NurseLeah_Nash said:COA red flags for certificates of analysis — here's what to look for when reviewing a Certificate of Analysis: No HPLC data: If there's no…
Third-party testing services for certificates of analysis besides Janoshik:
- Janoshik: Gold standard for peptide community, ~$140, 10-14 day turnaround
- Valitech: US-based, ISO 17025 accredited, ~$210
- Eurofins: Full pharmaceutical testing suite, more expensive but comprehensive
- ChemTox: Basic identity and purity testing, ~$120
Janoshik is the community standard but any ISO-accredited analytical lab can verify peptide identity and purity. The key is independence — don't rely solely on the vendor's own testing.
ChrisMacros said:One addition: an unstated method makes a report close to uninterpretable.
Genuinely useful, thank you. I had the facts and not the framework. Printing the relevant bit and taking it with me.
NurseLeah_Nash said:COA red flags for certificates of analysis — here's what to look for when reviewing a Certificate of Analysis: No HPLC data: If there's no…
My HPLC chromatogram analysis for certificates of analysis — I sent my batch to Janoshik and here's what the results showed:
Main peak retention time: 16.2 minutes (consistent with semaglutide reference standard)
Peak purity: 99.8%
Related substances: 0.5% (single impurity at 10.5 minutes — likely a synthesis intermediate)
Mass spec: m/z 4113.5 (matches expected molecular weight)
This is a clean result. The mass spec confirmation is particularly important — it proves the molecule is actually semaglutide and not a substitution.
Sigma-Aldrich — Research-Grade Standards
Certified reference materials, analytical reagents, and research-grade standards for peptide verification. Trusted by laboratories worldwide.
Shop Reference StandardsDr.CardioMD said:Two reports on the same product from two laboratories, four percentage points apart, and no method stated on either.
Community-verified vendors for certificates of analysis: I maintain a spreadsheet of Janoshik-verified test results submitted by community members. Across 47 submitted tests:
- 75% tested at ≥98% purity
- 18% tested at 95-98% purity
- 7% tested at <95% purity (concerning)
The vendors with consistently high purity results are listed in the Vendor Directory. We update monthly based on new community submissions.
Moderator note: a post naming a supplier has been edited. Discuss suppliers in the review sections, not here. Thread quality here is what the rules are for. Keep it up.