Peptide Critic Community

Thank you for responding!

The COA is from Onyx. https://onyxresearch.shop/wp-content/uploads/2025/07/Onyx2606230397.pdf

The other information is from research gate. https://www.researchgate.net/figure/Chromatogram-of-optimized-method_fig2_372427976

I’m new to this. I don’t understand everything I’m reading. Is the Onxy Tirzepatide not good? But it seems like every vendor shows the same thing. And the research articles show something different.

Another research paper: https://www.ijpsjournal.com/article/Analytical+Method+Development+and+Validation+of+Tirzepatide+in+Bulk+and+Pharmaceutical+Formulation+by+RPHPLC

Here’s another COA.

https://portal.ils-lab.com/verify/t8nrWIXfiq80U_in

I’m a beginner. I’m researching Tirzepatide. I look at the COAs and see that the Tirzepatide is eluting at 15 min. I’ve read it should elute at 4-8 minutes. So why can’t I find any? Do you guys know of a lab that sells Tirzepatide that elutes at 4-8 minutes ?

Thanks in advance.