A small test of 10 melatonin pills bought in the U.S. found that 4 of them had way more or way less melatonin than what was printed on the bottle — so you might not be getting what you think you're paying for.
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
This claim is descriptive and quantitative, based on direct laboratory measurement of product content. It reports an observed outcome from a specific sample (n=10), and the use of 'contained' is precise and factual. The 90–110% range is a standard pharmaceutical tolerance, making the claim scientifically grounded. No causal or probabilistic language is overreaching. The claim is appropriately limited to the sample tested and does not generalize beyond it.
More Accurate Statement
“Among a sample of 10 commercially available melatonin supplements in the U.S., 4 products contained melatonin concentrations that deviated by more than 10% from the labeled amount, falling outside the 90–110% acceptance range.”
Context Details
Domain
nutrition
Population
human
Subject
10 commercially available melatonin supplements in the U.S.
Action
contained
Target
melatonin levels outside the 90–110% range of the labeled amount
Intervention Details
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Evidence from Studies
Supporting (1)
1336 The Critical Importance of Quality and Purity Management in Melatonin Supplement Manufacturing