Peptide Supplier Verification Checklist
Not all peptide suppliers are equal. Before trusting your research to any vendor, use this comprehensive checklist to verify their quality standards, documentation practices, and business legitimacy.
Research peptide quality varies dramatically between suppliers. Poor-quality peptides can ruin experiments, waste resources, and produce unreliable data. Taking time to verify a supplier before purchasing protects your research investment.
This guide provides a systematic approach to evaluating peptide suppliers, with specific criteria to check and red flags to avoid.
Why Supplier Verification Matters
Research Validity
Impure or mislabeled peptides produce unreliable results. Your data is only as good as your materials.
Cost Efficiency
Cheap, low-quality peptides often cost more in the long run when experiments need to be repeated.
Reproducibility
Consistent quality between batches is essential for reproducible research across multiple experiments.
Publication Quality
Peer review increasingly expects documentation of material sources and quality verification.
Complete Verification Checklist
Testing & Documentation
- Third-party testing (not in-house only)Critical
- Batch-specific COAs (not generic)Critical
- HPLC purity results includedCritical
- Mass spectrometry identity verificationCritical
- Named, verifiable testing laboratory
- Full chromatogram images provided
Purity & Quality Standards
- Minimum 98% purity (preferably ≥99%)Critical
- Consistent purity across batches
- Proper lyophilization (not liquid)
- Appropriate packaging (sealed, light-protected)
Business Legitimacy
- Physical business address (verifiable)Critical
- Contact phone number (answered)
- Professional website with detailed information
- Clear return/refund policy
- Responsive customer service
Shipping & Handling
- Cold chain shipping available
- Discrete, professional packaging
- Tracking provided
- Domestic shipping (reduces transit time)
Reputation & Reviews
- Verifiable customer reviews
- Active in research communities
- No significant complaints/warningsCritical
- Established track record (1+ years)
Red Flags to Avoid
If you encounter any of these warning signs, proceed with extreme caution or avoid the supplier entirely:
- No COA or only generic/template COAs
- In-house testing only with no third-party verification
- Unusually low prices (significantly below market)
- No physical address or only P.O. box
- Vague or evasive about testing methods
- Medical/therapeutic claims (indicates regulatory ignorance)
- No contact information or unresponsive
- Negative reviews mentioning purity issues
- Pressure tactics or 'limited time' offers
- No return policy or refuses to discuss quality issues
Questions to Ask Suppliers
"Can you provide batch-specific COAs?"
A quality supplier will provide COAs that match your specific lot number, not generic documents.
"Which third-party lab performs your testing?"
They should be able to name the laboratory. You can then verify the lab exists and is accredited.
"What is your minimum purity standard?"
Look for suppliers who guarantee minimum 98% purity, ideally ≥99% for research applications.
"What is your return policy for quality issues?"
Reputable suppliers stand behind their products and have clear policies for addressing concerns.
BioInfinity Lab Standards
At BioInfinity Lab, we exceed every item on this checklist:
- ≥99% Purity Guarantee on all products
- Independent Third-Party Testing on every batch
- Batch-Specific COAs with HPLC and MS verification
- Public COA Library - verify before you buy
- USA-Based Operations with verified addresses
- Same-Day Shipping with tracking on all orders