Health Conditions A-Z Endocrine Conditions Type 2 Diabetes Metformin Recall: NDMA Contamination in Blood Sugar Medication In January 2022, the Food and Drug Administration recalled metformin, which controls blood sugar in people with type 2 diabetes. By Korin Miller Updated on January 25, 2023 Medically reviewed by Kristie Reed, PharmD Medically reviewed by Kristie Reed, PharmD Kristie Reed, PharmD, oversees emergency, general medical, surgical, psychiatric care, and oncology medication as the pharmacy director of a community hospital. Dr. Reed specializes in IV medications. learn more Share Tweet Pin Email In January 2022, the Food and Drug Administration announced a voluntary recall of metformin. People with type 2 diabetes use metformin to control their blood sugar alongside a healthy diet and exercise. Concerns over higher-than-acceptable levels of the probable cancer-causing contaminant N-nitrosodimethylamine (NDMA) prompted the recall. The recall came when Nostrum Laboratories, Inc. announced that it voluntarily recalled one lot of its metformin HCl extended-release tablets. The affected product was packaged in 100-tablet bottles, has the NDC of 29033-056-01, a lot number of MET200501, and an expiration date of July 2022. As of January 2023, Nostrum Laboratories, Inc. hasn't received any reports of adverse events related to the recall. The January 2022 incident wasn't the first time metformin has been recalled over NDMA concerns. In fact, per the Food and Drug Administration, metformin recalls span back to early 2020. If you use metformin or have a loved one taking the medication, it's more than understandable to be concerned. Here's what you need to know about NDMA, how it ends up in metformin, and what your next steps should be if there's another recall. P&G Recalls Certain Hair Products From Brands Like Pantene, Aussie After Cancer-Causing Chemical Detected What Is NDMA? NDMA is a semi-volatile organic chemical that forms in industrial and natural processes. Per the Environmental Protection Agency, NDMA is a yellow liquid with no distinct odor and is a member of N-nitrosamines, a family of potent carcinogens. Carcinogens are cancer-causing substances. The Environmental Protection Agency lists NDMA as a "priority pollutant." In other words, NDMA is a pollutant that the agency regulates and can practically use. But exposure to high levels of NDMA can cause symptoms like: HeadacheFeverNausea and vomitingJaundice, or yellowing of the skinStomach crampsEnlarged liverReduced function of the liver, kidneys, and lungsDizziness Coca-Cola Recalled Some Minute Maid Juices After Potential Metal Contamination—Here Are the Affected Products How Can NDMA End Up in Medication? Manufacturers have previously used NDMA to produce rocket fuel, antioxidants, and softeners for objects like nitrile rubber. But as of 2023, people only use NDMA for research purposes. Still, NDMA can be an accidental byproduct of the chlorination of wastewater at treatment plants. Also, industrial sources may unintentionally produce and release NDMA as a byproduct of chemical reactions. For example, alkylamines with nitrogen oxides, nitrous acid, or nitrite salts may produce NDMA. So, when it comes to metformin, NDMA can be a result of the manufacturing process, Karl Nadolsky, DO, an endocrinologist at Spectrum Health Medical Group, told Health. Or NDMA may be a contaminant that ends up in the medication. Also, the medication's structure may affect the byproducts and produce NDMA, Jamie Alan, PhD, an associate professor of pharmacology and toxicology at Michigan State University, told Health. However, "in the case of metformin, this is probably a contaminant," noted Alan. According to the Food and Drug Administration, levels of nitrosamine impurities should not be higher than 96 nanograms per day. Recalls over nitrosamine impurities exceeding that limit occurred before the January 2022 incident. For example, on December 28, 2021, Viona Pharmaceuticals, Inc. issued a voluntary recall of 33 lots of its metformin HCl extended-release tablets after detecting NDMA. So, why do those recalls happen so many times? Well, many companies buy the raw powder to make those medications from the same supplier, Bruce Ruck, PharmD, managing director of the NJ Poison Control Center at Rutgers New Jersey Medical School, told Health. "Even though my tablet may be from company A and your tablet may be from company B, the raw powder is probably from the same company way up on the chain," explained Ruck. "If that powder is contaminated, it will end up in multiple brands." Benzene, a Carcinogen, Found in Batches of Deodorants: Here's What You Need to Know What Should You Do if You’re Taking Recalled Metformin? Before the January 2022 recall, the Food and Drug Administration advised people taking metformin to continue taking it until a healthcare provider replaced their prescription. Or a healthcare provider could provide a different treatment option. Per the Food and Drug Administration, if people with type 2 diabetes stop taking metformin, they may have dangerous side effects. So, if a recall affects your prescription, consulting a healthcare provider before making any changes is important. Also, as of January 2023, the agency has not found NDMA in immediate-release tablets. And those tablets are some of the most commonly prescribed types of metformin. Taking a medication contaminated with a potentially cancer-causing ingredient may seem odd. Still, panicking over any recalls may not be necessary, urged Dr. Nadolsky. Instead, reach out to a healthcare provider or pharmacist as soon as possible to ask about alternatives, recommended Dr. Nadolsky. "This is weighing the benefits versus the risk," said Alan. "If the patient's blood sugar gets too high, this can be life-threatening." Symptoms of high blood sugar, or hyperglycemia, include: Excessive thirstDry mouthBlurry visionDry skinFatigueFrequent urination In the case of NDMA, "you have to be exposed to a certain amount over your lifetime," added Alan. "Meanwhile, high blood sugars can be extremely dangerous in the short term." A Quick Review Learning that a common medication contains a possible carcinogen can be scary. Still, if you have type 2 diabetes, stopping metformin may cause adverse side effects. So, if a recall affects you or a loved one, reach out to a healthcare provider or pharmacist. They can advise you on what to do and guide you on the next steps. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit Sources Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Food and Drug Administration. Nostrum Laboratories, Inc. expands voluntary nationwide recall of metformin HCl extended release tablets, USP 750 mg, due to N-nitrosodimethylamine (NDMA) content above the acceptable daily intake (ADI) limit. Environmental Protection Agency. Technical fact sheet — N-nitroso-dimethylamine (NDMA). Environmental Protection Agency. Toxic and priority pollutants under the Clean Water Act. Food and Drug Administration. Liquid chromatography-electrospray ionization-high resolution mass spectrometry (LC-ESI-HRMS) method for the determination of nitrosamine impurities in metformin drug substance and drug product. Food and Drug Administration. Viona Pharmaceuticals Inc., issues voluntary nationwide recall of metformin HCl extended-release tablets, USP 750 mg, due to the detection of N-nitrosodimethylamine (NDMA) impurity. Food and Drug Administration. FDA updates and press announcements on NDMA in metformin. National Library of Medicine. High blood sugar - self-care.