I'm not diving into the chemistry details, but as a medical professional I can say this does not contradict basic pharmacology. People respond differently to any medication, even at the same dose from the same maker. We expect broadly similar outcomes, yet thousands of biological and environmental factors shape each person's reaction.
Everyone repeats that tirz is just tirz, but the shared view is that people react differently and even different compounders' versions act differently. That clashes with pharmacology basics for generics and with chemistry. Apart from getting shorted on milligrams from mistakes or breakdown, what scientific reason supports the belief? Explain it like I'm five but a very demanding five. I've read semi-technical forum posts suggesting the same API could still be different somehow, yet it's never been clear chemically what that would mean. Maybe HPLC fails to separate very similar molecules? If so, how does that still confirm identity? I'd like chemistry-level answers using ideas like electrons, orbitals or conformation, perhaps a theoretical example, instead of general statements.