Label arithmetic · NIH DSLD 232777
Douglas Laboratories Magnesium Citrate: 150 mg of magnesium per capsule, 1 capsule a day, $6.33 a month
150 mg of magnesium per capsule; the label's 1 capsule a day cost $6.33 a month (Amazon, Nov 2). Inside: salt weight, capsule size, price rank.
Douglas Laboratories Magnesium Citrate declares 150 mg of elemental magnesium per serving as citrate, which needs 928–1,327 mg of magnesium citrate 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. Observed at $0.1407 per 100 mg, rank 8 of 12 ranked citrate offers (1 = lowest price per 100 mg), percentile 67 (lower = lower price). NIH DSLD 232777, label dated 2020-08-23.
computed from the filed label
Chart data
| Displayed chart text |
|---|
| 545 mg |
| 730 mg |
| 1,100 mg |
| 928–1,327 mg of citrate per capsule |
Data release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · latest price observation 2026-11-02 · chemistry 2026-10-17
Mass: 928–1,327 mg per capsule · Price: $0.1407 per 100 mg · % DV: 36% vs 36%
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 150 mg of citrate actually fit in one capsule, or do I need more than one?
Estimated salt mass versus assumed capsule capacity: Douglas Laboratories Magnesium Citrate implies 928–1,327 mg of magnesium citrate in each capsule to deliver 150 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 | 150 mg |
| Units per serving | 1 |
| Magnesium citrate per serving | 928–1,327 mg |
| Magnesium citrate per capsule | 928–1,327 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 (trimagnesium dicitrate 16.2%; dibasic and hydrated forms as low as 11.3%), so the compound mass is a range.
Source · NIH DSLD 232777 · label 2020-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
How much elemental magnesium is actually in this label's filed magnesium lines?
Douglas Laboratories Magnesium Citrate files 1 magnesium line in NIH DSLD 232777; the selected primary line declares 150 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 |
|---|---|---|
| 150 mg | citrate · Magnesium (Form: as Magnesium Citrate) | Primary serving |
Source · NIH DSLD 232777 · label 2020-08-23; 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 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 citrate | 11.3–16.2% | filed magnesium line |
Source · NIH DSLD 232777 · label 2020-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Is this a good price for the elemental magnesium I'm actually getting?
Douglas Laboratories Magnesium Citrate costs $0.1407 per 100 mg of elemental magnesium at the price observed 2026-11-02, rank 8 of 12 ranked citrate offers (1 = lowest price per 100 mg), percentile 67 (lower = lower price), against a same-salt median of $0.1159; prices observed 2026-10-26 to 2026-11-02. First observed 2026-10-26 at $19.00, latest 2026-11-02 at $19.00, 2 observations.
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 |
| 8 | Douglas Laboratories Magnesium Citrate (this label) | $0.1407 | 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, Douglas Laboratories Magnesium Citrate lasts 90 days: 90 servings against 1 serving a day in the filed directions. $6.33 a month at the label's suggested use (1 capsule a day) and $17.73 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 | 90 Vegetarian Capsule(s) |
| Serving size as filed | 1 Vegetarian Capsule(s) |
| Servings per container | 90 |
| Servings per day in the directions | 1 |
| Days per bottle | 90 days |
| Cost a month at the label suggested use | $6.33 a month at the label's suggested use (1 capsule a day) |
| $ per 30 days at 420 mg Daily Value | $17.73 |
Source · NIH DSLD 232777 · label 2020-08-23; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does "36% Daily Value" mean here, and does it recompute?
The label declares 36% Daily Value; 150 mg against the 420 mg reference in 21 CFR 101.9 recomputes to 36%, the same within one point.
computed| Group as filed | Declared | Reference | Recomputed |
|---|---|---|---|
| Adults and children 4 or more years of age | 36% | 420 mg | 36% |
Source · NIH DSLD 232777; 21 CFR 101.9 · label 2020-08-23 · 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?
Douglas Laboratories Magnesium Citrate files 2 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 | Hydroxypropyl Methylcellulose |
| 2 | Ascorbyl Palmitate |
| Shell | vegetarian |
| Target group | Adult (18 - 50 Years) |
| Target group | Gluten Free |
Source · NIH DSLD 232777 · label 2020-08-23; 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?
Douglas Laboratories has 1 FDA recall record matched by brand name in the enforcement data queried 2026-10-19. Douglas Laboratories 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-1202-2015 | 2015-02-18 | Bottles contained a vegetarian digestive enzyme dietary supplement instead of melatonin. | 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 232777 · label 2020-08-23; 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 citrate within ±10% of this label's 150 mg per unit, compared side by side on price and capsule verdict.
computed| Label | Elemental per unit | Price | Verdict |
|---|---|---|---|
| Douglas Laboratories Magnesium Citrate | 150 mg | No price | Needs size 000 |
| Natural Factors Magnesium Citrate 150 mg Key Lime | 150 mg | No price | Capsule sizes do not apply |
| Natural Factors Magnesium Citrate 150 mg (DSLD 220684) | 150 mg | No price | Needs size 000 |
| Natural Factors Magnesium Citrate 150 mg (DSLD 220688) | 150 mg | No price | Needs size 000 |
| PureFormulas Magnesium Citrate | 150 mg | No price | Needs size 000 |
| Adaptogen Research Magnesium Citrate | 150 mg | No price | Needs size 000 |
Source · NIH DSLD 232777 · label 2020-08-23; 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 232777 (label 2020-08-23, 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 232777 |
| Label date | 2020-08-23 |
| Date entered into DSLD | 2020-08-23 |
| Barcode (UPC) as filed | 3 10539 97752 1 |
| Label version · Image difference, same product | NIH DSLD 5297 |
| Label version · Image difference, same product | NIH DSLD 10266 |
| Label version · Image difference, same product | NIH DSLD 30818 |
| Label version · Image difference, same product | NIH DSLD 56862 |
15 additional rows
| Field | As filed |
|---|---|
| Label version · Image difference, same product | NIH DSLD 70971 |
| Manufactured for | Douglas Laboratories, Pittsburgh, PA |
| Claim category as filed | All Other |
| Claim category as filed | Structure/Function |
| Suggested/Recommended/Usage/Directions | Suggested Usage: As a dietary supplement, adults take 1 capsule daily or as directed by your health professional. |
| Precautions re: Pregnant or Nursing or Prescription Medications | Warning: If you are pregnant or nursing, or if you are taking prescription medications, consult your health professional before using this supplement. |
| Precautions re: Children | Keep out of the reach of children. |
| Storage | Store in a cool, dry place. |
| Precautions re: All Other | Use only if safety seal is intact. |
| Formulation re: Does NOT Contain | Gluten-free, Non-GMO |
| 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 | Scan to learn about our manufacturing excellence Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity. |
| FDA Statement of Identity | Dietary Supplement |
| Physical state | Capsule |
| Registry snapshot | 2026-08-10 |
Source · NIH DSLD 232777 · label 2020-08-23; 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.