A carcinogen is a substance or material capable of causing cancer.
Lab tests recently discovered n-nitrosodimethylamine (NDMA) in Zantac heartburn pills. It was also found in ranitidine drugs, the generic form of Zantac. NDMA is a probable human carcinogen.
Drugmakers issued voluntary recalls for the contaminated pills. But many consumers want to understand the cancer risk associated with recalled Zantac.
Does Zantac Cause Cancer?
Zantac alone does not pose any significant risk of cancer. However, contaminated Zantac does pose a cancer risk.
The U.S. Food and Drug Administration (FDA) says contaminated Zantac and common foods like smoked or grilled meats contain similar amounts of NDMA. Smoked and grilled meats increase the risk of certain cancers by 70% – 300% according to scientific studies.
The Link Between Zantac and Cancer
NDMA was first discovered in Zantac by Valisure, an independent online pharmacy. This discovery triggered investigations into the extent and causes of NDMA in Zantac.
Valisure testing identified two possible sources of NDMA in Zantac:
- Contamination – The manufacturing process could leave NDMA contamination in the final Zantac product.
- Conversion – Zantac could break down in the human stomach. Those smaller molecules can collide and create NDMA.
Valisure highlighted both NDMA sources when they notified the FDA of their findings. The company reached out to the FDA using a citizen petition.
The petition encouraged scrutiny of the conversion issue, as it poses an unknown risk. If Zantac can form NDMA as it breaks down in the body, exposure levels may be higher than the current estimates. This may be true for uncontaminated Zantac as well.
What is NDMA?
NDMA is a combustible molecule capable of producing toxic fumes. NDMA is not produced in the U.S., except for scientific research. It is most often used to cause cancer in laboratory animals. In the past, it was used for manufacturing and in the production of rocket fuel.
NDMA is classified as a probable human carcinogen by two regulatory agencies:
- The U.S. Environmental Protection Agency (EPA)
- The International Agency for Research on Cancer (IARC)
NDMA has not been conclusively studied in humans. Yet, regulators classify NDMA as a probable human carcinogen based upon its behavior in animals.
Scientific Study: Zantac Leads to NDMA in Urine
In 2016, a scientific study was published looking at the link between NDMA production and ranitidine. The researchers collected urine samples before and after the study patients took Zantac.
The researchers found that after taking Zantac, the levels of NDMA found in patients’ urine samples increased several hundredfolds. The amount of NDMA found was 496x the FDA’s acceptable daily limit of 96 nanograms.
The study included only ten patients. Further research is necessary to determine the true risk. However, the study authors suggest increased scrutiny of NDMA levels after taking any form of Zantac.
The Real Cancer Risk of NDMA Contamination
The FDA has yet to release an official estimate of the potential cancer risk posed by NDMA-contaminated Zantac. However, the agency is currently comparing the NDMA levels found in Zantac to those found in smoked meats.
Smoked meats are associated with a 77% increased risk of breast cancer for all women. In post-menopausal women, smoked meats are associated with a 306% increased risk of breast cancer. Smoked meats are also linked to an increased risk of gastrointestinal cancer.
The FDA did estimate the cancer risk for NDMA contaminated valsartan:
“FDA scientists estimate that if 8,000 people took the highest valsartan dose (320 mg) from the recalled batches daily for the full four years, there may be one additional case of cancer over the lifetimes of these 8,000 people. This assessment led to FDA’s decision to have these batches recalled.”
The FDA has not announced a global recall on Zantac or other ranitidine products. The agency maintains ranitidine does not form NDMA in the “normal human stomach.” The FDA does admit further investigation of NDMA formation in the body is necessary. Yet, no concrete plans to study or research the topic have been announced.
The FDA issued a list of safe alternatives for patients taking contaminated Zantac. You can find this list on our Zantac product page here.
Cancers Associated with NDMA
Scientific studies have found evidence that NDMA may increase the risk of the following cancers in humans:
- Bladder cancer
- Stomach cancer (Gastric Cancer)
- Esophageal cancer
- Cancer of the Nasopharynx
- Liver cancer
- Colorectal cancer
- Uterine cancer