Biotin Supplements Can Interfere with Cancer Treatment, Experts Warn

Oncodermatologist cautions that high doses of the popular hair growth supplement can skew lab test results, potentially affecting cancer diagnosis and care.

Published on Feb. 21, 2026

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An oncodermatologist at The Ohio State University Comprehensive Cancer Center is warning cancer patients against using biotin supplements, as they can cause inaccurate and misleading lab test results that could disrupt treatment plans. Biotin, also known as vitamin B7 or vitamin H, is a popular supplement taken to boost hair growth, but it can interfere with the way certain hormones and other substances are measured in blood work, potentially masking cancer recurrence or affecting the timing of therapies.

Why it matters

Many cancer patients turn to biotin supplements to address hair loss caused by chemotherapy, but this practice can have unintended consequences. Inaccurate lab results could lead to delayed or inappropriate treatment, putting patients' health at risk. This issue highlights the importance of cancer patients consulting their oncology team before taking any supplements, to ensure they don't interfere with their care.

The details

Biotin, especially in high doses, can significantly interfere with hormone and cardiac lab tests, potentially affecting the treatment of thyroid, ovarian, breast and prostate cancers. For some hormones, like prostate-specific antigen (PSA) and thyroid-stimulating hormone (TSH), biotin may falsely suppress or lower the levels, potentially masking cancer recurrence. For reproductive hormones like estrogen and testosterone, biotin may falsely elevate the levels, resulting in delayed therapy.

  • Biotin supplements should be stopped 72 hours before any scheduled blood work.

The players

Dr. Brittany Dulmage

An oncodermatologist and associate director of dermatology at The Ohio State University Comprehensive Cancer Center's College of Medicine, as well as the director of the Oncodermatology Clinic.

The Ohio State University Comprehensive Cancer Center

A cancer treatment and research center located in Columbus, Ohio.

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What they’re saying

“Biotin does not actually change the levels of hormones in the body, but it interferes with the way those levels could be checked when blood work is done.”

— Dr. Brittany Dulmage, Associate Director of Dermatology, The Ohio State University Comprehensive Cancer Center

“For some of the hormones, such as prostate-specific antigen, PSA, or thyroid-stimulating hormone, TSH, it may falsely suppress or lower those levels, potentially masking cancer recurrence in cancer survivors.”

— Dr. Brittany Dulmage, Associate Director of Dermatology, The Ohio State University Comprehensive Cancer Center

“For reproductive hormones, including estrogen and testosterone, it may falsely elevate levels, resulting in delayed therapy.”

— Dr. Brittany Dulmage, Associate Director of Dermatology, The Ohio State University Comprehensive Cancer Center

What’s next

Patients taking biotin supplements should stop them 72 hours before any scheduled blood work to avoid inaccurate test results.

The takeaway

Cancer patients should consult their oncology team before taking any supplements, including biotin, to ensure they do not interfere with their treatment plan and lab testing. Relying on unregulated supplements without medical guidance can have serious consequences for cancer patients.