How to read a Supplement Facts panel
A Supplement Facts panel states what the maker printed, per serving. It is not a dose, not a target and not a recommendation.
Serving Size
The serving size is the basis the maker chose to print the panel against: one tablet, or three. Every figure below it is per serving. A product with 500 mg per tablet and two tablets per serving prints 1000 mg per serving — twice the intake of one that prints 1000 mg per tablet. Identical figures do not mean identical amounts.
Amount Per Serving
This is the printed amount of one nutrient in one serving. A blank or a dash means the maker did not list it: either the product contains none, or it contains some that was not measured or printed — the label cannot say which.
A total therefore leaves an unlisted nutrient out rather than counting it as zero; counting it as zero would turn “unknown” into a number that looks certain. On product pages, such entries are marked “not listed on label”.
% Daily Value
The percentage is measured against the US Daily Value, a fixed labelling reference for adults. It does not vary with age, sex or diet: the same figure prints the same percentage for someone who needs more iron and for someone who does not.
Nor is it an upper limit. 250% is not an excess and 40% is not a shortfall — the percentage says nothing about enough or too much. Nutrients without a Daily Value are marked with a dagger (†) and no percentage. To judge how close an intake runs to the safety boundary, compare it with the tolerable upper intake level (UL), a different figure from a different body.
Servings Per Container
Servings per container states how long the bottle lasts: 120 tablets at three tablets a serving is 40 servings, not 120. It says nothing about intake. Before anything is totalled, each label needs its own servings a day.
The date on the bottle
US labels write month/day/year; most other regions write day/month/year. 03/09/2026 is 9 March under the first and 3 September under the second — the same eight characters, six months apart. Where a month name is printed, read that.
A lot or batch code is not a date, even when its digits look like one. “Best by” is the maker’s quality date, not a safety deadline.
IU, mcg and mg
Milligrams, micrograms and grams are masses, convertible by definition: 1 mg is 1000 mcg, and no source is needed for that.
IU is a unit of activity. How many micrograms one IU stands for depends on the chemical form: vitamin D2 and D3, retinol and beta-carotene, natural and synthetic vitamin E all differ. Where the label does not name the form, no defensible conversion exists, and Dosescope keeps the amount in its printed unit rather than guessing.