A drug typically used to treat parasites in livestock is harder to come by in some places, and some suppliers say it’s due to misinformation about it’s effectiveness in treating COVID-19.

Clinical trials on the use of ivermectin to treat coronavirus are underway in the U.S. but so far it hasn’t proven effective. The drug is approved for use in humans to treat parasites and lice.

Despite that, some are seeking out the veterinary form of ivermectin, which isn’t intended for human consumption and has left some shelves bare at feed stores. That’s also driving up the cost of the drug for some.

Some who work with livestock in Maine say they’re seeing the effects of increased demand. Tessa Flannery, who raises alpacas in Aroostook County, tells the Bangor Daily News her primary supplier of the drug was out of stock, but she was able to purchase some online for double the amount she paid last year.

A shop owner in Hebron who uses the paste form of the drug to treat her horses says she’s had trouble finding her usual brands, but was able to get some on backorder.

However, other shop owners and those who treat livestock said they haven’t seen a noticeable difference in pricing or supply.

Some poison control centers in states including Kentucky and Minnesota have reported an uptick in calls from residents who’ve used the veterinary form of the drug to try to treat coronavirus.