Measurement / residue studyindependent cross-checkabstract checked I-SUP-120 standard review
Mislabelled supplements linked to liver injury
The Contents of Herbal and Dietary Supplements Implicated in Liver Injury in the United States Are Frequently Mislabeled.
Overview
Navarro V et al.. Hepatol Commun 2019 · PMID 31168513 · DOI 10.1002/hep4.1346
Half of the supplements taken by US patients with liver injury did not contain what their labels said.
Does the study support the specific claim? Partly · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
To check supplement contents against labels.
- How was the study done?
Chemical analysis.
- How many people, animals or samples were studied?
272 products.
- What was actually found?
51% mislabelled.
- How large was the observed effect?
51%.
- What do the results mean in everyday life?
Bodybuilding, sexual-performance and slimming products are risky because contents may be hidden.
- What are the study's limitations?
Selected products.
- What does it say about Elawady's specific claim?
Supports caution, not the universal claim.
- Do the results apply to Germany and Europe?
US market.
- What can explicitly not be concluded from this study?
Cannot estimate risk for vitamins in general.
Scientific in-depth review
1. Full reference
- Authors
- Navarro V et al.
- Journal
- Hepatol Commun
- Year
- 2019
- Identifier
- PMID 31168513 DOI 10.1002/hep4.1346 · PMC6545864
- Verification
- verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
No COI statement in PubMed record; funding listed: NIDDK NIH HHS
2. Research question
Do product labels match the chemical contents of HDS implicated in liver injury?
3. Study design and population
- Study design
- Measurement / residue study – Laboratory analysis of supplement products implicated in liver injury (DILIN)
- Population
Products collected from DILIN patients
- Country
USA
- Period
Not stated in abstract
- Sample size
272 products
- Inclusion and exclusion criteria
HDS products from enrolled patients
4. Methods and endpoints
- Exposure / intervention
Product contents (HPLC-MS)
- Comparator
Label claims
- Endpoints
Mislabelling; known hepatotoxins
- Statistical methods
Descriptive
5. Actual results
- Results
51% of products were mislabelled (contents did not match label); appearance-enhancement, sexual-performance and weight-loss products most often mislabelled.
- Absolute risks
Not applicable
- Authors' conclusion
The high mislabelling rate underscores the need for stricter regulation of supplements.
6. Strengths
- Chemical verification of products
7. Weaknesses
- Selected products (from injury cases)
- Whether mislabelling caused injury not established
8. Risk of bias
- Orienting tool
- none applicable
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- not assessable
- Rationale
Descriptive analytical study.
9. Assessment of the statistical interpretation
Not applicable.
10. Relevance to the specific claim
Supports concern about product quality and hidden ingredients, which is a real basis for caution with some supplements.
11. Independent contrary findings
Products are a selected sample from injury cases.
12. Transferability to Germany and Europe
Market regulation differs; quality problems also reported in other markets (not reviewed).
13. Overall methodological judgement
Supports caution about unregulated multi-ingredient products, not a universal liver-toxicity claim.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | not assessable |
| Precision of results | not applicable |
| Directness | indirect |
| Reproducibility | unknown |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Mislabelling rates in Egyptian products.