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New Synthetic Horseshoe Crab Blood Could Mean Pharma Won’t Bleed the Species Dry

The “living fossils” have been vital for testing intravenous drugs, but a few large pharmaceutical companies are using a lab-made compound instead.

Smithsonian Magazine
October 13, 2023

Drug makers promote new toxin testing technology to spare horseshoe crabs

Horseshoe crabs have been living in the ocean for almost half a billion years, surviving five mass extinctions. However, their use in lab tests has put new pressure on these ancient creatures. Drug companies have been trying to change that.

September 5, 2023

Is an end to using imperiled horseshoe crabs for U.S. drug testing in sight?

A draft industry standard could allow synthetic proteins to replace enzyme harvested from East Coast marine animals. The draft guidelines are a “first and important step” toward changing how companies test for dangerous bacterial contamination in their products, says Jaap Venema, chief science officer at USP.

August 25, 2023

The U.S. drug industry is bleeding horseshoe crabs alive. It’s time to stop

Despite the industry’s opaqueness, scientists are beginning to sound the alarm. Horseshoe crabs are likely to feel pain, and they’re too important to the health of their ecosystems to let their numbers continue to dwindle unchecked.

Fast Company
July 13, 2023

Coastal biomedical labs are bleeding more horseshoe crabs with little accountability

Five companies along the East Coast — with operations in South Carolina, New Jersey, Massachusetts, Virginia and Maryland — drained over 700,000 crabs in 2021. Since then, the number of crabs bled by the industry has more than doubled.

June 30, 2023

The problem is that horseshoe crabs are in trouble. Their numbers are declining — “a finite source with potentially infinite demand,” as one pharmaceutical executive told Agence France-Presse last year, “and those two things are mutually exclusive.”

New York Times
February 16, 2023



Red Knots in Steepest Decline in Years, Threatening the Species’ Survival

The best hope for the species to survive lies in a complete ban on harvesting female horseshoe crabs until the crab population recovers, Dr. Niles said. “Rufa knots, especially long-distance red knots, could be lost,” he said in a note to supporters. “We can’t stop bad winds or cold water, but we can expand the population of horseshoe crabs, so birds arriving in most of these conditions find an abundance of horseshoe crab eggs.”

The New York Times
June 05, 2021


Vaccine testing is changing. Why is this $13B lab still bleeding SC horseshoe crabs?

“When they present data, there is always a spin,” said Dr. Jessica Ponder, a toxicologist at Physicians Committee for Responsible Medicine, a nonprofit based in Washington, D.C. “They want to establish a paradigm where LAL is the gold standard purely on precedent, which is not scientific. The oldest method is not the best method in most of science.”

The State
February 11, 2021



How the Race for a COVID-19 Vaccine Jeopardizes East Coast Shorebirds.

“Until it does, pharmaceutical companies—including Pfizer and Moderna—will be reluctant to adopt rFC-based tests, which means COVID-19 vaccine development will require horseshoe crab blood. An antibody treatment developed by Eli Lilly and recently given emergency authorization by the FDA, however, is a different matter: Like anything else the company produces, it will be tested and brought to market using rFC.”

Audubon Magazine
November 2o, 2020


Horseshoe crab blood is key to making a COVID-19 vaccine—but the ecosystem may suffer.

“All pharmaceutical companies around the world rely on these crabs. When you think about it, your mind is boggled by the reliance that we have on this primitive creature,” says Barbara Brummer, state director for The Nature Conservancy in New Jersey.

National Geographic
July 2, 2020

Revive & Restore

An Interview with Ryan Phelan: Using Biotechnology to Revive Endangered Species and Restore Damaged Ecosystems

“The race to develop COVID-19 vaccines…highlights the need for making available to pharmaceutical companies a safe and scientifically proven LAL alternative with minimal regulatory hurdles.”

Wilson Sonsini Life Science Report
July 1, 2020

U.S. Pharmacopeia

Big Pharma’s U-Turn Threatens 450-Million-Year-Old Species On Front Line Of Coronavirus Defense

“in a widely unexpected development against the backdrop of the coronavirus pandemic, the US Pharmaceutical industry body (US Pharmacopeia) that recommends which tests should be used, rolled back recommendations on the use of the sustainable alternative – possibly setting back the adoption of the alternative by at least four years.”

June 28, 2020


Tests for Coronavirus Vaccine Need This Ingredient: Horseshoe Crabs

“It is crazy-making that we are going to rely on a wild animal extract during a global pandemic,” Ryan Phelan, the head of the nonprofit Revive and Restore, said before the recent decision.

The New York Times
June 03, 2020


Conservationists: COVID-19 could impact NJ’s horseshoe crab population

“Groups like the NJ Audubon estimate that 30% of horseshoe crabs do not survive once they are returned to the wild. Any more harvesting could further threaten the crab population, which is already struggling.”

News 12 New Jersey
June 25, 2020


The Race for a Coronavirus Vaccine Runs on Horseshoe Crab Blood

“…An estimated 50,000 crabs die during the annual blood harvest, and these ancient arthropods are also being threatened by pollution, overfishing (for use as eel bait) and habitat loss due to sea level rise.”
June 08, 2020


Pharma giants refuse to stop crab blood tests for new drugs despite dwindling population

“Although the alternative, which is derived from the chemical makeup of the real blood, but manufactured without any animal material has been increasingly used in medical research; use of horseshoe crabs, still, remains prevalent.”

Totally Vegan Buzz
June 05, 2020


Big Pharma Urged to Drop Crab-Blood Test for Possible COVID-19 Vaccine

“There may not be enough horseshoe crabs in the sea to cover the demand that you have for endotoxin tests for a billion doses of the vaccine,” said Chris Earl, a conservationist and former venture capitalist.”

June 01, 2020


Wildlife groups up pressure on Big Pharma to curb crab blood addiction

“Companies including Lonza and Charles River Laboratories are the biggest crab bleeders, supplying many of the 70 million annual endotoxin tests in a roughly $1 billion market.”

June 01, 2020


Drugs standards group nixes plan to kick pharma’s crab blood habit

“An industry battle has been brewing, as another testing giant, Lonza’s U.S.-based rival Charles River Laboratories, has criticized the synthetic option on safety grounds.”

May 30, 2020


Migration Numbers Plummet for Imperiled Shorebird on NJ’s Delaware Bayshore

“It was a snapshot of a dramatic decline in the number of knots that have stopped off on the bay beaches so far during this year’s migration, a change that has no precedent in the 24 years that Niles, a wildlife biologist, has been monitoring the annual visits of thousands of knots and other shorebirds.”

May 19, 2020



This Living Fossil May Have Saved Your Life

“The horseshoe crab is a living fossil that’s called Earth its home for almost half a billion years. And if you’ve ever had a vaccine, injection, or a medical implant, then you might not know that you’ve been relying on this prehistoric creature’s blood to save your life. Now, after decades of waiting, a new synthetic solution could change all of that.”

Bloomberg: New Economy
June 24, 2019

Red Knot Conservation:

The Shorebirds of Delaware Bay Are Going Hungry

“On their migrations north, famished birds stop to feast on eggs laid by horseshoe crabs. But the crabs were overfished, and conservationists say that some bird species may not recover.”

The New York Times
June 3, 2019



Horseshoe Crabs Are at Risk – So Endotoxin Tests Are, Too

“The horseshoe crab’s amebocytes, or blood cells, contain a clotting agent that forms in the presence of Gram-negative bacteria. This agent, which is used to detect endotoxin in pharmaceutical and medical device products, may become scarce if horseshoe crab populations continue to decline.”

GEN: Genetic Engineering & Biotechnology News
October 1, 2018


FDA Approves First Drug Tested for Endotoxins with rFC

Eli Lilly’s migraine-prevention drug, galcanezumab, is the first drug approved by the U.S. Food & Drug Administration to be used rFC as the release test for bacterial endotoxins. Thanks to the perseverance of consulting biologist Jay Bolden, Eli Lilly is in the process of transitioning 90 percent of its endotoxin tests from LAL to rFC.

September 27, 2018


Inside the Biomedical Revolution to Save Horseshoe Crabs and the Shorebirds That Need Them

“It’s taken Bolden, a birder, to persevere, and he’s collected enough data to convince his employer that it’s time to make the switch. If rFC is taken up by the rest of big pharma, it will be a groundbreaking change.”

Summer 2018


Alternative to horseshoe crab blood for medical testing may save species

“The Delaware Bayshore is “one of the top five places on the planet for shorebirds,” Stiles said. “This is our Serengeti.”

The Press of Atlantic City
May 12, 2018

The Last Days of the Blood Harvest

The Atlantic | Sarah Zhang | May 9, 2018

“Every year, more than 400,000 crabs are bled for the miraculous medical substance that flows through their bodies—now pharmaceutical companies are finally committing to an alternative that doesn’t harm animals,” writes Zhang. That synthetic alternative, Recombinant Factor C, provides a “way for modern medicine to make use of modern technology rather than the blood of an ancient animal.”