in n out burger
Flickr/@kevinv033

From the no-frills menu to the juicy burgers and secret sauce, what’s not to love about In-N-Out?

Apparently one thing, according to some vocal fans: The company is still using meat from animals that are fed antibiotics.

On Thursday, representatives from more than 30 consumer and environmental groups sent a letter to the California-based chain asking it to stop serving meat produced with the drugs.

Last year, a larger group of consumer organizations sent In-N-Out a similar letter. The company responded, stating it was “committed to beef that is not raised with antibiotics important to human medicine,” and promised to ask its suppliers to look for alternatives. They did not set down any specific dates for achieving those goals, however.

The newest letter asks the chain to set a timeline for using antibiotic-free meat.

”It’s time for In-N-Out Burger to stop dragging its feet and make good on its promise to require its meat suppliers to improve practices and end the misuse of antibiotics,” Kari Hamerschlag, deputy director of food and technology at the nonprofit organization Friends of the Earth, said in a press release.

Antibiotics
Getty Images/Joe Raedle

The practice of feeding antibiotics to farm animals has become routine. When first introduced, it was seen as a helpful tool to keep infections in livestock at bay. But the drugs started getting fed in excess to animals like…