Label arithmetic · NIH DSLD 204986
NOW Magnesium & Potassium Aspartate: 125 mg of magnesium per capsule, 2–4 capsules a day
125 mg of magnesium per capsule; the label's 2–4 capsules a day give 250–500 mg. No US price matched (Nov 2). Inside: salt weight, capsule size.
NOW Magnesium & Potassium Aspartate declares 250 mg of elemental magnesium per serving as aspartate, which needs 799–1,669 mg of magnesium aspartate in each capsule, 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: it fits only that size. Price observed 2026-10-26; pack or dose match under review, so no cost per 100 mg is shown. NIH DSLD 204986, label dated 2019-07-24.
computed from the filed label
Chart data
| Displayed chart text |
|---|
| 545 mg |
| 730 mg |
| 1,100 mg |
| 799–1,669 mg of aspartate per capsule |
Data release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · this offer's price observed 2026-10-26 · latest price observation 2026-11-02 · chemistry 2026-10-17
Mass: 799–1,669 mg per capsule · Price: on review · % DV: 60% vs 60%
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 250 mg of aspartate actually fit in one capsule, or do I need more than one?
Estimated salt mass versus assumed capsule capacity: NOW Magnesium & Potassium Aspartate implies 799–1,669 mg of magnesium aspartate in each capsule to deliver 250 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: needs size 000, read at the most favourable hydration and the most units per serving.
computed with assumption| Measure | Value |
|---|---|
| Elemental magnesium per serving | 250 mg |
| Units per serving | 2 |
| Magnesium aspartate per serving | 1,598–3,338 mg |
| Magnesium aspartate per capsule | 799–1,669 mg |
| Capsule capacity 0 · 00 · 000 | 545 · 730 · 1,100 mg |
| Verdict | Needs size 000 |
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 204986 · label 2019-07-24; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
How much elemental magnesium is actually in this label's filed magnesium lines?
NOW Magnesium & Potassium Aspartate files 1 magnesium line in NIH DSLD 204986; the selected primary line declares 250 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 |
|---|---|---|
| 250 mg | aspartate · Magnesium (Form: from Magnesium Aspartate) | Primary serving |
Source · NIH DSLD 204986 · label 2019-07-24; 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 204986 · label 2019-07-24; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Is this a good price for the elemental magnesium I'm actually getting?
NOW Magnesium & Potassium Aspartate was observed at $29.62 on 2026-10-26, but no cost per 100 mg is computed because the offer is a multi-pack (2 packs); against 0 ranked aspartate offers with a median of none.
computed| Rank | Label | Per 100 mg | Observed |
|---|---|---|---|
| On review | NOW Magnesium & Potassium Aspartate (this label) | Not computed | 2026-10-26 |
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, NOW Magnesium & Potassium Aspartate lasts 30–60 days: 60 servings against 1–2 servings a day in the filed directions.
computed| Measure | Value |
|---|---|
| Net contents as filed | 120 Veg Capsule(s) |
| Serving size as filed | 2 Veg Capsule(s) |
| Servings per container | 60 |
| Servings per day in the directions | 1–2 |
| Days per bottle | 30–60 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 204986 · label 2019-07-24; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does "60% Daily Value" mean here, and does it recompute?
The label declares 60% Daily Value; 250 mg against the 420 mg reference in 21 CFR 101.9 recomputes to 60%, the same within one point.
computed| Group as filed | Declared | Reference | Recomputed |
|---|---|---|---|
| Adults and children 4 or more years of age | 60% | 420 mg | 60% |
Source · NIH DSLD 204986; 21 CFR 101.9 · label 2019-07-24 · release 2026-08-10-f441aa9f · CSV · method
Why does this label contain these other ingredients, what shell is it, and who is it filed for?
NOW Magnesium & Potassium Aspartate files 4 other ingredients and a vegetarian shell, and no magnesium stearate, against 15 of 25 aspartate labels that list magnesium stearate.
measured| Entry | Filed ingredient or declaration |
|---|---|
| 1 | Hypromellose |
| 2 | Rice Flour |
| 3 | Stearic Acid |
| 4 | Silicon Dioxide |
| Shell | vegetarian |
| Target group | Vegan |
| Target group | Vegetarian |
| Target group | Adult (18 - 50 Years) |
3 additional rows
| Entry | Filed ingredient or declaration |
|---|---|
| Target group | Kosher |
| Target group | Gluten Free |
| Target group | Dairy Free |
Source · NIH DSLD 204986 · label 2019-07-24; 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?
NOW has 12 FDA recall records matched by brand name in the enforcement data queried 2026-10-19. NOW 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-1726-2013 | 2013-07-31 | It has been determined that this product contains an undeclared ingredient, licorice extract, which contains glycyrrhizin derived from licorice root. | Terminated |
| F-0770-2014 | 2013-12-25 | Firm is recalling dietary supplements containing a raw material which may contain >0.3 ppb chloramphenicol | Terminated |
| F-1537-2014 | 2014-02-26 | Digestive enzyme capsules manufactured by NOW Foods may contain the antibiotic chloramphenicol. | Terminated |
| F-1484-2017 | 2017-02-22 | Product's supplement fact panel incorrectly states that the product contains 75 mg (milligrams) of Molybdenum, when it actually contains 75 mcg (micrograms). | Terminated |
| F-0682-2019 | 2018-12-12 | NOW Health Group Inc. initiated a voluntary recall of NOW s Vitamin B-50 mg 100 Veg Caps product code 0420 because it is mislabeled as Vitamin B-50 mg 100 Veg Caps. | 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?
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 204986 · label 2019-07-24; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Which labels are closest to this one, with the same salt and dose?
1 label use the same resolved aspartate within ±10% of this label's 125 mg per unit, compared side by side on price and capsule verdict.
computed| Label | Elemental per unit | Price | Verdict |
|---|---|---|---|
| Swanson Magnesium Aspartate | 133 mg | $14.84 · 2026-09-11 | Needs size 000 |
Source · NIH DSLD 204986 · label 2019-07-24; 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 204986 (label 2019-07-24, snapshot 2026-08-10), a price observed 2026-10-26 and the chemistry model of 2026-09-13. No data gap remains for the computed fields. The CSV carries the values shown here.
measured| Field | As filed |
|---|---|
| NIH DSLD label | NIH DSLD 204986 |
| Label date | 2019-07-24 |
| Date entered into DSLD | 2019-07-24 |
| Barcode (UPC) as filed | 7 33739 01320 0 |
| Label version · Image difference, same product | NIH DSLD 72121 |
| Label version · Image difference, same product | NIH DSLD 14598 |
| Label version · Image difference, same product | NIH DSLD 51761 |
| Label version · Image difference, same product | NIH DSLD 60662 |
26 additional rows
| Field | As filed |
|---|---|
| Label version · Image difference, same product | NIH DSLD 70618 |
| Manufacturer | NOW Foods, Bloomingdale, IL, USA |
| Claim category as filed | Nutrient |
| Claim category as filed | All Other |
| Claim category as filed | Structure/Function |
| Suggested/Recommended/Usage/Directions | Suggested Usage: Take 2 capsules 1 to 2 times daily. |
| Formula re: Contains | Magnesium and potassium are two minerals that are ubiquitous throughout the body and play fundamental roles in cell and tissue health. They are especially critical for the maintenance of healthy heart and vascular function, the proper transmission of nerve impulses, and the contraction of muscle. Taurine also helps to support neuromuscular and cardiovascular health through its role in the regulation of normal electrolyte and neurotransmitter balance. |
| 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. |
| Precautions re: All Other | Caution: For adults only. |
| Precautions re: Pregnant or Nursing or Prescription Medications | Consult physician if pregnant/nursing, taking medication, or have a medical condition. |
| Precautions re: Children | Keep out of reach of children. |
| General Statements: All Other Content | Heart health Supports healthy heart, muscle and nerve functions |
| Formula re: Contains | With Taurine |
| Seals/Symbols | Non-GMO Triangle K |
| Formulation re: Does NOT Contain | Non-GMO |
| Formula re: Kosher | Triangle K |
| FDA Statement of Identity | A Dietary Supplement |
| Formulation re: Vegetarian/Vegan | Vegetarian/Vegan |
| General Statements: All Other Content | Minerals Family owned since 1968. |
| Formulation re: Does NOT Contain | Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients. |
| Precautions re: Allergies | Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens. |
| General Statements: All Other Content | Natural color variation may occur in this product. |
| Storage | Store in a cool, dry place after opening. |
| Seals/Symbols | GMP Quality Assured |
| Physical state | Capsule |
| Registry snapshot | 2026-08-10 |
Source · NIH DSLD 204986 · label 2019-07-24; 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.