Label arithmetic · NIH DSLD 335273

NOW Magnesium Citrate Softgels

NOW Magnesium Citrate Softgels declares 400 mg of elemental magnesium as citrate, which needs 825–1,180 mg of salt per unit — a size 000 capsule or larger; NIH DSLD 335273, label dated 2025-09-25, 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 335273, 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 335273
StepValueEvidence
Declared elemental magnesium400 mg per servingobserved · label 2025-09-25
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 unit825.08–1,179.94 mgcomputed

At powder density 0.6–0.8 g/mL, 825 mg of powder requires the largest standard size, 000 (holds about 1,100 mg).

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 335273 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 identifier335273observed
Resolved saltMagnesium citratecomputed
Source of the resolved saltfull-recordobserved
Elemental magnesium per serving (mg)400observed
Servings per container30observed
Elemental magnesium per container (mg)12000computed
Compound mass per discrete unit825.08–1,179.94 mgcomputed
Capsule fill verdictneeds-000modelled
Required standard capsule size000modelled
Label date2025-09-25observed
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 335273, including 1 rows selected for the primary serving, from label 2025-09-25, 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 2026-09-13

elemental, from

Selected 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 30 days per package at the label's own serving and filed frequency of 1 servings per day, according to label 2025-09-25, calculated 2026-09-13.

Arithmetic using the label's own serving, not intake advice
Net contents as filed90 Softgel(s)
Discrete units in the package90
Serving size as filed3 Softgel(s)
Units per serving3
Servings per package30
Daily servings in the label instructions1
Days per package at the label's own serving30 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 (12,000 mg elemental in NOW Magnesium Citrate Softgels) would correspond to $12.47, 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 package12,000 mg
Benchmark package equivalent$12.47 = 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 335273; 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 335273, label dated 2025-09-25, 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 335273, label dated 2025-09-25, 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 10 versions of this label for NOW Magnesium Citrate Softgels, according to the retained record examined 2026-09-13; the label date is 2025-09-25.

Source record for NOW Magnesium Citrate Softgels
NIH DSLD labelNIH DSLD 335273
Registry snapshot2026-08-10
Label date2025-09-25
Physical stateSoftgel Capsule
Barcode as filed7 33739 01297 5
Versions held by the registry10; 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 335273 (barcode 7 33739 01297 5) 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.

Labels with a matching filed formulation

2 labels from 2 brands share this record's lowercase excipient list, shell classification and serving structure with elemental mg per unit rounded to 5 mg, calculated 2026-09-13 from the filed NIH DSLD records.

Inspect the matching filed formulation and its label records. The match indicates similarity between filed records; it does not prove a common manufacturer.