Label arithmetic · NIH DSLD 278245
Pure Encapsulations Potassium Magnesium Citrate: 70 mg of magnesium per capsule, 1–2 capsules a day
70 mg of magnesium per capsule; the label's 1–2 capsules a day give 70–140 mg. No US price matched (Nov 2). Inside: salt weight, capsule size.
Pure Encapsulations Potassium Magnesium (Citrate) declares 70 mg of elemental magnesium per serving as citrate, which needs 433–619 mg of magnesium citrate 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; 17 of the 135 citrate labels in this registry have a matched price. NIH DSLD 278245, label dated 2022-11-22.
computed from the filed label
Chart data
| Displayed chart text |
|---|
| 545 mg |
| 730 mg |
| 1,100 mg |
| 433–619 mg of citrate per capsule |
Data release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · latest price observation 2026-10-19 · chemistry 2026-10-17
Mass: 433–619 mg per capsule · Price: none matched · % DV: 17% vs 17%
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 70 mg of citrate actually fit in one capsule, or do I need more than one?
Estimated salt mass versus assumed capsule capacity: Pure Encapsulations Potassium Magnesium (Citrate) implies 433–619 mg of magnesium citrate in each capsule to deliver 70 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 | 70 mg |
| Units per serving | 1 |
| Magnesium citrate per serving | 433–619 mg |
| Magnesium citrate per capsule | 433–619 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 (trimagnesium dicitrate 16.2%; dibasic and hydrated forms as low as 11.3%), so the compound mass is a range.
Source · NIH DSLD 278245 · label 2022-11-22; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
How much elemental magnesium is actually in this label's filed magnesium lines?
Pure Encapsulations Potassium Magnesium (Citrate) files 1 magnesium line in NIH DSLD 278245; the selected primary line declares 70 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 |
|---|---|---|
| 70 mg | Salt not named in this row; magnesium citrate is taken from the label text | Primary serving |
Source · NIH DSLD 278245 · label 2022-11-22; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Does this label's citrate claim hold up, or could the magnesium come from another source?
The label names one magnesium form, citrate, resolved from the full NIH DSLD record text; 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 citrate | 11.3–16.2% | full NIH DSLD record text |
Source · NIH DSLD 278245 · label 2022-11-22; 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 135 citrate labels have one, against a median of $0.1159 per 100 mg among 12 ranked citrate offers.
computed
Chart data
| Displayed chart text |
|---|
| n=12 |
| P25 $0.0843 |
| P75 $0.1469 |
| median $0.1159 |
| Rank | Label | Per 100 mg | Observed |
|---|---|---|---|
| 1 | Best Naturals Magnesium Citrate 200 mg | $0.0344 | 2026-11-02 |
| 2 | Solgar Magnesium Citrate | $0.0607 | 2026-11-02 |
| 3 | LES Labs Magnesium Citrate | $0.0777 | 2026-11-02 |
| 4 | Bluebonnet Magnesium Citrate | $0.0865 | 2026-11-02 |
| 5 | Solaray Magnesium Citrate 400 mg | $0.0868 | 2026-11-02 |
| Median | 12 ranked citrate offers | $0.1159 | 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, Pure Encapsulations Potassium Magnesium (Citrate) lasts 90–180 days: 180 servings against 1–2 servings a day in the filed directions.
computed| Measure | Value |
|---|---|
| Net contents as filed | 180 Capsule(s) |
| Serving size as filed | 1 Capsule(s) |
| Servings per container | 180 |
| Servings per day in the directions | 1–2 |
| Days per bottle | 90–180 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 278245 · label 2022-11-22; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does "17% Daily Value" mean here, and does it recompute?
The label declares 17% Daily Value; 70 mg against the 420 mg reference in 21 CFR 101.9 recomputes to 17%, the same within one point.
computed| Group as filed | Declared | Reference | Recomputed |
|---|---|---|---|
| Adults and children 4 or more years of age | 17% | 420 mg | 17% |
Source · NIH DSLD 278245; 21 CFR 101.9 · label 2022-11-22 · 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?
Pure Encapsulations Potassium Magnesium (Citrate) files 3 other ingredients and a vegetarian shell, and no magnesium stearate, against 43 of 135 citrate labels that list magnesium stearate.
measured| Entry | Filed ingredient or declaration |
|---|---|
| 1 | Cellulose |
| 2 | Water |
| 3 | Ascorbyl Palmitate |
| Shell | vegetarian |
| Target group | Adult (18 - 50 Years) |
| Target group | Gluten Free |
Source · NIH DSLD 278245 · label 2022-11-22; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What has research measured about citrate, and about side effects?
10 studies in the PubMed-checked registry measured outcomes involving citrate; 1 mention gastrointestinal or adverse outcomes. They measured the salt, not this label.
measured| Year | Study | PubMed |
|---|---|---|
| 2025 | Comparing the Bioavailability of Two Seawater-Derived Magnesium Preparations. | 40955524 |
| 2024 | Comparative Clinical Study on Magnesium Absorption and Side Effects After Oral Intake of Microencapsulated Magnesium (MAGSHAPE™ Microcapsules) Versus Other Magnesium Sources. | 39770988 |
| 2022 | Effects of short-term magnesium supplementation on ionized, total magnesium and other relevant electrolytes levels. | 35041150 |
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?
Pure Encapsulations has 2 FDA recall records matched by brand name in the enforcement data queried 2026-10-19. Pure Encapsulations 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-0396-2018 | 2017-12-06 | Product contains undeclared sulfites. | Terminated |
| F-0397-2018 | 2017-12-06 | Product contains undeclared sulfites. | 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 278245 · label 2022-11-22; 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 citrate within ±10% of this label's 70 mg per unit, compared side by side on price and capsule verdict.
computed| Label | Elemental per unit | Price | Verdict |
|---|---|---|---|
| Bio-Tech Pharmacal Magnesium Citrate (DSLD 217402) | 75 mg | No price | Fits size 0 |
| Bio-Tech Pharmacal Magnesium Citrate (DSLD 217403) | 75 mg | No price | Fits size 0 |
Source · NIH DSLD 278245 · label 2022-11-22; 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 278245 (label 2022-11-22, 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 7 66298 00453 2). The CSV carries the values shown here.
measured| Field | As filed |
|---|---|
| NIH DSLD label | NIH DSLD 278245 |
| Scanned label (PDF) | Label 278245 scan |
| Label date | 2022-11-22 |
| Date entered into DSLD | 2022-11-22 |
| Barcode (UPC) as filed | 7 66298 00453 2 |
| Label version · Image difference, same product | NIH DSLD 93265 |
| Label version · Image difference, same product | NIH DSLD 218861 |
| Label version · Image difference, same product | NIH DSLD 187497 |
20 additional rows
| Field | As filed |
|---|---|
| Manufactured by: | Pure Encapsulations, Sudbury, MA |
| Claim category as filed | Nutrient |
| Claim category as filed | All Other |
| Claim category as filed | Structure/Function |
| Storage | Store in a cool, dry place. |
| Suggested/Recommended/Usage/Directions | Recommendations: As a dietary supplement, take 1 capsule, 1-2 times daily, with meals. |
| Precautions re: Pregnant or Nursing or Prescription Medications | Warning: Not to be taken if you have hyperkalemia or abnormal kidney function, or take ACE inhibitors or potassium sparing diuretics. If you are pregnant or lactating, have any health condition or are taking any medication, consult your health professional before use. |
| Precautions re: Children | Keep out of the reach of children. |
| General Statements: All Other Content | Scan to learn about our hypoallergenic supplements |
| Precautions re: All Other | Use only if safety seal is intact. |
| General Statements: All Other Content | Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity. |
| Seals/Symbols | GFCO.org (Gluten-Free Certification Organization) |
| Formulation re: Does NOT Contain | Certified Gluten-Free by the Gluten-Free Certification Organization, www.gluten.org |
| Formulation re: Other | Essential mineral for vascular function and overall health |
| Formulation re: Does NOT Contain | Gluten-free, non-GMO & hypoallergenic |
| Formulation re: Other | Gluten-free, non-GMO & hypoallergenic |
| FDA Statement of Identity | Dietary Supplement |
| FDA Disclaimer Statement | This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. |
| Physical state | Capsule |
| Registry snapshot | 2026-08-10 |
Source · NIH DSLD 278245 · label 2022-11-22; 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.