Label arithmetic · NIH DSLD 313575

NOW Magnesium Caps 400 mg

NOW Magnesium Caps 400 mg declares 400 mg of elemental magnesium per 1 Veg Capsule(s); the magnesium salt is not named in the filed record, no US retail price has been matched; NIH DSLD 313575, label dated 2024-10-24, calculation 2026-09-13.

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

Label facts and derived measurements

The numbers for this label

NOW Magnesium Caps 400 mg has 11 published fields below, traced to NIH DSLD 313575 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 identifier313575observed
Resolved saltSingle salt unresolved as of 2026-09-13computed
Source of the resolved saltSingle salt unresolved as of 2026-09-13observed
Elemental magnesium per serving (mg)400observed
Servings per container180observed
Elemental magnesium per container (mg)72000computed
Compound mass per discrete unitDiscrete unit mass not computable as of 2026-09-13computed
Capsule fill verdictMass budget unavailable as of 2026-09-13modelled
Required standard capsule sizeCapsule size not applicable or unresolved as of 2026-09-13modelled
Label date2024-10-24observed
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 Caps 400 mg retains 1 magnesium-related rows in NIH DSLD 313575, including 1 rows selected for the primary serving, from label 2024-10-24, 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

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 Caps 400 mg works out to 180 days per package at the label's own serving and filed frequency of 1 servings per day, according to label 2024-10-24, calculated 2026-09-13.

Arithmetic using the label's own serving, not intake advice
Net contents as filed180 Veg Capsule(s)
Discrete units in the package180
Serving size as filed1 Veg Capsule(s)
Units per serving1
Servings per package180
Daily servings in the label instructions1
Days per package at the label's own serving180 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.

Percent daily value · observed and computed

The label's percent daily value, recomputed

NOW Magnesium Caps 400 mg files 1 magnesium percent-daily-value entries in NIH DSLD 313575; 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 Caps 400 mg lists 4 other ingredients in NIH DSLD 313575, label dated 2024-10-24, examined 2026-09-13.

Other ingredients as filed
EntryIngredient
1Hypromellose
2Rice Flour
3Silicon Dioxide
4Stearic Acid

Capsule material: vegetarian. 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 Caps 400 mg has 7 target-group entries in NIH DSLD 313575, label dated 2024-10-24, examined 2026-09-13.

Manufacturer-filed target groups
EntryFiled group
1Vegan
2Vegetarian
3Adult (18 - 50 Years)
4Kosher
5Halal
6Gluten Free
7Dairy Free

Provenance · observed

Registry record, versions and scanned label

The registry holds 4 versions of this label for NOW Magnesium Caps 400 mg, according to the retained record examined 2026-09-13; the label date is 2024-10-24.

Source record for NOW Magnesium Caps 400 mg
NIH DSLD labelNIH DSLD 313575
Registry snapshot2026-08-10
Label date2024-10-24
Physical stateCapsule
Barcode as filed7 33739 01283 8
Versions held by the registry4; 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 Caps 400 mg has 2 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 313575 (barcode 7 33739 01283 8) as of 2026-09-13.
2A single salt with a defined elemental fraction is unresolved; compound mass cannot be computed 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.