Inside uzorak.com, a peptide testing lab in Zagreb, Croatia

This is a summary of my interview with Alex, co-founder of Uzorak, a new peptide testing lab based in Zagreb, Croatia, planning to operate globally.Alex comes from a health-tech background, including a DNA analytics company , and says his own peptide research is what pushed him into building a testing lab. His core argument is simple: in an unregulated market, testing standards should be higher, not lower. He believes people are going to use these compounds regardless, so harm reduction starts with better information about what’s actually in the vial.Uzorak’s offering goes beyond the standard “HPLC-UV purity + mass confirmation” COA. Their “Advanced LCMS Peptide Analysis” is positioned as a bundled package: high resolution LC-MS, impurity identification and quantification, MS/MS sequence confirmation, and tandem MS fingerprinting to check for structural damage versus a reference. They also add a scoring model with published weights, purity, potency, and integrity, plus risk triggers, and they separate “alteration” signals like oxidation and deamidation from “hazard” categories like hydrolysis, cleavage, and synthesis residues.One of the big clarifications in the interview is language: “structure” here doesn’t mean 3D protein folding. Alex notes that folding becomes relevant for large biologics like interferon, filgrastim, or erythropoietin, but for GLP-class peptides, they’re focused on identity, sequence integrity, and detectable chemical modification.We also talked about thresholds and risk messaging. Uzorak presents specific warning triggers, and Alex described red-level findings as potentially more serious, while also acknowledging that analytical flags are not the same thing as clinical diagnosis. They are not ISO/IEC 17025 accredited yet, but say they follow many of the principles where applicable. Sterility, endotoxin, and heavy metals aren’t included by default currently, though an ICH Q3D-aligned heavy metals panel is planned.Bottom line: this interview focuses on analytical substance, not surface - level claims. It’s about whether grey market testing evolves beyond a reassuring purity percentage into a more complete picture , what’s in the peak, what’s outside it, what’s degraded, and what the limits of testing still are.www.uzorak.com