[7/02/2021] FDA is alerting patients and health care professionals to Pfizer’s voluntary recall of nine lots of the smoking cessation drug, varenicline (brand name Chantix), to the warehouse level. The company is recalling varenicline because it may contain levels of a nitrosamine impurity, called N-nitroso-varenicline, above FDA’s acceptable intake limit. N-nitroso-varenicline may be associated with a potential increased cancer risk in humans, but there is no immediate risk to patients taking this medication. An increased cancer risk would be associated with long-term use, and the health benefits of stopping smoking outweigh the cancer risk from the nitrosamine impurity in varenicline.

Recalled lots:

Lot number Expiration date



















N-Nitroso-varenicline belongs to the nitrosamine class of compounds, some of which are classified as probable or possible human carcinogens (substances that could cause cancer), based on laboratory tests such as rodent carcinogenicity studies. Although there are no data available to directly evaluate the carcinogenic potential of N-nitroso-varenicline, information available on closely related nitrosamine compounds was used to calculate lifetime exposure limits for N-nitroso-varenicline.

Pfizer is recalling the varenicline lots currently stored in warehouses. FDA recommended Pfizer revise its recall to the consumer level in order to take into account the product currently on the market, but the company has not yet done so.

In addition to the voluntary recall, Pfizer is holding release of varenicline to the U.S. market until it can confirm N-nitroso-varenicline levels below what the company considers to be acceptable.

What patients should know:

  • Continue taking your current medicine until your doctor or pharmacist gives you a replacement or a different treatment option.
  • Contact your health care professional if you are taking this medication and have questions about your health.

What health care professionals should know:

  • FDA has determined the recalled varenicline poses an unnecessary risk to patients. Therefore, FDA recommends health care professionals consider other available treatment options for the patient’s medical condition.
  • If you have varenicline samples from this company, quarantine them, and do not provide them to patients.
  • Contact Pfizer directly if you have questions regarding product return or disposal.

FDA is actively considering options to help mitigate a shortage of varenicline in the U.S. including working to identify an alternate supplier. The agency is continuing to investigate the presence of N-nitroso-varenicline in varenicline products and will provide more information as it becomes available.

We know impurities in medicines are of great concern to patients and consumers who rely on safe and effective medicines approved by FDA, and we are working with manufacturers and global regulators to provide clear and actionable information. In September 2020, FDA published a guidance for industry entitled “Control of N-Nitrosamine Impurities in Human Drugs.” This guidance recommends steps manufacturers of active pharmaceutical ingredients (APIs) and drug products should take to detect and prevent objectionable levels of nitrosamine impurities in pharmaceutical products.

Today, we have better testing methods than ever before, and we have a better understanding of what to look for in products’ chemical structure and manufacturing processes that may increase the risk of forming low levels of impurities. Improved technology enables us to detect even trace amounts of impurities in drug products and may be the reason why more products have been recently found to have detectable levels of nitrosamines.

FDA continues its ongoing review, surveillance, compliance and pharmaceutical quality efforts across every product area and will continue to work with drug manufacturers to ensure safe, effective and high-quality drugs for the American public.

Patients and health care professionals should report any adverse reactions with varenicline to FDA’s MedWatch program to help the agency better understand the scope of the problem: