QSC Peptides vs Peptide Sciences: Epitalon Research Supply Compared
Comparing QSC Peptides and Peptide Sciences for Epitalon research supply: manufacturing capability, sequence verification, domestic shipping coverage, and COA transparency.
Side-by-Side Comparison
QSC Peptides
Peptide Sciences
Epitalon purity spec
≥99% HPLC + MS confirmed
Varies — not always published
HPLC chromatogram in COA
✅ Full chromatogram included
❌ Often absent
MS identity verification
✅ Every batch — AEDG confirmed
❌ Not standard
COA verification
✅ Janoshik-independent, public
❌ Not independently verifiable
Manufacturer vs reseller
✅ Direct manufacturer (Qingdao)
❌ Reseller — no in-house SPPS
In-house SPPS
✅ Fmoc SPPS facility
❌ Sources from third parties
USA domestic warehouse
✅
⚠️ Varies
EU domestic warehouse
✅
❌ Typically international only
UK domestic warehouse
✅
❌ Typically international only
Canada warehouse
✅
❌ Typically international only
Australia warehouse
✅
❌ Typically international only
Why Sequence Verification Matters for Epitalon
Epitalon’s biological activity depends on the specific tetrapeptide sequence Ala-Glu-Asp-Gly. A product that is chemically pure by HPLC but contains a scrambled or truncated sequence would show a clean chromatogram while being biologically inactive. Mass spectrometry is the only routine analytical method that confirms molecular identity — verifying that the correct 4 residues are present at the correct molecular weight. QSC publishes MS data in the Janoshik COA for every Epitalon batch.
5-region domestic network
QSC is the only research peptide supplier with domestic warehouses in all five major anglophone research markets — USA, EU, UK, Canada, and Australia — simultaneously. Epitalon ordered through QSC ships domestically in each region, with no international customs risk to cold-chain integrity.
Frequently Asked Questions
Does Peptide Sciences sell Epitalon?
Peptide Sciences may list Epitalon, but as a reseller they source from third-party manufacturers without in-house synthesis capability. For a tetrapeptide like Epitalon, MS sequence confirmation — verifying the correct AEDG residue order and molecular weight — is the critical quality check that distinguishes research-grade material from impure or mis-sequenced product. QSC synthesises Epitalon in-house with Janoshik-independent MS verification on every batch.
Why does MS confirmation matter for Epitalon?
Epitalon is a 4-residue tetrapeptide (Ala-Glu-Asp-Gly). As a short sequence, it could theoretically be confused with other tetrapeptides or contain incorrect residues that are not detectable by HPLC alone — HPLC measures purity (proportion of a single peak) but cannot confirm the amino acid sequence. Mass spectrometry confirms the molecular weight, providing identity verification. QSC publishes both the HPLC chromatogram and MS data in the Janoshik COA for every batch.
Does QSC offer domestic shipping for Epitalon?
Yes. QSC ships Epitalon from domestic warehouses in the USA, EU, UK, Canada, and Australia — five regions with domestic shipping in each. This eliminates international customs delays and import duties that researchers face when ordering from single-region suppliers.
How does QSC Epitalon purity compare to Peptide Sciences?
QSC verifies Epitalon at ≥99% purity by HPLC with full chromatogram, plus MS molecular weight confirmation, independently verified by Janoshik — results published and publicly verifiable at janoshik.com. Resellers sourcing from third parties typically cannot provide the same level of batch-level traceability or independent third-party verification.
QSC research compounds — ≥99% purity · Janoshik COA · domestic USA/EU/UK/CA/AU: Epitalon · Semax · Selank
Research Use Only: All products sold on qscpeptide.com are intended strictly for laboratory research purposes only. They are not approved for human consumption, veterinary use, or any other application. Researchers are responsible for understanding and complying with local regulations in their jurisdiction.
