Vendor Intelligence Report: YuYi peptide

Published 2 Jul 2026. 18-page investigative report on who is behind YuYi peptide: corporate records, ownership, affiliate networks, and the vendor's lab-testing record. The first 3 pages are free to read on this page.

Researched and published by Finnrick Analytics. Reports draw on corporate records, affiliate-network analysis, and Finnrick's own laboratory testing record; vendors can challenge findings through the formal objections process at finnrick.com/vendor-support/objections.

Executive summary

Across 3 Finnrick lab tests, YuYi peptide posts a 67% overall pass rate (2 pass / 1 fail). The record is narrow: every test is Retatrutide. The two later passes show YuYi can ship material that clears Finnrick’s public methodology, but the first sample was a critical identity failure reported as containing no Retatrutide. With only one tested product, this is a high-variance Retatrutide signal, not evidence for the wider catalog; stricter methodology views make the small dataset especially fragile.

The non-lab record is also young and hard to reconcile. YuYi markets itself as an established, production-capable business, while GitHub repository metadata, a recent site footprint, and an ECHEMI trading-platform listing point to a much newer public operation. The same records create a manufacturer-versus-trader issue and a location mismatch between the site branding and the third-party listing.

Buyer accountability is the central theme. The observed sales stack runs through a GitHub Pages subdomain, Gmail, and Hong Kong-region WhatsApp/Telegram contacts, with no visible checkout, merchant descriptor, business address, or official-channel list. The site’s COA language points to certificates issued after buyers received goods rather than seller-side release testing by an identified lab. The promotion scan found no affiliate network, coupon pages, or public Reddit discussion; that reduces influencer-amplification risk but leaves little reputation surface to inspect.

Inside the full report:

  • Product-specific Retatrutide analysis, methodology-sensitivity charts, and the full Appendix A lab-data breakdown.
  • Dated evidence timeline comparing website history claims, GitHub repository metadata, and ECHEMI listing signals.
  • Corporate identity review of the GitHub Pages site, Gmail contact, WhatsApp/Telegram stack, and missing payment path.
  • Manufacturer-versus-trader analysis and site-versus-ECHEMI location reconciliation.
  • COA provenance review of the buyer-issued certificate language and unverified lab chain.
  • Promotion and reputation sweep covering X, coupon pages, Reddit/web search, and unresolved dead ends.

Risk assessment

  • Retatrutide quality-failure risk — high: YuYi's only tested product is Retatrutide: 3 tests (2 pass / 1 fail), with the Dec. 29, 2025 sample reported as not containing Retatrutide.
  • Misleading-history risk — high: Site claims over 10 years, while the public web footprint starts in 2025 and ECHEMI lists Yuyipeptide Biotechnology Co., Ltd as established in 2026.
  • Manufacturer-status and source-visibility risk — medium: Marketing presents R&D/production, but ECHEMI classifies the entity as a Trader and site COAs are buyer-issued with no verified lab chain.
  • Verifiable-infrastructure and identity-friction risk — medium: Commercial sales appear to run through GitHub Pages, Gmail, and Hong Kong WhatsApp/Telegram, with no visible payment processor, address, official-channel list, or resolved Yiwu/Henan location match.