Label arithmetic · NIH DSLD 72119

NOW Magnesium Oxide Pure Powder

NOW Magnesium Oxide Pure Powder declares 290 mg of elemental magnesium per 0.25 tsp (approx. 500 mg); no US retail price has been matched; NIH DSLD 72119, label dated 2017-04-25, 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 Oxide Pure Powder declares 290 mg of elemental magnesium per serving in NIH DSLD 72119, requiring 480.77 mg of magnesium oxide under the salt model calculated 2026-09-13.

Elemental-to-compound conversion for NIH DSLD 72119
StepValueEvidence
Declared elemental magnesium290 mg per servingobserved · label 2017-04-25
Resolved saltMagnesium oxide · label-rowcomputed · name resolved from filed text
Reference formulaMgO; 40.3 g/molcomputed · chemical reference
Elemental fraction60.32% by masscomputed
Compound mass per serving480.77 mg = 290 mg ÷ elemental fractioncomputed

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 Oxide Pure Powder has 11 published fields below, traced to NIH DSLD 72119 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 identifier72119observed
Resolved saltMagnesium oxidecomputed
Source of the resolved saltlabel-rowobserved
Elemental magnesium per serving (mg)290observed
Servings per container454observed
Elemental magnesium per container (mg)131660computed
Compound mass per discrete unitDiscrete unit mass not computable as of 2026-09-13computed
Capsule fill verdictnot-applicablemodelled
Required standard capsule sizeCapsule size not applicable or unresolved as of 2026-09-13modelled
Label date2017-04-25observed
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 Oxide Pure Powder retains 1 magnesium-related rows in NIH DSLD 72119, including 1 rows selected for the primary serving, from label 2017-04-25, examined 2026-09-13.

Filed amounts, salt names and serving order
Filed amountServing orderFiled salt / notesCalculation role
290 mg1oxide

Magnesium (Form: from Magnesium Oxide)

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 Oxide Pure Powder works out to 454 days per package at the label's own serving and filed frequency of 1 servings per day, according to label 2017-04-25, calculated 2026-09-13.

Arithmetic using the label's own serving, not intake advice
Net contents as filed8 oz.; 227 Gram(s)
Serving size as filed0.25 tsp (approx. 500 mg)
Servings per package454
Daily servings in the label instructions1
Days per package at the label's own serving454 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 · 14 observed prices in oxide

A same-salt reference for this package

At the median cost per 100 mg observed across 14 oxide labels ($0.0571), a package of this size (131,660 mg elemental in NOW Magnesium Oxide Pure Powder) would correspond to $75.11, 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 oxide · n = 14
Median observed cost per 100 mg$0.0571
Filed elemental magnesium per package131,660 mg
Benchmark package equivalent$75.11 = 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 Oxide Pure Powder files 1 magnesium percent-daily-value entries in NIH DSLD 72119; the check below applies the group-specific references in 21 CFR 101.9 to its 290 mg primary serving, calculated 2026-09-13.

Declared values and current-reference arithmetic
Group as filedDeclaredReferenceRecomputedDifference
Adults and children 4 or more years of age69%420 mg69%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 Oxide Pure Powder lists 1 other ingredients in NIH DSLD 72119, label dated 2017-04-25, examined 2026-09-13.

Other ingredients as filed
EntryIngredient
1None

Capsule material: Not identified from the other-ingredient text as of 2026-09-13. 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 Oxide Pure Powder has 5 target-group entries in NIH DSLD 72119, label dated 2017-04-25, examined 2026-09-13.

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

Provenance · observed

Registry record, versions and scanned label

The registry holds 4 versions of this label for NOW Magnesium Oxide Pure Powder, according to the retained record examined 2026-09-13; the label date is 2017-04-25.

Source record for NOW Magnesium Oxide Pure Powder
NIH DSLD labelNIH DSLD 72119
Registry snapshot2026-08-10
Label date2017-04-25
Physical statePowder
Barcode as filed7 33739 01310 1
Versions held by the registry4; version details are not available in this enrichment record as of 2026-09-13
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 Oxide Pure Powder 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 72119 (barcode 7 33739 01310 1) 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.