Health Canada has approved early clinical trials of dandelion extract to see if it can be used to kill cancer.

The approval is for a phase one — or toxicology — trial. It will determine whether the body can tolerate the dandelion extract and, if it can, how much of the extract the human body can tolerate. 

Phase one trials do not reveal whether the substance being tested has a medicinal effect.

"The goal of the trial is not to see response it’s to set the right dose," said Dr. Caroline Hamm, who submitted the application for the trial in June.

Thirty patients will participate in the 10-month trial in 10 groups of three.

"When we start seeing serious side effects we cut back [the dose]," Hamm said.

Hamm said dandelion extract can cause liver problems and an upset stomach.

According to researchers, earlier test results showed that dandelion tea containing dandelion root extract killed cancer cells in a lab.

Hamm previously told CBC News dandelion root extract is unique and one of the only things found to help with chronic myelomonocytic leukemia, a type of cancer that starts in blood-forming cells of the bone marrow and involves the blood.

"There’s something there and that’s the key," Hamm said. "But the important message is that this is really, really early days. It’s important to chase it down but do it in the proper scientific fashion."

Hamm said the has been "worldwide interest from cancer patients" when it comes to the dandelion extract research being conducted at a Windsor, Ont., clinic.

Hamm said it’s important to be "realistic" about the research. She said it can take decades for new treatments to go from the phase one trial to becoming approved and effective.

"It’s still a maybe," Hamm said. "We still don’t know."