BALTIMORE— A new scorecard ranks the top pharmaceutical companies by their transition away from horseshoe crab blood used in drug safety testing. Horseshoe crab blood is used to detect toxins in a drug or vaccine but a synthetic alternative is safer and more reliable. Nine companies are already transitioning to synthetics.

“These companies are proving that using synthetics instead of horseshoe crabs’ blood is a smart and strategic business decision,” said Will Harlan, a senior scientist at the Center for Biological Diversity. “Rather than depend on a dwindling supply of imperiled horseshoe crabs, companies are improving the security of their supply chains by using safer and more reliable synthetics.”

Nearly twice as old as dinosaurs, horseshoe crabs are brown, body-armored arthropods with 10 eyes and a long spiked tail. Every year more than 1 million horseshoe crabs are harvested for use by the pharmaceutical industry to test drugs and vaccines. As a result, horseshoe crab populations have crashed. A recent petition is seeking to have them protected under the Endangered Species Act.

Synthetic alternatives to horseshoe crab blood have been available since 1995 and are already widely used in Europe. Newly adopted U.S. guidelines officially recognized synthetics as effective and safe for detecting contaminants in injectable drugs and vaccines. Now pharmaceutical industry leaders in the United States are racing to adopt synthetic alternatives.

“We’re witnessing the beginning of a pivotal transformation in pharmaceutical manufacturing,” said Ryan Phelan, co-founder and executive director of Revive & Restore. “Industry leaders are already proving that we can enhance drug safety testing and keep up with growing demand while protecting a species that has survived for 450 million years.”

Major surges in vaccine manufacturing and the popularity of new weight loss and diabetes drugs have led to increased demand for horseshoe crab blood, further depleting horseshoe crab populations. Limitless supplies of synthetics can be manufactured in a laboratory that are more dependable, consistent and cost-efficient.

Topping the new scorecard is Lilly, which has already transitioned 80% of its safety testing to synthetics. GSK has also emerged as an industry leader in transitioning away from horseshoe crab blood. The scorecard, which tracks the world’s 50 largest pharmaceutical companies, was developed by Revive & Restore, the Horseshoe Crab Recovery Coalition and the Center for Biological Diversity.

“We are excited to see the progress being made by companies that are embracing synthetic endotoxin solutions,” said David Mizrahi, vice president at New Jersey Audubon. “Their actions will save thousands of horseshoe crabs a year, protecting shorebirds and coastal ecosystems, while also providing supply chain stability and ensuring patient safety. It’s a powerful and responsible step forward.”