Label arithmetic · NIH DSLD 202431
Swanson Magnesium 200 mg: 200 mg of magnesium per capsule, 2 capsules a day
200 mg of magnesium per capsule; the label's 2 capsules a day give 400 mg. No US price matched (Nov 2). Inside: salt weight, capsule size.
Swanson Magnesium 200 mg declares 400 mg of elemental magnesium per serving as oxide, which needs 332 mg of magnesium oxide 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; 10 of the 61 oxide labels in this registry have a matched price. NIH DSLD 202431, label dated 2019-11-21.
computed from the filed label
Chart data
| Displayed chart text |
|---|
| 545 mg |
| 730 mg |
| 1,100 mg |
| 332 mg of oxide per capsule |
Data release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · latest price observation 2026-10-19 · chemistry 2026-10-17
Mass: 332 mg per capsule · Price: none matched · % DV: 95% vs 95%
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 400 mg of oxide actually fit in one capsule, or do I need more than one?
Estimated salt mass versus assumed capsule capacity: Swanson Magnesium 200 mg implies 332 mg of magnesium oxide in each capsule to deliver 400 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 | 400 mg |
| Units per serving | 2 |
| Magnesium oxide per serving | 663 mg |
| Magnesium oxide per capsule | 332 mg |
| Capsule capacity 0 · 00 · 000 | 545 · 730 · 1,100 mg |
| Verdict | Fits size 0 |
Source · NIH DSLD 202431 · label 2019-11-21; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
How much elemental magnesium is actually in this label's filed magnesium lines?
Swanson Magnesium 200 mg files 1 magnesium line in NIH DSLD 202431; the selected primary line declares 400 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 |
|---|---|---|
| 400 mg | oxide · Magnesium (Form: as Magnesium Oxide) | Primary serving |
Source · NIH DSLD 202431 · label 2019-11-21; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Does this label's oxide claim hold up, or could the magnesium come from another source?
The label names one magnesium form, oxide, 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 oxide | 60.3% | filed magnesium line |
Source · NIH DSLD 202431 · label 2019-11-21; 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; 10 of 61 oxide labels have one, against a median of $0.0293 per 100 mg among 5 ranked oxide offers.
computed
Chart data
| Displayed chart text |
|---|
| n=5 |
| P25 $0.0258 |
| P75 $0.0356 |
| median $0.0293 |
| Rank | Label | Per 100 mg | Observed |
|---|---|---|---|
| 1 | Nutricost Magnesium Oxide | $0.0148 | 2026-11-02 |
| 2 | tnvitamins Magnesium Oxide 420 mg | $0.0258 | 2026-11-02 |
| 3 | Douglas Laboratories Magnesium Oxide | $0.0293 | 2026-11-02 |
| 4 | Wonder Labs Magnesium Oxide 400 | $0.0356 | 2026-11-02 |
| 5 | Carlson Magnesium Gels 400 mg | $0.0636 | 2026-11-02 |
| Median | 5 ranked oxide offers | $0.0293 | 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, Swanson Magnesium 200 mg lasts 125 days: 125 servings against 1 serving a day in the filed directions.
computed| Measure | Value |
|---|---|
| Net contents as filed | 250 Capsule(s) |
| Serving size as filed | 2 Capsule(s) |
| Servings per container | 125 |
| Servings per day in the directions | 1 |
| Days per bottle | 125 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 202431 · label 2019-11-21; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does "95% Daily Value" mean here, and does it recompute?
The label declares 95% Daily Value; 400 mg against the 420 mg reference in 21 CFR 101.9 recomputes to 95%, the same within one point.
computed| Group as filed | Declared | Reference | Recomputed |
|---|---|---|---|
| Adults and children 4 or more years of age | 95% | 420 mg | 95% |
Source · NIH DSLD 202431; 21 CFR 101.9 · label 2019-11-21 · release 2026-08-10-f441aa9f · CSV · method
Why does this label contain magnesium stearate, what shell is it, and who is it filed for?
Swanson Magnesium 200 mg files 3 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 30 of 61 oxide labels that list magnesium stearate.
measured| Entry | Filed ingredient or declaration |
|---|---|
| 1 | Rice Flour |
| 2 | Gelatin |
| 3 | Magnesium Stearate |
| Shell | gelatin |
| Target group | Adult (18 - 50 Years) |
Source · NIH DSLD 202431 · label 2019-11-21; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What has research measured about oxide, and about side effects?
12 studies in the PubMed-checked registry measured outcomes involving oxide; 2 mention gastrointestinal or adverse outcomes. They measured the salt, not this label.
measured| Year | Study | PubMed |
|---|---|---|
| 2026 | Randomized, open-label study of the short-term pharmacokinetics of oral magnesium oxide in healthy volunteers. | 42091979 |
| 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?
Swanson has 6 FDA recall records matched by brand name in the enforcement data queried 2026-10-19. Swanson 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-0705-2013 | 2012-11-28 | This is to inform you of a product recall involving 2 lots of Swanson Organic 100% Certified Organic Fennel Seed (SWF092). Some jars of fennel seeds have been found to contain small, red beetle-type insects. | Terminated |
| F-0220-2014 | 2013-11-27 | Swanson Health Products is recalling two lots of Swanson Premium Full Spectrum Black Cumin Seed (Nigella sativa) Dietary Supplement Capsules. The product was found to be mislabel. Bottles of Black Cumin Seed from these two lots numbers (199399 & 201359) have been found to contain White Cumin Seed (Cuminum cyminum). | Terminated |
| F-1936-2014 | 2014-05-21 | The contract manufacturer has notified Swanson Health Products that Swanson Full Spectrum Cilantro (Coriander) (SW1112) is subject to a recall due to a potential risk of salmonella contamination. | Terminated |
| F-2438-2014 | 2014-09-24 | Swanson Certified Organic Carob Powder, item number SWF115 is being recalled due to a potential risk of Salmonella contamination from a raw ingredient used in this product. | Terminated |
| F-1985-2018 | 2018-10-03 | Himalayan Crystal Salt may contain metal wire pieces. | 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 202431 · label 2019-11-21; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Which labels are closest to this one, with the same salt and dose?
3 labels use the same resolved oxide within ±10% of this label's 200 mg per unit, compared side by side on price and capsule verdict.
computed| Label | Elemental per unit | Price | Verdict |
|---|---|---|---|
| Nutricost Magnesium Oxide 375 mg | 210 mg | $14.95 · 2026-11-02 | Fits size 0 |
| Douglas Laboratories MgO2 (Magnesium Caps) (DSLD 10307) | 215 mg | No price | Fits size 0 |
| Douglas Laboratories MgO2 (Magnesium Caps) (DSLD 10308) | 215 mg | No price | Fits size 0 |
Source · NIH DSLD 202431 · label 2019-11-21; 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 202431 (label 2019-11-21, 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 87614 01196 7). The CSV carries the values shown here.
measured| Field | As filed |
|---|---|
| NIH DSLD label | NIH DSLD 202431 |
| Label date | 2019-11-21 |
| Date entered into DSLD | 2019-11-21 |
| Barcode (UPC) as filed | 0 87614 01196 7 |
| Label version · Image difference, same product | NIH DSLD 174607 |
| Label version · Package size difference, same product | NIH DSLD 187460 |
| Label version · Package size difference, same product | NIH DSLD 174607 |
| Label version · Image difference, same product | NIH DSLD 159084 |
17 additional rows
| Field | As filed |
|---|---|
| Label version · Package size difference, same product | NIH DSLD 159084 |
| Distributed by | Swanson Health Products, Fargo, ND, USA |
| Claim category as filed | All Other |
| Claim category as filed | Structure/Function |
| General Statements: All Other Content | Essential for strong muscles and bones, cardiovascular health and more Helps maintain healthy blood pressure and glucose levels Science-Backed Quality Since 1969 |
| Suggested/Recommended/Usage/Directions | Suggested use: As a dietary supplement, take two capsules per day with food and water. |
| Precautions re: All Other | Warning: For adults only. |
| Precautions re: Pregnant or Nursing or Prescription Medications | Consult your physician before using this or any product if you are pregnant or nursing, taking medication, or have a medical condition. |
| Precautions re: Children | Keep out of reach of children. |
| Precautions re: All Other | Do not use if seal is broken. |
| Storage | Store in a cool, dry place. |
| 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. |
| General Statements: All Other Content | Muscle and bone health 200 mg per capsule |
| FDA Statement of Identity | Mineral Supplement |
| General: Product/Version Code | SW196 Rev 2 08 20 18 |
| Physical state | Capsule |
| Registry snapshot | 2026-08-10 |
Source · NIH DSLD 202431 · label 2019-11-21; 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.