Jul 14, 2024 at 6:36 PM#21
One thing that is still open after Dr.NateNeph’s answer:
What did you change at the same time, and can you separate the two now?
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Jul 16, 2024 at 4:32 AM#22
nancy_portland 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…
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: 100.3% purity
Day 14: 99.5% 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.
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Jul 17, 2024 at 2:27 PM#23
nancy_portland 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 vendor review relevant to certificates of analysis: ordered 5 times from my current compounder. Consistency has been excellent.
Shipping: Same-day local pickup
Packaging: Professional, discreet, proper labeling with lot/batch numbers
Purity: 97.6% average across orders (Janoshik verified)
Customer service: Responsive within 6 hours
Price: $150/month for semaglutide 2.4mg equivalent
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Sigma-Aldrich — Research-Grade Standards
Certified reference materials, analytical reagents, and research-grade standards for peptide verification. Trusted by laboratories worldwide.
Shop Reference StandardsJul 19, 2024 at 12:21 AM#24
nancy_portland 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…
Thank you for spelling out the reasoning rather than just the conclusion. Adding it to my notes with a link back to this thread.
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Jul 20, 2024 at 10:14 AM#25
Adding the clinical framing, because it changes how the question reads.
Mass spectrometry confirmation for certificates of analysis: beyond HPLC purity, mass spec tells you the molecule's exact molecular weight. This confirms identity — not just purity.
Why this matters: HPLC can show you a "pure" compound, but if it's pure of the WRONG compound, purity is meaningless. Mass spec at m/z 4113.58 Da confirms it's actually semaglutide. My Janoshik report includes both HPLC and mass spec.
If your testing provider only offers HPLC, consider upgrading to include mass spec for at least your first batch from a new vendor.
Last edited: Jul 20, 2024 at 1:14 PM
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