⭐ VERIFIED VENDOR LIST — WWB, GGPeps (GYC), QSC — Updated June 2026
This list is maintained by the moderation team and it records one thing only: which suppliers members have independently tested, and how consistently the results held. It is a record, not a recommendation.
On the list
| Supplier | Mean purity | Independent tests on file | Standing |
|---|---|---|---|
| QSC (Qingdao Sigma Chemical) | 97.3% | 56 · Janoshik | Listed |
| WWB (Wuhan Wansheng Bio) | 96.5% | 7 · Janoshik | Listed |
| GGPeps (Nantong Guangyuan) | 96.8% | 11 · Janoshik and PeptideMeter | Listed |
What being listed does and does not mean
- Does mean: more than one member has paid for a test, on more than one batch, over months, and posted the report.
- Does mean: no unresolved scam report and no unanswered quality complaint at the time of review.
- Does not mean that the batch in your hand is the batch that was tested. It is not, and nobody can tell you otherwise.
- Does not mean endorsement. This board sells nothing, brokers nothing, and takes nothing from anyone on this list.
A supplier comes off the list the moment a quality question goes unanswered, and a removal is recorded rather than quietly done. If you have a test result — good or bad — post it in the review sections and it will be counted.
Reviewed monthly.
Janoshik Analytical — Independent Testing
Trusted third-party HPLC & mass spectrometry analysis. Verify peptide purity with the lab the community relies on. Independent. Accurate. Transparent.
Verify Your PeptidesGL Biochem (Shanghai) Ltd. — Direct Manufacturer
Est. 1998. The synthesis house behind the vials you send for testing. ISO 9001 and cGMP certified, 1,500+ staff, batch-specific COA with every order.
Browse GL Biochem