Label claim
A label claim is the amount of an ingredient that a product's label says each serving contains. Laboratory tests compare the measured amount with it to judge whether a product matches its label.
What it means in practice
Under the US labeling rule, compliance is judged on a composite sample of 12 consumer packages or 10 percent of the packages in the same inspection lot, whichever is smaller [2]. The rule also says that "reasonable excesses over labeled amounts are acceptable within current good manufacturing practice" [2]. Manufacturers must verify that finished batches meet specifications for identity, purity, strength and composition, either for every batch or for a subset chosen by a sound statistical sampling plan [3].
Researchers also test products against their label claims. In one 2017 laboratory study of commercial melatonin natural health products and supplements, by a team at the University of Guelph in Canada, measured melatonin ranged from -83% to +478% of the labeled content [1]. Content differed by as much as 465% between lots of the same product, and more than 71% of products were not within 10% of their label claim [1]. Serotonin, a related compound, was found in eight of the supplements [1].
Why it matters when reading nootropics research
Doses used in studies describe what participants were given. A product's label claim is the company's statement of what each serving holds. Comparing the two assumes the label is right, and the melatonin results show it sometimes is not [1].
A proprietary blend has no label claim for each ingredient, only a total weight for the blend [2]. "Label claim" in this sense is about amount; it is different from a structure/function claim, which is a statement about what an ingredient is meant to do.
References
- Erland LA, Saxena PK. Melatonin Natural Health Products and Supplements: Presence of Serotonin and Significant Variability of Melatonin Content. J Clin Sleep Med. 2017.
- Electronic Code of Federal Regulations (eCFR). 21 CFR 101.36 Nutrition labeling of dietary supplements. eCFR title 21 up to date as of 2026-11-09.
- Electronic Code of Federal Regulations (eCFR). 21 CFR 111.75 What must you do to determine whether specifications are met?. eCFR title 21 up to date as of 2026-11-09.