JenPlateau said:

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:…

Adding a me-too, because a thread of one person's experience is not much use. The detail I would add is minor and it is already implied above.

anders_CPH said:

My vendor review relevant to certificates of analysis: ordered 6 times from my current compounder.

Vendor quality matters when discussing certificates of analysis. I've tested my last 5 batches through Janoshik and purity has ranged from 98.0% to 99.2%. 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.

One thing that is still open after anders_CPH’s answer:

Did your prescriber agree with that reading, and if not what was their objection?

Dr.RaviCardio said:

Vendor quality matters when discussing certificates of analysis.

Community-verified vendors for certificates of analysis: I maintain a spreadsheet of Janoshik-verified test results submitted by community members. Across 46 submitted tests:

• 82% tested at ≥98% purity
• 12% tested at 95-98% purity
• 6% tested at <95% purity (concerning)

The vendors with consistently high purity results are listed in the Vendor Directory. We update monthly based on new community submissions.

Moderator note: reminder that nothing in this thread is medical advice, and that clinical claims need a source. No action needed from anybody.