How to Evaluate a Research Peptide Supplier
A seven-point framework for researchers choosing between third-party peptide suppliers.
The Seven-Point Checklist
- Third-party Certificate of Analysis (COA) — Every batch should ship with a COA issued by an independent laboratory, not the vendor itself.
- HPLC purity ≥ 99% — The gold standard for research-grade peptides. Ask to see the chromatogram, not just a summary number.
- US-based shipping & cold-chain logistics — Peptides degrade in transit; reputable US suppliers use temperature-controlled shipping for sensitive compounds.
- GMP-sourced raw materials — Good Manufacturing Practice assurance on upstream sourcing reduces the risk of contamination.
- Clear batch labeling — Lot number, synthesis date, storage instructions, and expiration should be legible on every vial.
- Responsive customer service — A quick response to a pre-purchase question is the single best predictor of post-purchase problem resolution.
- Transparent refund & return policy — Published policies for contamination, breakage, and research-use documentation issues.
Red Flags to Avoid
- No COA, or a COA that is dated months before the batch
- Purity claims without a published chromatogram
- Overseas-only shipping with no cold-chain provision
- Unresponsive or generic customer service channels
- Marketing language promising medical outcomes (a signal that research-use framing is not respected)