The Peptide Sourcing Field Guide
The biggest names in this market keep disappearing. When they do, the question is the same every time: who’s actually legit, and how would you even know? This is how to read a vendor before you trust one. Education, not a recommendation to buy anything.
1. A COA is the floor, not the ceiling
A Certificate of Analysis is a lab report on identity and purity. It is the most cited trust signal and the easiest to fake. A real COA names the lab, a lot number, a test date, and a result you can tie to the exact product. A PDF with no lab name, no lot, or a date that never changes is decoration, not evidence.
- Match the lot on the COA to the lot on the vial.
- Independent labs confirm a real report number.
- A COA from the seller’s own “lab” tells you little.
2. Read the vendor, not the marketing
Product-quality estimates vary sharply by sample, market, and test method, so we do not publish a portfolio-wide failure percentage without a traceable dataset. Provenance matters more than a slick site: independently verifiable lot testing, documented logistics, real returns, a physical address, and language that does not promise to treat or cure.
3. Red flags that should stop you cold
- “DM for a source.”
- Reused or undated COAs.
- Cure/treatment claims (illegal here, and a tell).
- Prices far below everyone else.
- Nothing you can verify independently.
4. What changed after the shortages
FDA ended time-limited enforcement discretion tied to the semaglutide and tirzepatide shortages after determining those shortages were resolved. Compounding eligibility still depends on federal law and patient-specific facts; a “research use only” label does not turn a human-use product into an approved drug.
5. Five questions before you trust a source
- Can I tie a third-party COA to this exact lot?
- Who is the lab, and will they confirm the report?
- What is the batch-testing history, not just one report?
- Does the seller make any treatment or cure claim?
- If something is wrong, is there a real person and policy behind it?
Sources for this guide
- FDA: compounding oversight, compliance actions, and risk alerts (Regulatory source)
- FDA: bulk substances that may present significant safety risks (Regulatory source)
Reviewed August 24, 2026. Educational editorial content; no named clinician review is claimed.
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Subscribe free →Peptidiary is independent education and news, not medical advice. Nothing here is a recommendation to buy, use, or dose any compound. Talk to a qualified clinician about your health.