Biotin Supplements May Complicate Cancer Care, Research Shows

For many people living with cancer, hair loss can be one of the most visible and emotionally difficult side effects of treatment. In search of regrowth, some patients turn to biotin supplements, which are widely marketed for hair and nail health. However, emerging evidence suggests that these supplements may create unintended problems for people undergoing cancer care, including interference with critical blood tests used to guide treatment decisions, according to a news release from The Ohio State University Comprehensive Cancer Center.

According to experts, although biotin is often perceived as a harmless vitamin, taking it in supplement form may affect laboratory results for certain cancers. This interference can lead to inaccurate readings, delayed diagnoses or changes in care plans. As awareness grows, clinicians are encouraging patients to talk openly about supplement use and consider safer, evidence-based alternatives for managing hair loss.

“Many patients turn to biotin supplements because of their perceived safety. They are easy to obtain from the supplement aisle at a local drugstore; it seems like there is not a lot of risk associated with them,” Dr. Brittany Dulmage, an oncodermatologist at The Ohio State University Comprehensive Cancer Center, said in an interview with CURE.

How biotin supplements can affect cancer blood tests

Biotin, also known as vitamin B7, plays a role in normal metabolism and protein formation, including keratin production in hair and nails. However, true biotin deficiency is uncommon because the vitamin is readily obtained through everyday foods such as eggs, dairy products, meats, fruits and vegetables.

Problems arise because many modern laboratory tests rely on biotin-based chemical reactions to measure hormone and protein levels in the blood. When patients take high doses of biotin supplements, those tests may produce results that appear higher or lower than they actually are.

“Biotin does not change hormone levels in the body; it does not cause your body to produce more or less of a hormone. Instead, when blood is drawn, biotin can bind to some of the reagents (the chemicals added to the test tube) and interfere with the lab results. This can cause some readings to appear too high and others to appear too low,” Dulmage explained in the interview.

This interference may be especially concerning for patients with cancers that rely on hormone or tumor marker monitoring, including breast, prostate, thyroid and ovarian cancers. In these cases, inaccurate results could make it appear as though a cancer is stable, progressing, or responding to treatment when it is not.

As director of an oncodermatology clinic, Dulmage regularly treats patients experiencing hair, skin and nail changes related to chemotherapy, immunotherapy, and targeted therapies. Her clinical experience, combined with growing research, prompted her to help author guidance published in JCO Oncology Practice calling for more proactive conversations between oncologists and patients about hair loss and supplement use.

Why hair loss is so distressing for patients

Hair loss can feel deeply personal, affecting self-image, confidence and emotional well-being. For some patients, it becomes one of the most anticipated and feared aspects of cancer treatment.

“Your hair is very much a part of you. One of the first things you ask is ‘Am I going to lose my hair?’ It’s such an important thing for people – not everybody looks good with no hair,” breast cancer survivor Anna Malagoli said in the news release.

After completing treatment and entering remission, Malagoli hoped to restore her long, curly hair and turned to biotin supplements based on online recommendations.

“The amount of information on the Internet can lead you in different directions. I was taking so much biotin it’s not even funny,” she said. “Nobody mentioned one word that biotin vitamins or minerals or supplements could interfere with your treatment or your testing.”

How researchers identified the risks of biotin

Clinical observations raised concerns when patients taking biotin supplements showed blood test results that did not align with symptoms or imaging findings. Further investigation revealed that biotin could disrupt assays measuring prostate-specific antigen (PSA), thyroid-stimulating hormone (TSH), estrogen, testosterone and cardiac markers such as troponin.

“Even if biotin does not alter treatment decisions, it has the potential to lead to additional unnecessary tests or imaging. If a patient were to receive falsely incorrect lab values, they may need to undergo additional unnecessary labs or imaging to further work up those false results,” Dulmage explained to CURE.

Patients undergoing active treatment, survivors in long-term surveillance and individuals with hormone-driven cancers may be particularly vulnerable to misleading lab results. Because blood work is often used to guide decisions such as treatment changes or imaging schedules, even small inaccuracies can have meaningful consequences.

Malagoli later realized her own lab fluctuations may have been linked to supplement use.

“My lab results were inconsistent. They just didn’t balance out with what I was feeling so that was a red flag. I think it had to do with the supplements I was taking,” she said.

Safer options for managing cancer-related hair loss

For patients who wish to continue biotin supplements, Dulmage recommends stopping them at least 72 hours before scheduled blood tests. However, she cautions that not all lab work is planned, particularly in urgent situations.

“This is why I recommend to patients — think about not taking it at all, especially since very few people are biotin deficient,” she said in the news release.

Instead, she points patients toward FDA-approved topical minoxidil, which has demonstrated safety and effectiveness for hair regrowth in many individuals.

“If you have been trying minoxidil for several months and not seeing any improvement or want to know about other options, see a dermatologist. There are many other types of treatments that may be an option,” she continued.

Malagoli, who has tried both approaches, found minoxidil more helpful.

“I don’t know if my body just doesn’t assimilate the supplements as well, but minoxidil is definitely more effective long-term,” she said. “I would say it’s super important to listen to your doctors and not just do your thing.”

References

1. “Cancer Patients Warned Popular Supplement May Interfere with Treatment,” by The Ohio State University Comprehensive Cancer Center. News release; Jan. 2026.
2. “Biotin Supplements for Hair and Nail Regrowth: A Caution for Oncologists,” by Layna Mager, et al. JCO Oncology Practice.
3. Biotin, Lab Interference and Safer Options for Cancer-Related Hair Loss, by Ryan Scott. CURE; Jan. 30, 2026. https://www.curetoday.com/view/biotin-lab-interference-and-safer-options-for-cancer-related-hair-loss

Editor's note: This article is for informational purposes only and is not a substitute for professional medical advice, as your own experience will be unique. Use this article to guide discussions with your oncologist. Content was generated with AI and reviewed by a human editor.

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