MMK Peptide LabsMMK Peptide LabsEndotoxin units, LAL assays, and how to read the numbers on a lab report.
A purity percentage and an endotoxin number answer two different questions. This guide explains what endotoxin is, how it is measured, and how to read the way results are written.
Endotoxins are lipopolysaccharide (LPS) molecules that make up part of the outer membrane of Gram-negative bacteria. They can remain in a material after the bacteria that produced them are gone, so a sample can carry endotoxin even when it contains no living bacteria.
Endotoxin is commonly measured with LAL-type assays. LAL stands for Limulus amebocyte lysate, a reagent that reacts to endotoxin; recombinant alternatives based on the same reaction also exist. Several formats are in use (gel-clot, turbidimetric, chromogenic). Results are given in endotoxin units (EU), a unit of activity rather than of weight. A report should name the method it used.
HPLC purity describes how much of the analyzed material is the target compound. Endotoxin is present in extremely small mass amounts, so it does not show up as a meaningful change in a purity percentage. A sample can therefore show a very high purity and still carry measurable endotoxin, which is why a separate test is used. Research buyers who care about cell-based or sensitive assays often ask for both numbers.
When comparing reports, make sure the units match, and that the sample on the report is the product you are looking at.
MMK lists two separate third-party Janoshik reports for BC10:
The two numbers come from two different tests with two different test numbers. One tells you about the share of target compound; the other about endotoxin. Neither replaces the other. Compare that with Retatrutide 30mg, whose endotoxin report reads <1 EU/vial. Product page: BPC-157 10mg.
MMK has posted endotoxin reports only for the products on its lab reports page; not every product has one.
Endotoxin is lipopolysaccharide (LPS) from the outer membrane of Gram-negative bacteria. It can remain in a material even after the bacteria are gone.
Commonly with LAL-type assays (Limulus amebocyte lysate or recombinant equivalents), in formats such as gel-clot, turbidimetric or chromogenic. Results are reported in endotoxin units (EU).
Yes. HPLC purity measures the share of the target compound, while endotoxin is present in tiny mass amounts that barely change a purity percentage. That is why it is tested separately.
The "<" sign means the result was below the level the method could report. It does not mean exactly zero.
EU/vial is endotoxin in the whole vial; EU/mg is per milligram of material. Divide the per-vial value by the amount in the vial to compare them.