Label arithmetic · NIH DSLD 261002
Wonder Labs Magnesium Oxide 400: 241 mg of magnesium per tablet, 2 tablets a day, $5.16 a month
241 mg of magnesium per tablet; the label's 2 tablets a day cost $5.16 a month (Amazon, Nov 2). Inside: salt weight, %DV check, price rank.
Wonder Labs Magnesium Oxide 400 was observed at $21.49 on 2026-11-02 for 125 servings of 483 mg elemental magnesium as oxide: $0.0356 per 100 mg, rank 4 of 5 ranked oxide offers (1 = lowest price per 100 mg), percentile 80 (lower = lower price) (median $0.0293, ranked prices observed 2026-10-26 to 2026-11-02). NIH DSLD 261002, label dated 2021-11-19.
computed from the filed label
Chart data
| Displayed chart text |
|---|
| gluconate |
| 8,235 |
| orotate |
| 6,638 |
| L-threonate |
| 5,850 |
| taurate |
| 5,410 |
| lactate |
| 4,018 |
| glycerophosphate |
| 3,861 |
| glycinate |
| 3,423 |
| malate |
| 3,106 |
| aspartate |
| 3,086 |
| citrate |
| 2,986 |
| sulfate |
| 2,390 |
| chloride |
| 1,890 |
| carbonate |
| 1,674 |
| hydroxide |
| 1,158 |
| oxide |
| 800 |
Data release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · latest price observation 2026-11-02 · chemistry 2026-10-17
Mass: 400 mg per tablet · Price: $0.0356 per 100 mg · % DV: 121% vs 115%
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 oxide is pressed into one tablet?
Wonder Labs Magnesium Oxide 400 carries 800 mg of magnesium oxide per serving for 483 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 | 483 mg |
| Units per serving | 2 |
| Magnesium oxide per serving | 800 mg |
| Magnesium oxide per tablet | 400 mg |
| Capsule capacity 0 · 00 · 000 | 545 · 730 · 1,100 mg |
| Verdict | Capsule sizes do not apply |
Source · NIH DSLD 261002 · label 2021-11-19; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
How much elemental magnesium is actually in this label's filed magnesium lines?
Wonder Labs Magnesium Oxide 400 files 1 magnesium line in NIH DSLD 261002; the selected primary line declares 483 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 |
|---|---|---|
| 483 mg | elemental magnesium | Primary serving |
Source · NIH DSLD 261002 · label 2021-11-19; 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 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 oxide | 60.3% | full NIH DSLD record text |
Source · NIH DSLD 261002 · label 2021-11-19; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Is this a good price for the elemental magnesium I'm actually getting?
Wonder Labs Magnesium Oxide 400 costs $0.0356 per 100 mg of elemental magnesium at the price observed 2026-11-02, rank 4 of 5 ranked oxide offers (1 = lowest price per 100 mg), percentile 80 (lower = lower price), against a same-salt median of $0.0293; prices observed 2026-10-26 to 2026-11-02. First observed 2026-10-12 at $21.49, latest 2026-11-02 at $21.49, 3 observations.
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, Wonder Labs Magnesium Oxide 400 lasts 125 days: 125 servings against 1 serving a day in the filed directions. $5.16 a month at the label's suggested use (2 tablets a day) and $4.49 at the 420 mg Daily Value reference (21 CFR 101.9); arithmetic on the label, not intake advice.
computed| Measure | Value |
|---|---|
| Net contents as filed | 250 Tablet(s) |
| Serving size as filed | 2 Tablet(s) |
| Servings per container | 125 |
| Servings per day in the directions | 1 |
| Days per bottle | 125 days |
| Cost a month at the label suggested use | $5.16 a month at the label's suggested use (2 tablets a day) |
| $ per 30 days at 420 mg Daily Value | $4.49 |
Source · NIH DSLD 261002 · label 2021-11-19; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does "121% Daily Value" mean here, and does it recompute?
The label declares 121% Daily Value; 483 mg against the 420 mg reference in 21 CFR 101.9 recomputes to 115%, a difference of 6 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 |
| 115 · 121 |
| Declared vs |
| recomputed % DV |
| Group as filed | Declared | Reference | Recomputed |
|---|---|---|---|
| Adults and children 4 or more years of age | 121% | 420 mg | 115% |
Source · NIH DSLD 261002; 21 CFR 101.9 · label 2021-11-19 · release 2026-08-10-f441aa9f · CSV · method
Why does this label contain magnesium stearate, what shell is it, and who is it filed for?
Wonder Labs Magnesium Oxide 400 files 4 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 30 of 61 oxide labels that list magnesium stearate.
measured| Entry | Filed ingredient or declaration |
|---|---|
| 1 | Vegetable Cellulose |
| 2 | Vegetable Stearic Acid |
| 3 | Vegetable Magnesium Stearate |
| 4 | Silica |
| Shell | vegetarian |
| Target group | Adult (18 - 50 Years) |
| Target group | Gluten Free |
| Target group | Sugar Free |
Source · NIH DSLD 261002 · label 2021-11-19; 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?
Wonder Labs has 0 FDA recall records matched by brand name in the enforcement data queried 2026-10-19. Wonder Labs has no FDA CAERS adverse event report on record at brand level as of 2026-10-19 (143 of 273 brands in this registry have at least one CAERS report).
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?
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 261002 · label 2021-11-19; 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 oxide within ±10% of this label's 241 mg per unit, compared side by side on price and capsule verdict.
computed| Label | Elemental per unit | Price | Verdict |
|---|---|---|---|
| Genesis Products Magnesium-Oxide | 241 mg | No price | Capsule sizes do not apply |
| Rising MAGnesium-Oxide | 241 mg | No price | Capsule sizes do not apply |
| Wonder Labs Magnesium Oxide 400 (DSLD 262919) | 241 mg | $21.49 · 2026-11-02 | Capsule sizes do not apply |
| Wonder Labs Magnesium Oxide 400 (DSLD 316129) | 241 mg | $21.49 · 2026-11-02 | Capsule sizes do not apply |
| Graxcell Pharmaceutical, LLC. Magnesium Oxide 400 mg | 242 mg | No price | Capsule sizes do not apply |
| Foods Plus Magnesium 400 | 240 mg | No price | Capsule sizes do not apply |
Source · NIH DSLD 261002 · label 2021-11-19; 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 261002 (label 2021-11-19, snapshot 2026-08-10), a price observed 2026-11-02 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 261002 |
| Scanned label (PDF) | Label 261002 scan |
| Label date | 2021-11-19 |
| Date entered into DSLD | 2021-11-19 |
| Barcode (UPC) as filed | 0 99528 68025 2 |
| Label version · Package size difference, same product | NIH DSLD 162685 |
| Label version · Package size difference, same product | NIH DSLD 260661 |
| Label version · Package size difference, same product | NIH DSLD 256194 |
33 additional rows
| Field | As filed |
|---|---|
| Label version · Package size difference, same product | NIH DSLD 260941 |
| Label version · Package size difference, same product | NIH DSLD 316128 |
| Label version · Package size difference, same product | NIH DSLD 262919 |
| Label version · Package size difference, same product | NIH DSLD 263150 |
| Label version · Package size difference, same product | NIH DSLD 262974 |
| Label version · Image difference, same product | NIH DSLD 316129 |
| Label version · Image difference, same product | NIH DSLD 256194 |
| Label version · Image difference, same product | NIH DSLD 262919 |
| Label version · Image difference, same product | NIH DSLD 263150 |
| Label version · Image difference, same product | NIH DSLD 262974 |
| Label version · Package size difference, same product | NIH DSLD 316129 |
| Manufactured Exclusively for | Wonder Laboratories, White House, TN |
| Claim category as filed | All Other |
| Claim category as filed | Structure/Function |
| Suggested/Recommended/Usage/Directions | Directions: For adults, take two (2) tablets daily with food or as directed by a physician. |
| Precautions re: All Other | Tamper evident: Do not use this product if imprinted foil seal under cap is broken or missing. |
| Precautions re: Children | Keep out of reach of children. |
| Storage | Keep tightly closed. Store at room temperature: 59 degrees - 86 degrees F (15 degrees to 30 degrees C). |
| Formulation re: Other | Conforms to USP <2091> for weight. Meets USP <2040> disintegration for maximum bioavailability. |
| Precautions re: Pregnant or Nursing or Prescription Medications | Caution: If you are pregnant, nursing, have kidney disease or are taking prescription medications, consult your physician before taking this product. |
| Formulation re: Does NOT Contain | Non-GMO |
| Seals/Symbols | FDA Registered Facility GMP Good Manufacturing Practice USA Made |
| 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. |
| General Statements: All Other Content | Freedom if life - Live with wonder |
| Formulation re: Other | Pharmaceutical grade |
| Formulation re: Other | Promotes bone mineralization and cardiovascular health |
| FDA Statement of Identity | Dietary Supplement |
| Formulation re: Other | Compare to active ingredient of MAG-OX 400 |
| Formulation re: Does NOT Contain | Sugar free/Gluten free |
| Brand IP Statement(s) re: (c), (TM), (SM) | This product is not manufactured or distributed by Hi-Tech Pharmacal Co., owners of the reg. trademark MAG-OX 400. Home of the world famous Valerin |
| General Statements: All Other Content | Reorder #6802 |
| Physical state | Tablet or Pill |
| Registry snapshot | 2026-08-10 |
Source · NIH DSLD 261002 · label 2021-11-19; 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.