Why Supplier Selection Matters
The quality of your research peptides directly impacts your experimental outcomes. A reliable supplier ensures consistency, purity, and proper handling from synthesis to delivery.
Key Evaluation Criteria
1. Third-Party Testing
The gold standard is independent laboratory verification. Look for suppliers who provide Certificates of Analysis (COAs) from accredited third-party labs, not just in-house testing.
2. Testing Methodology
- HPLC — For purity verification (should be ≥98%)
- Mass Spectrometry — For molecular weight confirmation
- Endotoxin Testing — Critical for in vivo research
- Microbial Testing — Ensures sterility
3. Documentation Quality
COAs should include batch numbers, test dates, actual chromatograms or spectra (not just numbers), and the testing laboratory's information.
Red Flags to Avoid
- No COAs available or only generic templates
- Prices significantly below market rates
- Vague or missing contact information
- No physical address or customer service
- Claims of "pharmaceutical grade" for research peptides
If It Seems Too Cheap...
Peptide synthesis is expensive. Dramatically low prices often indicate lower purity, improper storage, or outright counterfeits.
Questions to Ask
- Can I see a COA for the specific batch I'll receive?
- What testing methods do you use?
- How are peptides stored and shipped?
- What is your return policy for quality issues?
- Are your peptides made in-house or sourced?