Online pharmacy Valisure has conducted additional research on Zantac and its ability to produce N-nitrosodimethylamine (NDMA). Findings appear in the January 29, 2021, issues of JAMA Network Open and MedRxiv, and they reveal that Valisure’s June 2019 detection of the carcinogen NDMA in Zantac and generic ranitidine samples was not an accident. According to Valisure’s new studies, ranitidine (the generic form of Zantac) can produce NDMA inside the human body under specific conditions.

Study 1: Simulated Human Stomach

Valisure researchers teamed up with New York’s Memorial Sloan Kettering Cancer Center scientists in this first study. The group created lab conditions that would simulate the digestive system in humans. They used nitrites, the natural chemicals found in fruits and vegetables (also used as food additives) and ranitidine in varying combinations, combining them with a simulated gastric fluid.

The simulated stomach showed that when nitrite concentrations were increased and added to 150 mg of ranitidine, NDMA formed in increasing amounts, as follows:

Sodium NitriteRanitidineNDMA
1 mmol/L150 mg947 ng
50 mmol/L150 mg320,000 ng

The results are especially alarming considering that the U.S. Food and Drug Administration’s (FDA) recommended daily limit of NDMA is only 96 ng.

Study 2: The Ranitidine-Cancer Link

The scientists continued their study of the effects of ranitidine intake by experimenting with varying levels of nitrite concentrations and ranging durations of time.

Results related to the nitrite concentrations matched those of the previous study. Furthermore, whereas the previous study limited observations to four hours, the second study extended this duration, and results indicated the continued formation of NDMA beyond four hours.

The second study also comprised data analysis of more than 10,000 cancer patients. Specifically, the scientists considered patients’ use of ranitidine. Their analysis revealed that ranitidine use was linked to greater odds of various cancers, including prostate, thyroid, breast, and bladder cancer. Interestingly, lower odds of colorectal cancer were associated with ranitidine use, according to the study.

Valisure’s David Light commented in a press release that the studies’ findings support previous research indicating the fundamental instability of ranitidine and that it is capable of forming NDMA in the human body and could be “carcinogenic and toxic to humans.”

The Continuing Aftermath

With the FDA’s April 1, 2020 request to recall all forms of ranitidine from the market, people who have taken Zantac or the generic ranitidine feel the weight of concern about developing cancer from this use.

In its news release about the recall, the FDA recommended that consumers and patients stop taking over-the-counter Zantac and/or ranitidine products, dispose of the unused products, and talk to their healthcare professionals about alternative treatments. The FDA further encouraged users to report adverse reactions to the agency using its MedWatch Adverse Event Reporting program.

Sara Stephens is a freelance writer who has developed a hefty portfolio of work across several industries, with a strong emphasis on law, technology, and marketing. Her work has appeared in the New York Times, as well as various technology and consumer publications, both print and online. Sara also works as a freelance book editor, having developed and edited manuscripts for bestselling and novice authors alike, and as a verbal strategist for a Miami branding consultancy.