Over the counter antiaging supplements taken by millions of Americans could interfere with cancer treatment, according to a new study. The products are commonly used to boost energy, support general wellness and lessen the side effects of chemotherapy.

Researchers at the Case Western Reserve University School of Medicine examined popular vitamin B3 derivatives, including nicotinamide mononucleotide, nicotinamide riboside and nicotinamide. These compounds are also known as NMN, NR and NAM.

The body uses the compounds to produce NAD+, a molecule that helps cells generate energy and repair damage. However, the researchers found that pancreatic cancer cells may use those additional resources to withstand chemotherapy.

The study was published in the journal Cancer Letters and focused specifically on pancreatic cancer. The disease has a 13% five year survival rate, according to the American Cancer Society.

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Although increasing NAD+ levels through dietary supplements may benefit cells that are not cancerous, the study suggests the effect could become harmful during active cancer treatment. Pancreatic cancer cells may exploit the additional resources to repair damage caused by chemotherapy and avoid cell death.

Researchers tested the supplements in laboratory settings and animal models. In those experiments, the supplements protected cancer cells against three common chemotherapy drugs.

As a result, tumors survived chemotherapy doses that typically would have been fatal to them, according to the findings. The results raised concerns about patients using NAD+ boosting products while receiving chemotherapy.

Study lead Jordan Winter is a professor at Case Western Reserve School of Medicine. He is also co leader of the developmental therapeutics program at the Case Comprehensive Cancer Center.

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Winter described the findings as potentially concerning for people with active cancer, particularly when NAD+ boosting supplements are used alongside chemotherapy. He also called the discovery a call to action for the medical community.

“This research is a critical reminder that ‘natural’ doesn’t always mean safe, especially in the complex biology of cancer treatment,” Winter added.

The researchers emphasized that the vitamin B3 derivatives are not considered dangerous for healthy people who use them for general wellness. The concern identified by the study applies to patients undergoing active cancer therapy.

Because additional NAD+ can provide energy to cells, pancreatic cancer cells may be better able to repair DNA damage caused by chemotherapy, the researchers found. That response could allow the cells to survive treatment that would otherwise destroy them.

In response to the findings, the research team recommended that oncology teams routinely screen patients for supplement use. The researchers also called for further studies examining how NAD+ precursors interact with cancer therapies.

Winter urged patients who are currently receiving treatment to consult their oncologists before taking any over the counter supplements. The warning reflects the study’s focus on interactions between supplement use and active chemotherapy.

However, the researchers also identified important limitations. The study relied on laboratory cell cultures and animal models, so its findings may not directly reflect how human patients process the supplements during treatment.

The research focused exclusively on pancreatic cancer. Therefore, the supplements may not have the same effect on chemotherapy for other forms of cancer or when used with different combinations of drugs.

The study also evaluated only short term cellular responses under controlled laboratory conditions. It did not involve human clinical trials, leaving the long term effects on cancer patients unclear.

The findings do not indicate that the supplements are inherently dangerous for healthy people using them for antiaging or wellness purposes. Instead, they suggest a possible risk when the products are taken during active chemotherapy for pancreatic cancer.