What endotoxins are
Endotoxins are lipopolysaccharides (LPS) from the outer membrane of gram-negative bacteria. They are released when bacteria die and break apart.
Unlike live bacteria, endotoxins are not removed by ordinary sterile filtering and are very hard to destroy with heat. So a product can be sterile and still contain endotoxin.
How the test works
The classic method is the LAL test, which uses a reagent from horseshoe crab blood that reacts to tiny amounts of endotoxin. A synthetic version, recombinant factor C, does the same job without animal material.
Results come as endotoxin units, often per milligram (EU/mg). Regulators such as the FDA set endotoxin limits for licensed injectable medicines.
On a certificate
Endotoxin is a separate test from HPLC purity and mass spectrometry. A 99% pure peptide can still carry endotoxin, so it is only covered if the certificate lists it.
Educational information only. Nothing here is medical advice, dosing guidance or a recommendation to use any substance. Research peptides are not approved medicines and are not for human or animal consumption. Speak to a qualified professional and follow the law where you are.
