Paid for independent testing and results did not match vendor COA — looking for input

sean_dublin said:

Inter-laboratory variation comes from real methodological differences, not sloppiness: which reference standard was used and how it was itself…

sean_dublin has the substance of this right. The condition it depends on is worth stating. One addition: an unstated method makes a report close to uninterpretable. "99% pure" without the technique, the standard and the conditions is a claim, not a measurement.

Correct me if the detail matters more than I have assumed.

steph_laguna said:

Right, and one flattering data point from a group buy is not consistency.

This answered a question I did not know how to ask. Taking it to my next appointment.

sean_dublin said:

Inter-laboratory variation comes from real methodological differences, not sloppiness: which reference standard was used and how it was itself…

I am more sceptical of certificates as a category than this thread is. The document tells you about a sample somebody chose to send, at a moment in time, and nothing about the vial in your hand. Independent purchase-and-test is a different quality of evidence and everything else is inference.

PurityPaulOR said:

Eight months with one supplier, then a change in how they communicate that I noticed before I noticed anything about the product.

Shipping damage protocol for vendor vetting orders: if your package arrives with visible damage, temperature excursion, or broken vials:

• Photograph EVERYTHING before discarding packaging
• Note the temperature of the cold pack (liquid = possibly too warm)
• Contact the vendor within 24 hours with photos
• Request a replacement shipment or refund
• Do NOT use potentially compromised medication

Reputable vendors will replace damaged shipments without argument. If they push back, that's a red flag about the vendor.

Moderator note: a couple of off-topic posts removed. Tagging this one for the weekly digest.