QSC Peptidology
QSC Peptidology
Manufactured in China

You're buying from the lab,
not the middleman.

QSC Peptidology is the brand of QSC Sigma Limited, a research-peptide manufacturer based in China. We synthesize, purify, lyophilize and ship every vial ourselves — direct from the facility that makes it, not a reseller.

This online store is operated by QSC Sigma Limited.

8Years synthesizing
1,200 m²GMP-grade facility
14Synthesis chemists

From synthesis to your lab door

Six steps. Every vial in the catalog has been through all of them. The chromatogram you download with your order is from the actual batch in your hand — not a sample.

1

Solid-phase peptide synthesis

Resin-bound assembly using Fmoc chemistry. Each amino acid coupling is monitored by Kaiser test.

CSBio CS136X automated synthesizer

2

Cleavage and crude precipitation

TFA cleavage cocktail releases the peptide; cold diethyl ether precipitates the crude product.

3

Preparative HPLC purification

Reverse-phase chromatography on C18 column. Only fractions ≥99% purity move forward.

Waters Prep 150 LC · C18 50×250 mm

4

Lyophilization

Sterile-filtered solution is shell-frozen and lyophilized in glass vials at −60°C under vacuum for 48 hours.

SP Scientific VirTis Genesis 25EL

5

Analytical HPLC + LC-MS QC

Every finished batch is verified again on analytical HPLC and confirmed by LC-MS. Independent third-party re-testing is available per batch on request.

Agilent 1260 Infinity II · Bruker amaZon SL

6

Pack and ship

Vials are sealed under nitrogen, insulated for transit, and dispatched via DHL, UPS, or FedEx.

What "QC passed" actually means

A batch can't ship until it clears all four checks. If any fail, the entire batch is rejected — we don't blend, we don't ship partial.

HPLC purity

Reverse-phase HPLC at 220 nm. Cutoff: 99.0% main peak.

≥ 99.0% required

Mass spectrometry

LC-MS verifies the molecular weight matches theoretical within ±0.5 Da.

m/z match confirmed

Endotoxin (LAL)

Limulus amebocyte lysate test for bacterial endotoxin contamination.

< 1 EU/mg required

Third-party testing (Janoshik)

Not run on every batch. Janoshik Analytical has tested sample vials of retatrutide, tirzepatide, semaglutide and BPC-157, and the reports are public. Test any batch yourself and we return the test fee as account credit.

View Janoshik reports →

Manufacturer-direct, transparent pricing

Most US “peptide brands” are resellers. They buy from facilities like ours and sell to you. Here's what changes when you skip the middle layer.

What you gain

  • Manufacturer-direct pricing, no reseller markup
  • Custom orders & longer peptides on request (5–20 day lead time)
  • Wholesale & private-label supply for labs and distributors buying by the kit

What you trade off

  • Shipping is 10–15 days, not 1–2 (China → US, via DHL/UPS/FedEx)
  • Transit conditions depend on the courier network — we cover issues, but they happen
  • US customs occasionally holds shipments for 2–5 extra days