Biotin Supplements Interfere with Cancer Lab Tests, Oncology Experts Warn
Oncology specialists are warning cancer patients against biotin supplementation, citing its capacity to distort critical laboratory test results including hormone panels used to monitor treatment and detect recurrence.
An oncodermatologist at The Ohio State University Comprehensive Cancer Center is warning against biotin use in cancer patients, claiming that it can cause inaccurate, misleading lab test results that can upend patients' treatment plans. Mounting concerns surround common biotin supplementation, with the American Academy of Dermatology highlighting the scarcity of evidence supporting its use for hair growth.
Biotin, also known as vitamin B7 or vitamin H, is a water-soluble B-complex vitamin that helps metabolize carbohydrates, fats and proteins into energy. It also supports the production of keratin, a structural protein essential for the strength and protection of hair, skin and nails. Cancer patients have increasingly turned to biotin to boost their hair growth and thickness, especially if they are undergoing chemotherapy.
"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," said Dr. Brittany Dulmage, associate director of dermatology at Ohio State's College of Medicine and director of the Oncodermatology Clinic. Biotin's capacity to skew essential laboratory results, particularly hormone panels, occurs by binding to test reagents. For individuals undergoing cancer therapy, these distorted blood work outcomes present a significant risk, potentially impacting oncological monitoring and critical treatment decisions.
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 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," Dulmage explained. "For reproductive hormones, including estrogen and testosterone, it may falsely elevate levels, resulting in delayed therapy."
Even if you don't have cancer, biotin supplements can mess with thyroid testing, at-home urine testing for pregnancy and cardiac troponin testing, used to diagnose a heart attack. If you don't want to give up biotin supplements, Dulmage advises stopping them 72 hours before blood work.
Research examining online cancer patient communities reveals a striking pattern: vitamins and supplements top the list for self-managing hair loss. More concerning, only a small fraction of this patient cohort consulted a dermatologist. This data underscores a critical gap in communicating potential treatment interactions when care relies solely on patients presenting in a clinical setting.
Dulmage recommends taking topical or low-dose minoxidil, sold under the brand name Rogaine, instead of biotin supplements, unless the patient is pregnant or breastfeeding. Special caps that cool the scalp to between 64 and 72 degrees Fahrenheit can also prevent or minimize hair loss by limiting the amount of chemotherapy medication reaching the hair follicle cells.
"More than half the patients who come to see me with a problem related to hair loss are on a supplement that they've started on their own after learning about it online, by word of mouth and sometimes even at the advice of their doctor," Dulmage said. She cautions against saw palmetto, found in hair, skin and nail supplements, which can indirectly increase estrogen levels, potentially affecting hormone-sensitive cancers such as breast cancer. Vitamin B12 taken before and during chemotherapy "has been shown to be statistically associated with poorer disease-free survival and overall survival, though the mechanism of this effect is unclear," Dulmage said. Similarly, iron supplementation before and during chemotherapy has been associated with a higher risk of breast cancer recurrence.
"My main advice to oncology patients with supplement use is to let your oncology team know what you are taking and what you hope to gain from a particular supplement," Dulmage said. "They can confirm if a particular supplement is acceptable and recommend alternative treatment approaches if necessary."