Analytical surveys of unregulated peptide supply
What do published analytical surveys report about the identity, purity and content of peptides obtained from unregulated suppliers?
§1Abstract
§1.1Review question
What do published analytical surveys report about the identity, purity and content of peptides obtained from unregulated suppliers?
§1.2PICO frame
Table 1. The registered PICO frame. Any change made after protocol registration is recorded in the amendment log at §5 and is identified there as post hoc.
| Element | As registered |
|---|---|
| Population | Peptide products obtained from unregulated or direct-supply sources. |
| Intervention | Not applicable. |
| Comparator | The label claim and, where available, a reference standard. |
| Outcomes | Identity confirmation; chromatographic purity; peptide content against label; presence of undeclared substances. |
§1.3Method in brief
A review of analytical and quality evidence for a compound or class as supplied, rather than of clinical effect. The protocol was registered with the Institute's secretariat before the search was executed. The search was run on 30 June 2026 across 8 sources and is reproduced in full at §2. Screening, extraction and certainty assessment were performed independently by two members of the secretariat with disagreement resolved by a third.[1,2]
§1.4Conclusion
Low certainty evidence from a small number of analytical surveys indicates that identity is usually confirmed for the principal high-volume compounds and that content against label claim is more variable than purity, with a meaningful minority of samples falling materially below label. The certainty is low because the sampling frames are convenience samples selected for testing, are small, and are not comparable across surveys. The Institute reports the direction of the finding and declines to attach a market-wide proportion to it.
The conclusion rests on 24 contributing studies, listed with their extracted data at §3 and summarised outcome by outcome at §4.
§1.5Limitations
§1.6Consultation
This review was released for public comment before ratification. Draft analytical review: surveys of unregulated peptide supply received 14 submissions. Amendments arising are recorded in the amendment log and are traceable to a numbered submission.
References cited on this page
References are numbered in order of first citation in this document. Each superscript in the text links to its entry below.
- Sodhi M, Rezaeianzadeh R, Kezouh A, Etminan M. Risk of gastrointestinal adverse events associated with glucagon-like peptide-1 receptor agonists for weight loss. JAMA 2023;330(18):1795–1797. doi:10.1001/jama.2023.19574 · PMID 37796527
- Carvalho M, Dinis-Oliveira RJ. Analytical and forensic aspects of counterfeit peptide hormones. Drug Testing and Analysis 2023;15(1):5–19. doi:10.1002/dta.3379
Identifiers are reproduced only where the Institute holds them. Where a digital object identifier or PubMed identifier is not shown, the Institute has recorded the journal and year and has not constructed an identifier.