Hair loss is one of the most devastating side effects of cancer treatment, and many patients are looking for ways to get their hair back. One option that’s gaining popularity is biotin, a vitamin commonly recommended for strengthening hair and nails. But experts say the benefits are unclear and the risks may be overlooked.
There is little scientific evidence that oral biotin helps hair and nail growth in people undergoing or recovering from cancer treatment. Of further concern, says Brittany Dalmage, M.D., a dermatologist at The Ohio State University Comprehensive Cancer Center (Arthur G. James Cancer Hospital and Richard J. Solove Research Institute), it could interfere with medical tests.
Biotin, also known as vitamin B7, helps the body produce proteins such as keratin, which supports hair, skin, and nails. However, true biotin deficiency is rare because biotin is widely found in foods such as fruits, vegetables, meat, eggs, and dairy products.
“People have a misconception that biotin supplements are harmless and there is no reason not to take them. The reality is that supplements can cause inaccurate test results, resulting in delays or changes in a patient’s treatment plan,” she said.
Dalmage is also associate director of dermatology at The Ohio State University School of Medicine, where he leads the Oncodermatology Clinic, where patients are treated for hair, skin and nail side effects caused by treatments such as chemotherapy, immunotherapy and targeted therapies.
“More than half of the patients who come to me with hair loss issues learn about supplements online, through word of mouth, or sometimes on the advice of their doctor, and start taking them themselves,” she said.
To highlight these concerns, Dulmage wrote the following paper: JCO Oncology Clinic Oncologists are asked to openly discuss hair loss with patients and explain how biotin may affect test results.
How biotin skews cancer test results
Biotin can interfere with certain blood tests used to monitor cancers such as prostate, thyroid, ovarian, and breast cancer. Some of these tests rely on chemical reactions involving biotin, so taking supplements can make your results appear higher or lower than they actually are.
“Biotin doesn’t actually change hormone levels in the body, but it does interfere with the way hormone levels are checked during blood tests,” she says. “For some hormones, such as PSA, the prostate-specific antigen, and TSH, the thyroid-stimulating hormone, their levels can be falsely suppressed or lowered, potentially masking cancer recurrence in cancer survivors. For reproductive hormones, such as estrogen and testosterone, their levels can be falsely raised, which can delay treatment.”
Patient experiences and test results with biotin
Like many cancer patients, Anna Maragoli of Columbus was worried about losing her hair during breast cancer treatment.
“Your hair is a part of you. One of the first things to ask is, ‘Am I going to lose my hair?’ That’s something that’s very important to people, not everyone looks beautiful without hair,” she said.
After her cancer went into remission, she wanted her long curly hair back, so she read about biotin supplements online and started taking them.
“The amount of information on the internet can lead you in different directions. I was taking so much biotin that it wasn’t even funny,” she said. “At no time did anyone mention that biotin vitamins, minerals, and supplements could interfere with treatment or testing.”
Inconsistent test results raise concerns
Mr. Maragoli first became aware of this problem when he visited Mr. Dalmage. In retrospect, she said, that explanation matched her experience.
“The test results were inconsistent. They just weren’t in balance with what I was feeling, and that was a red flag. I think it had something to do with the supplements I was taking,” she said.
For patients who choose to continue using biotin, Dr. Dalmage advises discontinuing it at least 72 hours before a scheduled blood test.
“The challenge is that not all blood tests are scheduled, so you might not get biotin. Biotin can also affect your levels of troponin, which is a marker of whether you’re having a heart attack,” she says. “Of course you don’t want to have a heart attack, so you can’t take biotin before testing your troponin levels. This is why I recommend that my patients consider not taking biotin at all, especially since so few people are biotin deficient.”
Safer options for hair loss during cancer treatment
Dalmage suggests using minoxidil instead of biotin to combat hair loss. This treatment is FDA-approved, widely available over-the-counter, and comes in topical dosage forms such as lotions and foams. Although considered safe and effective for most people, it is not recommended during pregnancy or breastfeeding.
“If you try minoxidil for a few months and don’t see any improvement, or if you want to know about other options, talk to your dermatologist. There are many other types of treatments that may be options,” she said.
Maragoli tried both approaches and found that minoxidil worked better for him.
“I don’t know if my body just doesn’t absorb the supplement, but minoxidil is definitely more effective in the long run,” she says. “I think it’s really important to listen to your doctor and not just do your own thing.”

