Understand the source comparison
Biggest Peptide Myths Debunked Science: Supplier Comparison
'Pharmaceutical grade' No regulatory definition for research peptides. Term is marketing only Request GMP certification or FDA registration proof (most can't provide it) Implies regulatory oversight that doesn't exist for research-only compounds Reject supplie
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- 'Pharmaceutical grade'
- No regulatory definition for research peptides. Term is marketing only
- Request GMP certification or FDA registration proof (most can't provide it)
- Implies regulatory oversight that doesn't exist for research-only compounds
- Reject suppliers using this term without GMP documentation. It's a red flag
- 'Highest purity available'
- HPLC purity ≥95% is standard; ≥98% is achievable but not universal
- Demand third-party COA with HPLC chromatogram and mass spec confirmation
- Purity below 95% increases risk of sequence-related impurities (deletion peptides, oxidized variants) that alter experimental outcomes
- Verify purity claim matches actual HPLC data. Vague claims without data are worthless
- 'Made in USA'
- Synthesis location =/= quality; China and India produce high-purity peptides under proper protocols
- Ask for synthesis facility certification and batch traceability records
- Geography doesn't determine quality. Synthesis SOPs and QC testing do
- Focus on testing rigor, not synthesis location. U.S. labs cut corners too
- 'Guaranteed potency'
- Potency degrades post-synthesis; guarantee is only valid at manufacture date
- Request COA date and compare to purchase date. Peptides degrade over time
- A 6-month-old peptide stored improperly has lower bioactivity than a fresh batch
- Batch date matters more than supplier guarantee. Reject old inventory
- 'Bulk pricing = same quality'
- Larger batches are harder to synthesize at high purity; economies of scale often mean purity trade-offs
- Compare COAs across batch sizes from same supplier. Purity should be consistent
- Cost reduction through purity compromise is common in bulk synthesis
- Verify purity consistency across order volumes. Price cuts shouldn't mean quality cuts