Endotoxin on Trial: Massive Review Finds Experimental Inflammation Shots

Researchers at Purdue University report, in a new scoping review, that the experimental “endotoxemia” model—injecting purified bacterial toxin LPS into healthy volunteers—appears broadly safe under modern protocols. Published in BMC Pharmacology and Toxicology, the review examined studies from January 2006 onward, after earlier case reports of rare sinus pauses that followed intravenous LPS administration led to added precautions. Using PRISMA Extension for Scoping Reviews and a PubMed search, the team found 165 distinct clinical studies involving 3,870 volunteers out of an initial 252 articles. Participants were mostly healthy young adults with a mean age of about 28.3 years, and 117 of 165 studies enrolled only men, limiting how widely the safety conclusions can be generalized. The review explains that LPS activates Toll-like receptor 4 and triggers measurable immune and physiological responses.