Clinical perspective, offered as context rather than as advice.

I tested my certificates of analysis batch through Janoshik — 99.2% purity. That's within acceptable range for compounded peptides. Turnaround was 10 business days.

The test costs ~$146 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.

DeniseRN_TPA said:

I tested my certificates of analysis batch through Janoshik — 99.2% purity.

Vendor quality matters when discussing certificates of analysis. I've tested my last 3 batches through Janoshik and purity has ranged from 98.4% to 99.4%. Consistency is key.

For anyone new: always request the COA, and consider independent verification. The $300 for a Janoshik test is worth the peace of mind.

DeniseRN_TPA said:

I tested my certificates of analysis batch through Janoshik — 99.2% purity.

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.

DeniseRN_TPA said:

I tested my certificates of analysis batch through Janoshik — 99.2% purity.

This answered a question I did not know how to ask. Printing the relevant bit and taking it with me.

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