Eli Lilly and Company Sets the Gold Standard for Sustainable Endotoxin Testing

Since 2016, Eli Lilly has led the industry in adopting synthetic alternatives for endotoxin testing:

“In 2016, we drew a line in the sand and began converting to rFC [a synthetic alternative to Factor C]. In 2018, we received approval for our first official medicine using rFC testing. From there, we used it for at least eight other approvals, globally. And we don’t plan to go back.” – Eli Lilly and Company, November 22, 2024

From a conservation perspective, the pharmaceutical giant has set the gold standard for sustainable drug safety testing, an aspect of drug and vaccine manufacturing that has historically been devastating for coastal ecosystems in the eastern U.S. 

Since the 1970s, a critical component of drug and vaccine safety testing has been Factor C, a protein unique to the blood of horseshoe crabs. To harvest this protein, horseshoe crabs are caught, bled alive and then returned to sea. Those that survive the bleeding process (up to 30% do not) are often too weak to reproduce for the remainder of their lives. In 2023, 1.1 million horseshoe crabs were bled for pharmaceutical purposes.

The rapid growth of the injectibles market in recent years, especially with the rise of diabetes and GLP-1 inhibitors for weight loss, has decimated the American horseshoe crab population and the ecosystems that rely on this ancient species. There have been synthetic alternatives to Factor C for decades, but only Eli Lilly has made the transition to these non-animal-derived alternatives for drug safety testing.

Thanks to an initiative with our partners at the Horseshoe Crab Recovery Coalition and the Center for Biological Diversity, we now have a tool for tracking progress across the pharmaceutical industry and for highlighting other companies moving towards full adoption of synthetic alternatives for drug and vaccine safety testing. 

The Sustainability Scorecard

The Sustainability Scorecard for Endotoxin Testing measures and tracks the pharmaceutical industry’s adoption of synthetic alternatives to horseshoe crab blood. In addition to Eli Lilly, 50 of the largest drug companies were invited to participate in the Scorecard via survey about their endotoxin testing methodologies and plans to adopt synthetic alternatives. 

Eli Lilly and Company earned 75%, which is the highest score of submitted surveys, equivalent to a sustainability rating of four out of five horseshoe crabs. View the company’s full survey results here. 

Eli Lilly’s score of 75/100 points means that they have adopted synthetic alternatives for lab water testing (which is where ~80% of horseshoe crab blood is used in drug safety testing), and most importantly, the company has a roadmap to eventually phase out horseshoe crab blood entirely from their drug manufacturing process. 

Learn more about the Sustainability Scorecard including the companies that were invited to participate, the survey questions, and the driving forces behind the project’s creation: www.pharmascore.org.