Label arithmetic · NIH DSLD 9135
Bronson Potassium & Magnesium Aspartate: 21 mg of magnesium per capsule, 1 capsule a day
21 mg of magnesium per capsule, 1 a day. No US price matched (Nov 2). Inside: salt weight, capsule size.
Bronson Potassium & Magnesium Aspartate declares 21 mg of elemental magnesium per serving as aspartate, which needs 134–280 mg of magnesium aspartate in each capsule, against 545 mg in a size 0 capsule at powder density 0.8 g/mL, the top of the usual 0.6–0.8 range: it fits a size 0 capsule, the smallest of the three sizes compared here. No US retail price matched as of 2026-11-02; 3 of the 25 aspartate labels in this registry have a matched price. NIH DSLD 9135, label dated 2012-06-01.
computed from the filed label
Chart data
| Displayed chart text |
|---|
| 545 mg |
| 730 mg |
| 1,100 mg |
| 134–280 mg of aspartate per capsule |
Data release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · latest price observation 2026-10-19 · chemistry 2026-10-17
Mass: 134–280 mg per capsule · Price: none matched · % DV: 5% vs 5%
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.
Will 21 mg of aspartate actually fit in one capsule, or do I need more than one?
Estimated salt mass versus assumed capsule capacity: Bronson Potassium & Magnesium Aspartate implies 134–280 mg of magnesium aspartate in each capsule to deliver 21 mg of elemental magnesium, against 1,100 mg in the largest standard capsule (size 000) at powder density 0.8 g/mL, the top of the usual 0.6–0.8 range. Verdict: fits size 0, read at the most favourable hydration and the most units per serving.
computed with assumption| Measure | Value |
|---|---|
| Elemental magnesium per serving | 21 mg |
| Units per serving | 1 |
| Magnesium aspartate per serving | 134–280 mg |
| Magnesium aspartate per capsule | 134–280 mg |
| Capsule capacity 0 · 00 · 000 | 545 · 730 · 1,100 mg |
| Verdict | Fits size 0 |
The filed salt can have more than one hydration state (1:1 magnesium aspartate 15.64%; bis(hydrogen aspartate) 8.42%, its dihydrate 7.49%; stoichiometry and hydration unresolved), so the compound mass is a range.
Source · NIH DSLD 9135 · label 2012-06-01; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
How much elemental magnesium is actually in this label's filed magnesium lines?
Bronson Potassium & Magnesium Aspartate files 1 magnesium line in NIH DSLD 9135; the selected primary line declares 21 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 |
|---|---|---|
| 21 mg | aspartate · Magnesium (Form: as magnesium diaspartate) | Primary serving |
Source · NIH DSLD 9135 · label 2012-06-01; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Does this label's aspartate claim hold up, or could the magnesium come from another source?
The label names one magnesium form, aspartate, resolved from the filed magnesium line; at that salt the declaration is within the assumed size 000 capacity at powder density 0.8 g/mL, compared with oxide, the salt richest in magnesium at 60.3%.
computed with assumption| Form named on the label | Elemental fraction | Source |
|---|---|---|
| Magnesium aspartate | 7.5–15.6% | filed magnesium line |
Source · NIH DSLD 9135 · label 2012-06-01; 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; 3 of 25 aspartate labels have one, against a median of none per 100 mg among 0 ranked aspartate offers.
computed| Rank | Label | Per 100 mg | Observed |
|---|
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?
Days per bottle cannot be computed for Bronson Potassium & Magnesium Aspartate as of 2026-11-02: servings per container are not filed.
computed| Measure | Value |
|---|---|
| Net contents as filed | 120 Capsule(s) |
| Serving size as filed | 1 Capsule(s) |
| Servings per container | Not filed as of 2026-11-02 |
| Servings per day in the directions | 1 |
| Days per bottle | Not computable as of 2026-11-02 |
| $ 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 9135 · label 2012-06-01; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does "5% Daily Value" mean here, and does it recompute?
The label declares 5% Daily Value; 21 mg against the 420 mg reference in 21 CFR 101.9 recomputes to 5%, the same within one point.
computed| Group as filed | Declared | Reference | Recomputed |
|---|---|---|---|
| Adults and children 4 or more years of age | 5% | 420 mg | 5% |
Source · NIH DSLD 9135; 21 CFR 101.9 · label 2012-06-01 · release 2026-08-10-f441aa9f · CSV · method
Why does this label contain magnesium stearate, what shell is it, and who is it filed for?
Bronson Potassium & Magnesium Aspartate files 2 other ingredients, including magnesium stearate (reference fraction 4.1% magnesium; no quantity filed, so it is not added to the total) and a gelatin shell, against 15 of 25 aspartate labels that list magnesium stearate.
measured| Entry | Filed ingredient or declaration |
|---|---|
| 1 | Gelatin |
| 2 | Magnesium Stearate |
| Shell | gelatin |
| Target group | Adult (18 - 50 Years) |
Source · NIH DSLD 9135 · label 2012-06-01; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What has research measured about aspartate, and about side effects?
2 studies in the PubMed-checked registry measured outcomes involving aspartate; none reports a gastrointestinal outcome as of 2026-11-02. They measured the salt, not this label.
measured| Year | Study | PubMed |
|---|---|---|
| 2005 | Study of magnesium bioavailability from ten organic and inorganic Mg salts in Mg-depleted rats using a stable isotope approach | 16548135 |
| 2001 | Bioavailability of US commercial magnesium preparations | 11794633 |
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?
Bronson has 0 FDA recall records matched by brand name in the enforcement data queried 2026-10-19. Bronson 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 |
|---|---|---|---|
| No recall record as of 2026-10-19 |
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?
No other brand files the same formulation (ingredients, shell, units and rounded amount) as of 2026-11-02.
computed| Label | Brand | Price per 100 mg |
|---|---|---|
| No cross-brand match as of 2026-11-02 |
Source · NIH DSLD 9135 · label 2012-06-01; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Which labels are closest to this one, with the same salt and dose?
2 labels use the same resolved aspartate within ±10% of this label's 21 mg per unit, compared side by side on price and capsule verdict.
computed| Label | Elemental per unit | Price | Verdict |
|---|---|---|---|
| Solgar Potassium Magnesium Aspartate | 20 mg | No price | Fits size 0 |
| GNC Potassium & Magnesium Aspartate 250 mg | 20 mg | No price | Fits size 0 |
Source · NIH DSLD 9135 · label 2012-06-01; 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 9135 (label 2012-06-01, snapshot 2026-08-10) and the chemistry model of 2026-09-13. 2 gaps remain: No US retail price matched as of 2026-11-02 (barcode 7 16563 25101 7); Servings per container are not filed as of 2026-11-02. The CSV carries the values shown here.
measured| Field | As filed |
|---|---|
| NIH DSLD label | NIH DSLD 9135 |
| Label date | 2012-06-01 |
| Date entered into DSLD | 2012-06-01 |
| Barcode (UPC) as filed | 7 16563 25101 7 |
| Manufacturer | Bronson Laboratories, Inc., Lindon, UT |
| Claim category as filed | All Other |
| Suggested/Recommended/Usage/Directions | SUGGESTED USE: As a dietary supplement, adults 1 capsule daily with a full glass of water with a meal or as directed by a health professional. |
| Storage | Store at room temperature. Protect from light. |
9 additional rows
| Field | As filed |
|---|---|
| Precautions re: Children | Keep out of reach of children. |
| General Statements: All Other Content | Made in USA |
| General Statements: All Other Content | Lot No./Use By |
| General: Product/Version Code | No. 251 |
| FDA Statement of Identity | Dietary Supplement |
| General Statements: All Other Content | BRONSON LABORATORIES |
| General Statements: All Other Content | 083000HF |
| Physical state | Capsule |
| Registry snapshot | 2026-08-10 |
Source · NIH DSLD 9135 · label 2012-06-01; 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.