Pfizer is voluntarily recalling all lots of Chantix 0.5 mg and 1 mg tablets.
The Food and Drug Administration says the pills have the presence of Nitrosamine at or above its acceptable intake limit.
“Long-term ingestion of N-nitroso-varenicline may be associated with a theoretical potential increased cancer risk in humans, but there is no immediate risk to patients taking this medication,” the FDA said in a statement on its website.
Chantix is a treatment to help people quit smoking.
The FDA says patients can continue to take their current medication until their provider offers a replacement.
“The health benefits of stopping smoking outweigh the cancer risk from the nitrosamine impurity in varenicline,” the FDA said.