Federal health officials have tied it to a nationwide outbreak of salmonella.
The C-D-C believes 28 salmonella cases in 20 states are due to kratom.
It's an herbal supplement some use as pain medication.
11 people have been hospitalized due to the contamination.
Kratom is a plant that's crushed and made into pills, powders, or tea.
Two of the people who became sick are in Pennsylvania.
The C-D-C thinks more people may have been affected but haven't reported it.
Earlier this month, the F-D-A warned against using kratom AT ALL, saying it's dangerous and has been linked to 44 deaths.
Read the CDC's full news release on the salmonella outbreak.