Label arithmetic · NIH DSLD 313607

NOW Magnesium Citrate Softgels

NOW Magnesium Citrate Softgels declares 400 mg of elemental magnesium per serving as citrate, which would require 2,475–3,540 mg of the salt in each unit — more than the 1,100 mg a size 000 capsule holds; NIH DSLD 313607, label dated 2024-05-23, calculation 2026-09-13.

FDA recall records for NOW: 1 · queried 2026-09-13; brand-string matches across products.

Mass budget · computed; capsule comparison · modelled

What the declared salt would weigh

NOW Magnesium Citrate Softgels declares 400 mg of elemental magnesium per serving in NIH DSLD 313607, requiring 2,475.25–3,539.82 mg of magnesium citrate under the salt model calculated 2026-09-13.

Elemental-to-compound conversion for NIH DSLD 313607
StepValueEvidence
Declared elemental magnesium400 mg per servingobserved · label 2024-05-23
Resolved saltMagnesium citrate · full-recordcomputed · name resolved from filed text
Reference formulaMg₃(C₆H₅O₇)₂; 451.11 g/molcomputed · chemical reference
Elemental fraction11.3–16.16% by masscomputed
Why the fraction is a rangetrimagnesium dicitrate 16.2%; dibasic and hydrated forms as low as 11.3%modelled · hydrate not specified
Compound mass per serving2,475.25–3,539.82 mg = 400 mg ÷ elemental fractioncomputed
Compound mass per discrete unit2,475.25–3,539.82 mgcomputed

At powder density 0.6–0.8 g/mL, 2,475 mg of powder exceeds every standard capsule size — the largest, 000, holds about 1,100 mg.

If the declared salt were the sole source of magnesium here, each capsule would need 2,475 mg of powder, which no standard capsule holds. So the label does not establish citrate as the only source. A blend with a denser salt or a non-standard capsule could reconcile it. This is a statement about the label's arithmetic, not about what is in the bottle.

The verdict uses the most favourable reading for the product — the smallest compound mass the label allows. It excludes the shell and other ingredients; their unreported masses are not added as guesses.

Size 0 holds about 545 mg, size 00 about 730 mg, and size 000 about 1,100 mg at powder density 0.6–0.8 g/mL. These are model inputs, not measurements of this product's capsule. Read the mass-budget method.

Label facts and derived measurements

The numbers for this label

NOW Magnesium Citrate Softgels has 11 published fields below, traced to NIH DSLD 313607 and the 2026-08-10 registry snapshot, with calculations dated 2026-09-13.

Values published in this page's Product metadata
FieldValueEvidence tier
NIH DSLD identifier313607observed
Resolved saltMagnesium citratecomputed
Source of the resolved saltfull-recordobserved
Elemental magnesium per serving (mg)400observed
Servings per container60observed
Elemental magnesium per container (mg)24000computed
Compound mass per discrete unit2,475.25–3,539.82 mgcomputed
Capsule fill verdictexceeds-allmodelled
Required standard capsule sizeNo standard size fits as of 2026-09-13modelled
Label date2024-05-23observed
Retail match confidenceunmatchedcomputed

Observed means a value transcribed from a label or price observation. Computed means arithmetic or normalization of those inputs. Modelled means the result depends on a stated physical assumption, including capsule capacity. Evidence tiers and their limits.

Source transcription · observed

Magnesium lines as filed

NOW Magnesium Citrate Softgels retains 1 magnesium-related rows in NIH DSLD 313607, including 1 rows selected for the primary serving, from label 2024-05-23, examined 2026-09-13.

Filed amounts, salt names and serving order
Filed amountServing orderFiled salt / notesCalculation role
400 mg1Salt not identified in this row as of 2026-09-13Selected primary serving

The elemental amount comes from the selected magnesium line. A salt named under another nutrient does not make that nutrient's quantity an elemental magnesium value. Distinct unresolved primary amounts remain ambiguous; they are not added together.

Package arithmetic · observed inputs, computed totals

What the package works out to

NOW Magnesium Citrate Softgels works out to 20 days per package at the label's own serving and filed frequency of 3 servings per day, according to label 2024-05-23, calculated 2026-09-13.

Arithmetic using the label's own serving, not intake advice
Net contents as filed180 Softgel(s)
Discrete units in the package180
Serving size as filed1 Softgel(s)
Units per serving1
Servings per package60
Daily servings in the label instructions3
Days per package at the label's own serving20 days

Days = filed servings per container ÷ filed servings per day. If the label gives a frequency range, the largest frequency gives the shortest duration. Cost per serving = observed item price ÷ filed servings; cost per label-day multiplies this by the filed frequency. This follows the label's own instructions; it is package arithmetic, not intake advice.

Benchmark · 19 observed prices in citrate

A same-salt reference for this package

At the median cost per 100 mg observed across 19 citrate labels ($0.1039), a package of this size (24,000 mg elemental in NOW Magnesium Citrate Softgels) would correspond to $24.94, using observations from 2026-08-10 to 2026-09-11, calculated 2026-09-13. This is a benchmark, not a retailer quote.

Same-salt benchmark working
Salt and number of observationsMagnesium citrate · n = 19
Median observed cost per 100 mg$0.1039
Filed elemental magnesium per package24,000 mg
Benchmark package equivalent$24.94 = median EC100 × package elemental mg ÷ 100
Evidence tierbenchmark · calculated 2026-09-13

The median is the middle sorted observation, or the average of the two middle observations for an even group. Each label contributes one observation. This value is neither an offer nor an estimate of a specific retailer's current price.

Percent daily value · observed and computed

The label's percent daily value, recomputed

NOW Magnesium Citrate Softgels files 1 magnesium percent-daily-value entries in NIH DSLD 313607; the check below applies the group-specific references in 21 CFR 101.9 to its 400 mg primary serving, calculated 2026-09-13.

Declared values and current-reference arithmetic
Group as filedDeclaredReferenceRecomputedDifference
Adults and children 4 or more years of age95%420 mg95%0 percentage points

Percent daily value = declared elemental mg ÷ the group's reference mg × 100, rounded to an integer. The adult and age-four-plus reference is 420 mg. Historical labels can use earlier references; a difference does not establish a filing error. Full-record entries may cover multiple serving sizes, so this table identifies the primary-serving basis explicitly. Group references and interpretation.

Composition · observed

Other ingredients in the filed record

NOW Magnesium Citrate Softgels lists 6 other ingredients in NIH DSLD 313607, label dated 2024-05-23, examined 2026-09-13.

Other ingredients as filed
EntryIngredient
1Rice Bran Oil
2Bovine Gelatin
3Glycerin
4Water
5Beeswax
6Sunflower Lecithin

Capsule material: gelatin. The material classification follows the filed ingredient names; it is not a test of the shell.

Label declarations · observed

Target groups as filed

NOW Magnesium Citrate Softgels has 5 target-group entries in NIH DSLD 313607, label dated 2024-05-23, examined 2026-09-13.

Manufacturer-filed target groups
EntryFiled group
1Adult (18 - 50 Years)
2Kosher
3Halal
4Gluten Free
5Dairy Free

Provenance · observed

Registry record, versions and scanned label

The registry holds 9 versions of this label for NOW Magnesium Citrate Softgels, according to the retained record examined 2026-09-13; the label date is 2024-05-23.

Source record for NOW Magnesium Citrate Softgels
NIH DSLD labelNIH DSLD 313607
Registry snapshot2026-08-10
Label date2024-05-23
Physical stateSoftgel Capsule
Barcode as filed7 33739 01298 2
Versions held by the registry9; version details are not available in this enrichment record as of 2026-09-13
Source scanScanned label (NIH DSLD)
Calculation date2026-09-13

The barcode is retained as an identifier, not as proof of a retail match. A registry version count records the number held; it does not reveal what changed. The label date, registry snapshot and price-observation date describe different events.

Gaps in this record

What is not available for this label

NOW Magnesium Citrate Softgels has 1 unresolved data gaps in the retained NIH DSLD and price records as of 2026-09-13.

Dated missing-data statements
EntryKnown gap
1No confirmed US retail price matched to NIH DSLD 313607 (barcode 7 33739 01298 2) as of 2026-09-13.

An unmatched retail price describes our matching coverage. It does not establish that a product is unavailable. The elemental cost calculator can apply the same EC100 formula to a price you supply.