Doctors are trying to come up with anything that could help treat COVID-19. The latest treatment that is showing promise is a medication normally used for lice.

It's called ivermectin, and it is an antiparasitic drug, ABC News reported.

Testing of ivermectin is still in the early phases with only two preliminary studies completed.

But those two studies are giving experts "cautious optimism," ABC News reported.

Ivermectin was first dispensed in the 1970s and 1980s for treating nematodes in cattle. The pill form was then used to treat river blindness in humans. But now it’s used as a topical medicine for head lice.

It is so common that it is on the World Health Organization’s list of essential medicines.

In testing in Australia, single doses removed all RNA of COVID-19 in 48 hours in a controlled test tube environment, researchers told ABC News.

The way it works, according to researchers, is that ivermectin blocks the RNA of the virus from entering a healthy cell, slowing replication. By not replicating, the virus gives the person’s immune system time to fight it.

The results of the study were published in the Antiviral Research journal.

Keep in mind, though, the tests were done on a cellular level in test tubes. The next step is to test on humans and know the correct dosage.

Another study at the University of Utah showed that patients on ventilators with lung injuries could benefit from the drug.

The Food and Drug Administration has issued a warning that while the treatment is being tested, people should not take any form of ivermectin unless prescribed by a licensed health care provider.

The FDA said, "People should never take animal drugs, as the FDA has only evaluated their safety and effectiveness in the particular animal species for which they are labeled. These animal drugs can cause serious harm in people."

The FDA also said there is no emergency use authorization for ivermectin in the U.S.