Peptide COA Endotoxin Discrepancy + No Response - WARNING

[mcs]

Quick PSA for anyone using Verfiied Peptides (VP).

I initially chose VP as what looked to be a suitable replacement for the now-defunct Peptide Sciences. They are one of the few RUO/UGL suppliers that publish COAs which include the much-needed endotoxin (LAL) testing in addition to HPLC potency/purity analysis.

I’ve therefore been running independent endotoxin (LAL) testing on vials after a prior LPS incident.

VP Result (Independent Test)

• • Method: Kinetic turbidimetric LAL (MZ BioLabs)
• • Avg: 1.777 EU/mL
• • Total: 3.554 EU → POSITIVE

What VP Shows

• • COAs (where available): typically ≤0.05 EU/mL (PASS)
• • No updated COAs reflecting this discrepancy

Communication

• • Multiple emails sent
• • Follow-ups sent
• • Zero response

Takeaway

That’s a ~35x difference vs the typical ≤0.05 EU/mL spec—and no engagement from VP to explain it.

For injectables, that’s a hard stop for me.

More testing pending on other VP vials as well as on other suppliers (I also use Finnrick). Will update.

 

[Nelson Vergel]

I’ve therefore been running independent endotoxin (LAL) testing on vials after a prior LPS incident.

Thanks for this info. Where did you get testing done? Can you expand for all of us?

 

[mcs]

Thanks for this info. Where did you get testing done? Can you expand for all of us?

MZ Biolabs

 

[BadassBlues]

I appreciate the heads up, but without the actual test results being posted it has no merit.

 

[mcs]

I appreciate the heads up, but without the actual test results being posted it has no merit.

I appreciate the heads up, but without the actual test results being posted it has no merit.

Quick clarification to my prior post.

The endotoxin (LAL) result I shared is from one tested vial of Thymagen 20mg (independent lab, kinetic turbidimetric LAL):

• Avg: 1.777 EU/mL
• Total: 3.554 EU → POSITIVE

Important limitation: the vial tested does not have a lot/batch number, and the lab report does not reference a lot either. Because of that, I cannot definitively link this result to a specific batch or published COA.

So this should be interpreted as:

• a single-sample result, and
• a general caution regarding traceability

I currently have multiple additional samples (from several vials) out for testing to 2 labsd. Turnaround is a few weeks, and I’ll post those results as they become available.

Not making any broad claims—just sharing data and context.