Using herbs to end a pregnancy can be harmful. Overconsumption of pennyroyal and mugwort, for example, can cause liver failure, according to Ryan Marino, the medical director of toxicology and addiction at the University Hospitals in Cleveland, Ohio.

Marino said he has seen several extreme cases of herbal poisoning among his patients, including some who suffered seizures. Pennyroyal is especially dangerous, he said.

“Even in cases where people don’t get symptomatic, or don’t end up hospitalized, it’s associated with long-term cancer risk,” Marino said. “It’s a known human carcinogen, and every time those molecules are in your body, they’re doing something bad there.”

Marino said it is difficult to find data on the prevalence of herbal abortion attempts. Unless a woman discloses to a doctor that she has taken a specific herb, it’s hard to link particular symptoms to its consumption.