium Stearate |
| Shell | vegetarian |
| Target group | Vegetarian |
| Target group | Adult (18 - 50 Years) |
3 additional rows
| Entry | Filed ingredient or declaration |
|---|---|
| Target group | Gluten Free |
| Target group | Dairy Free |
| Target group | Sugar Free |
Source · NIH DSLD 295968 · label 2023-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What has research measured about glycinate, and about side effects?
6 studies in the PubMed-checked registry measured outcomes involving glycinate; 2 mention gastrointestinal or adverse outcomes. They measured the salt, not this label.
measured| Year | Study | PubMed |
|---|---|---|
| 2024 | Comparative Clinical Study on Magnesium Absorption and Side Effects After Oral Intake of Microencapsulated Magnesium (MAGSHAPE™ Microcapsules) Versus Other Magnesium Sources. | 39770988 |
| 2024 | The bioaccessibility and tolerability of marine-derived sources of magnesium and calcium. | 38608850 |
| 2020 | Dose-Dependent Absorption Profile of Different Magnesium Compounds | 30761462 |
Source · PubMed-checked study registry · registry checked 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Has this brand had FDA recalls or adverse event reports?
Source Naturals has 6 FDA recall records matched by brand name in the enforcement data queried 2026-10-19. Source Naturals has FDA CAERS adverse event reports on record at brand level, as do 143 of 273 brands in this registry; openFDA states that “there is no certainty that the reported event (adverse event) was actually due to the product” and that reports “cannot be used to estimate the incidence of these events.”
measured| Recall | Date | Reason | Status |
|---|---|---|---|
| F-0100-2014 | 2013-11-13 | The firm found small piece of metal fragment in one tablet during its inspection process. | Terminated |
| F-1100-2014 | 2013-12-25 | Dietary Supplements were made with bulk products provided by National Enzyme Company which are currently under recall for chloramphenicol | Terminated |
| F-2178-2017 | 2017-05-10 | Testing of Vitamin D-3 as a result of a consumer complaint found specific lots to have lower concentrations than product specifications of ingredient labeling. | Terminated |
| F-2380-2017 | 2017-07-19 | Dietary supplements contain low levels of undeclared boron | Terminated |
| F-2383-2017 | 2017-07-19 | Dietary supplements contain low levels of undeclared boron | Terminated |
Source · openFDA enforcement and CAERS · queried 2026-10-19 · release 2026-08-10-f441aa9f · CSV · method
Is this the same formula as another brand's, and how do their prices differ?
Same filed formulation as 1 other labels of this brand; no other brand files it as of 2026-11-02.
computed| Label | Brand | Price per 100 mg |
|---|---|---|
| No cross-brand match as of 2026-11-02 |
Source · NIH DSLD 295968 · label 2023-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Which labels are closest to this one, with the same salt and dose?
6 labels use the same resolved glycinate within ±10% of this label's 100 mg per unit, compared side by side on price and capsule verdict.
computed| Label | Elemental per unit | Price | Verdict |
|---|---|---|---|
| Vitamin World Albion Chelated Magnesium 700 mg | 100 mg | No price | Capsule sizes do not apply |
| Kirkman Magnesium Glycinate Bio-Max Series | 100 mg | $47.50 · 2026-11-02 | Needs size 00 |
| Douglas Laboratories Magnesium Glycinate (DSLD 55896) | 100 mg | No price | Capsule sizes do not apply |
| The Vitamin Shoppe Magnesium Glycinate 400 mg | 100 mg | $22.99 · 2026-09-21 | Needs size 00 |
| Douglas Laboratories Magnesium Glycinate (DSLD 230442) | 100 mg | No price | Capsule sizes do not apply |
| Douglas Laboratories Magnesium Glycinate (DSLD 245308) | 100 mg | No price | Capsule sizes do not apply |
Source · NIH DSLD 295968 · label 2023-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Where does this record come from, what is missing, and how do I cite or correct it?
Every value on this page traces to NIH DSLD 295968 (label 2023-08-23, snapshot 2026-08-10) and the chemistry model of 2026-09-13. 1 gap remain: No US retail price matched as of 2026-11-02 (barcode 0 21078 02131 5). The CSV carries the values shown here.
measured| Field | As filed |
|---|---|
| NIH DSLD label | NIH DSLD 295968 |
| Scanned label (PDF) | Label 295968 scan |
| Label date | 2023-08-23 |
| Date entered into DSLD | 2023-08-23 |
| Barcode (UPC) as filed | 0 21078 02131 5 |
| Label version · Package size difference, same product | NIH DSLD 295969 |
| Manufactured for | Source Naturals, Inc., Santa Cruz, CA |
| Claim category as filed | All Other |
16 additional rows
| Field | As filed |
|---|---|
| Claim category as filed | Structure/Function |
| FDA Statement of Identity | Dietary Supplement |
| Formula re: Contains | Superior bioavailable chelate |
| Suggested/Recommended/Usage/Directions | Suggested Use: 2 tablets twice daily. |
| Precautions re: Pregnant or Nursing or Prescription Medications | Caution: If you are pregnant, may become pregnant, or breastfeeding, consult your health care professional before using this product. |
| Storage | Store in a cool, dry place. |
| Precautions re: All Other | Do not use if either tamper-evident seal is broken or missing. |
| Precautions re: Children | Keep out of the reach of children. |
| Formula re: Contains | Magnesium is one of the most important minerals in the body, but an estimated 75% of Americans are magnesium deficient. Magnesium plays a key role in over 300 enzymatic reactions, including supporting cardiovascular, bone, muscle, energy, and neurotransmitter processes. Source Naturals magnesium is attached ("chelated") to the amino acid glycine. The magnesium bis-glycinate combination enables efficient absorption, the glycinate allowing the magnesium to transfer easily across the intestinal wall. Increased absorption means more usable magnesium for your body's needs. |
| Formulation re: Does NOT Contain | Suitable for vegetarians and Hypoallergenic: contains no yeast, dairy, egg, gluten, corn, soy or wheat. Contains no sugar, starch, salt, preservatives, or artificial color, flavor or fragrance. |
| Formulation re: Vegetarian/Vegan | Suitable for vegetarians and Hypoallergenic: contains no yeast, dairy, egg, gluten, corn, soy or wheat. |
| Precautions re: All Other | Suitable for vegetarians and Hypoallergenic: contains no yeast, dairy, egg, gluten, corn, soy or wheat. |
| FDA Disclaimer Statement | These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. |
| Brand IP Statement(s) re: (c), (TM), (SM) | Copyright Source Naturals, Inc. |
| Physical state | Tablet or Pill |
| Registry snapshot | 2026-08-10 |
Source · NIH DSLD 295968 · label 2023-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
6 brand pages linked below contain magnesium labels from the NIH DSLD registry snapshot dated 2026-08-10.