Nobody mentioned biotin could interfere with your treatment or testing
In the quiet space between treatment and recovery, cancer patients reaching for biotin supplements to reclaim their hair may be unknowingly obscuring the very signals their doctors depend on to keep them safe. An Ohio State oncodermatologist has found that more than half of her patients with hair loss are self-medicating with biotin — a supplement that distorts the chemical reactions behind critical cancer monitoring tests, potentially masking recurrence or triggering false alarms. The danger lies not in what biotin does to the body, but in what it does to our ability to read it.
- Cancer patients desperate to recover their hair are turning to biotin in large numbers, often without any warning from their care teams about the risks hiding inside that seemingly harmless vitamin.
- Biotin quietly corrupts the lab tests oncologists rely on most — suppressing PSA readings in prostate cancer survivors, distorting TSH levels in thyroid patients, and falsely elevating hormones in breast and ovarian cancer survivors.
- One Columbus patient discovered her inconsistent lab results were likely caused by the biotin she had been taking in high doses, a connection no one had warned her about until she saw a specialist.
- The interference extends beyond cancer monitoring — biotin can also skew troponin levels used to detect heart attacks, meaning there is no safe window to simply pause the supplement before an emergency test.
- Minoxidil, FDA-approved and available over the counter, offers a clinically effective alternative for cancer-related hair loss without compromising the integrity of critical diagnostic results.
Cancer patients enduring chemotherapy's most visible toll — hair loss — are increasingly reaching for biotin supplements, drawn by widespread marketing and online research promising stronger hair and nails. But an oncodermatologist at Ohio State's comprehensive cancer center is raising an urgent warning: biotin may not be regrowing hair so much as hiding cancer's return.
Brittany Dulmage has seen the pattern repeatedly in her clinic. More than half of the patients who come to her with hair loss are already taking biotin they started on their own, sometimes even on a doctor's casual recommendation. What most don't know is that biotin disrupts the chemical reactions labs use to measure cancer markers — without actually changing what's happening in the body. PSA readings in prostate cancer survivors can drop artificially. TSH levels in thyroid cancer patients can be suppressed. Hormone levels in breast and ovarian cancer survivors can appear falsely elevated. The result is a test that lies, and a doctor who can't see what's truly coming.
Anna Malagoli of Columbus experienced this firsthand. After her breast cancer went into remission, she began taking high doses of biotin she'd researched online, determined to restore her curly hair. No one told her it could interfere with her monitoring. It wasn't until she met with Dulmage that she connected her puzzling, inconsistent lab results to the supplement she'd been taking. "Nobody mentioned one word," she said.
Dulmage, who published her findings in JCO Oncology Practice, is calling on oncologists to speak openly with patients about these risks. True biotin deficiency is vanishingly rare — the vitamin is plentiful in ordinary foods — making supplementation largely unnecessary and potentially dangerous. For patients seeking real relief from hair loss, she points to minoxidil: FDA-approved, available without a prescription, and effective without compromising the tests that could save a life. Malagoli tried both and found minoxidil worked better. Her advice now is simple — listen to your doctors before doing your own thing, because the stakes turn out to be far higher than a bottle of vitamins suggests.
Cancer patients dealing with chemotherapy's cruelest side effect—hair loss—are increasingly turning to biotin supplements, hoping to restore what their treatment has taken. The vitamin, marketed widely for its promise to strengthen hair and nails, seems like a harmless choice. But oncologists are now warning that this popular supplement may be doing something far more dangerous than failing to regrow hair: it may be hiding signs that cancer has returned.
Brittany Dulmage, an oncodermatologist at Ohio State's comprehensive cancer center, has watched this pattern unfold in her clinic. More than half of the cancer patients who come to her with hair loss are already taking biotin supplements they've started on their own—discovered through internet searches, conversations with friends, or sometimes even recommended by their own doctors. The problem is that biotin doesn't just sit harmlessly in the body. It interferes with the blood tests that oncologists rely on to monitor whether a patient's cancer is truly gone.
The interference is subtle but consequential. Biotin doesn't actually change the levels of cancer markers in the body, but it disrupts the chemical reactions that labs use to measure them. For prostate cancer survivors, biotin can artificially lower PSA readings—the very test designed to catch recurrence early. For thyroid cancer patients, it suppresses TSH levels in the same way. For breast and ovarian cancer survivors, it can falsely elevate hormone levels, potentially delaying the start of necessary therapy. A patient taking biotin might receive lab results that look reassuring when they shouldn't, or alarming when they're actually fine. The test becomes unreliable, and the doctor's ability to catch a returning cancer is compromised.
Anna Malagoli of Columbus learned this the hard way. After her breast cancer went into remission, she was determined to regain her long curly hair. She found information online about biotin and began taking it—a lot of it. "The amount of information on the Internet can lead you in different directions," she said. "Nobody mentioned one word that biotin vitamins or minerals or supplements could interfere with your treatment or your testing." It wasn't until she sat down with Dulmage that she discovered the problem. Her lab results had been inconsistent, numbers that didn't match how she actually felt. In hindsight, she realized the biotin was likely the culprit.
Dulmage, who published her findings in JCO Oncology Practice, is pushing oncologists to have explicit conversations with their patients about hair loss and the hidden risks of biotin. The challenge is that biotin's interference isn't limited to cancer monitoring. The supplement can also affect troponin levels, a marker of heart attack. A patient can't simply stop taking biotin before an unplanned emergency test—which means the safest approach is not to take it at all, especially since true biotin deficiency is extraordinarily rare. The vitamin is abundant in everyday foods: fruits, vegetables, eggs, dairy, meat.
For patients desperate to address hair loss, Dulmage recommends minoxidil instead. It's FDA-approved, available over the counter in topical forms, and actually works—without interfering with cancer monitoring. Malagoli has tried both and found minoxidil more effective. "I would say it's super important to listen to your doctors and not just do your thing," she reflected. The stakes of doing your own thing, it turns out, are higher than most patients realize.
Notable Quotes
The supplements may cause inaccurate lab results, resulting in a delay or change in patients' treatment plans— Dr. Brittany Dulmage, oncodermatologist at Ohio State University
My lab results were inconsistent. They just didn't balance out with what I was feeling, so that was a red flag— Anna Malagoli, breast cancer survivor
The Hearth Conversation Another angle on the story
Why would cancer patients specifically be drawn to biotin when they're already dealing with so much?
Hair loss from chemotherapy is one of the most visible, identity-altering side effects of cancer treatment. It's not just a medical problem—it's a daily mirror of what you've been through. When you're told your cancer is gone, you want to look like you're gone too. Biotin is marketed as natural, harmless, and available without a prescription. It feels like taking control back.
But the real danger isn't that biotin doesn't work for hair. It's that it breaks the tests that catch cancer coming back.
Exactly. The irony is brutal. A patient takes biotin to feel better about their appearance while they're trying to heal, and it silently corrupts the very blood tests designed to keep them alive. The lab results become a false mirror.
How many patients are we talking about here?
Dulmage sees more than half of her hair-loss patients already on biotin when they arrive. That's not a fringe behavior—that's mainstream. And many of them found the information online or heard about it from other patients, not from their oncologists.
So the system failed them first by not warning them.
Yes. Patients are trying to solve a real problem—hair loss—with information that's available and seems safe. The medical system hasn't been proactive about saying, 'Don't do this.' Dulmage's work is trying to change that.
What's the alternative? Can they just stop taking biotin before their blood work?
That's the trap. Some blood work is planned—you can stop biotin 72 hours before. But emergencies don't announce themselves. A patient can't stop taking biotin before a heart attack happens, and biotin interferes with troponin tests. The safest answer is just not to take it.
And minoxidil actually works?
It's FDA-approved and it does. Malagoli noticed the difference herself. It's not perfect—you have to use it consistently—but it's safe and it doesn't hide cancer.