Has anyone dealt with are all coas created equal? mine looks different from others i see?

MASHdoc_SA said:

HPLC results interpretation for certificates of analysis: when you get your Janoshik report back, here's what the numbers mean: Purity %: Should be…

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

• Janoshik: Gold standard for peptide community, ~$131, 10-14 day turnaround
• Valitech: US-based, ISO 17025 accredited, ~$211
• Eurofins: Full pharmaceutical testing suite, more expensive but comprehensive
• ChemTox: Basic identity and purity testing, ~$121

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.

ben_calgary said:

One addition: an unstated method makes a report close to uninterpretable.

That reframing is the part I needed.

MASHdoc_SA said:

HPLC results interpretation for certificates of analysis: when you get your Janoshik report back, here's what the numbers mean: Purity %: Should be…

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: 16.3 minutes (consistent with semaglutide reference standard)
Peak purity: 98.8%
Related substances: 0.5% (single impurity at 10.2 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.

mel_PDX said:

I have a certificate reporting 99.2% purity and 6.1mg content on a vial sold as 5mg, and I cannot work out whether those two numbers are consistent or…

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: 98.6% average across orders (Janoshik verified)
Customer service: Responsive within 6 hours
Price: $134/month for tirzepatide 10mg equivalent

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