Adding the clinical framing, because it changes how the question reads.

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 chromatography graph, it's not a real COA
• Exact 100% purity: Suspicious — real testing always shows slight variation
• No batch number: Can't trace back to specific production
• No endotoxin testing: For injectables, this is essential
• Template looks like it was made in Word: Professional labs have standardized formats

I have seen fake COAs that are literally photoshopped. Always verify independently if possible.

Dr.PulmRoch said:

Vendor quality matters when discussing certificates of analysis.

Third-party testing services for certificates of analysis besides Janoshik:

• Janoshik: Gold standard for peptide community, ~$129, 10-14 day turnaround
• Valitech: US-based, ISO 17025 accredited, ~$229
• Eurofins: Full pharmaceutical testing suite, more expensive but comprehensive
• ChemTox: Basic identity and purity testing, ~$119

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.

Dr.PulmRoch said:

Vendor quality matters when discussing certificates of analysis.

Reconstituted peptide stability data for certificates of analysis: I had Janoshik test my reconstituted vial at day 1, day 14, and day 28 stored in the refrigerator.

Day 1: 100.1% purity
Day 14: 99.1% purity
Day 28: 98.1% purity

Minimal degradation over 28 days when properly refrigerated. This confirms the standard 28-day beyond-use date is appropriate. Beyond 28 days, I'd reconstitute a fresh vial to be safe.

A narrower follow-up, since the general answer is now clear:

Was that from a primary source or from a summary of one?

Moderator note: a post naming a supplier has been edited. Discuss suppliers in the review sections, not here.