KevinCompounds 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…

I tested my certificates of analysis batch through Janoshik — 97.0% purity. That's within acceptable range for compounded peptides. Turnaround was 12 business days.

The test costs ~$141 but gives you actual HPLC chromatography data plus mass spec confirmation. For the peace of mind alone, it's worth every penny. I test every new batch from a new vendor.

pete_RVA said:

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

Bookmarking. The distinction being drawn above is the one nobody else makes.

KevinCompounds 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 6 times from my current compounder. Consistency has been excellent.

Shipping: 3-day with temperature monitor
Packaging: Professional, discreet, proper labeling with lot/batch numbers
Purity: 98.7% average across orders (Janoshik verified)
Customer service: Responsive within 1 hours
Price: $135/month for tirzepatide 10mg equivalent

Dr.PainCLE 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…

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

• Janoshik: Gold standard for peptide community, ~$139, 10-14 day turnaround
• Valitech: US-based, ISO 17025 accredited, ~$249
• Eurofins: Full pharmaceutical testing suite, more expensive but comprehensive
• ChemTox: Basic identity and purity testing, ~$109

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.

Moderator note: a couple of off-topic posts removed.