claudia_zurich said:They are not contradictory, they measure different things, and this is the single most common misreading of a certificate.
That reframing is the part I needed.
Adding the clinical framing, because it changes how the question reads.
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: 99.5% 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.
Dr.RaviCardio said:I tested my certificates of analysis batch through Janoshik — 98.4% purity.
Third-party testing services for certificates of analysis besides Janoshik:
- Janoshik: Gold standard for peptide community, ~$126, 10-14 day turnaround
- Valitech: US-based, ISO 17025 accredited, ~$206
- Eurofins: Full pharmaceutical testing suite, more expensive but comprehensive
- ChemTox: Basic identity and purity testing, ~$116
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.
Sigma-Aldrich — Research-Grade Standards
Certified reference materials, analytical reagents, and research-grade standards for peptide verification. Trusted by laboratories worldwide.
Shop Reference StandardsRunnerRach said:The provenance questions are more useful than the numbers.
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.