Supplements I would stop taking today, and why
When a new client puts her bottles on my table there are usually 9 or 10 of them, and she can tell me why she started about half. Some of those bottles are quietly changing the bloodwork she is worried about. A hair gummy can make a thyroid test read wrong. An iron pill nobody tested for can push a liver number up. A turmeric capsule can do the same. This is the short list I would stop today, or before your next blood draw, with the reason for each. If a doctor prescribed any of them, you keep taking them until you have talked to that doctor.
Why I start with the bottles
I read lab folders for a living, and the folder makes more sense once I know what was in the cabinet the week the blood was drawn. A supplement is a dose. It gets into the blood the same way a medication does, and some of them show up on the panel in ways that look like disease. Nobody told the doctor, because the form at the front desk asked about medications and these did not feel like medications. They are.
Biotin before any blood test
Biotin is the hair, skin and nails vitamin. You need about 30 micrograms a day. The beauty formulas carry 5,000 to 10,000 micrograms, and some go to 20,000, which is hundreds of times the requirement.
The biotin itself is harmless at those doses. The lab is where it goes wrong. Many common blood tests use biotin inside the test chemistry, and a flood of it from a supplement throws the result. The FDA has warned about this since 2017 and updated the warning in 2019. Thyroid tests are the ones that matter for my readers. High dose biotin can make TSH read falsely low and T4 falsely high, which looks exactly like an overactive thyroid on paper. It can also make a troponin test, the one used to check for a heart attack, read falsely low, which is why the FDA cares.
I would stop biotin at least 3 days before any blood test and tell the person drawing your blood that you take it. If you have had a strange thyroid result while on a hair formula, ask for the repeat off biotin.
Iron you never tested for
Iron is the supplement women in their forties are told to take by everyone, and it is the one I would never take without a number. Ferritin is that number. The American Society of Hematology published new guidance in 2026 that calls a ferritin of 30 or lower iron deficiency in adults, and says a cutoff of 50 may be considered for women with heavy periods. Low iron is real and common.
The other side is just as real. About 1 in 200 to 400 people in the United States and Europe has hemochromatosis, most often with Irish or Scandinavian ancestry. The body stores iron it cannot get rid of, and the liver, joints and heart take the damage. A woman with that pattern often has no idea until her periods stop and the iron starts to climb. Add a daily iron pill and you speed it up. Iron also irritates the gut, iron that builds up pushes the liver enzymes I watch, and the upper limit from supplements for adults is 45 milligrams a day unless a doctor is managing a deficiency.
If you take iron and nobody has ever run your ferritin, I would stop until it is run. If ferritin comes back low, iron is the right answer and your doctor sets the dose. If it comes back high, you ask for a transferrin saturation and a conversation.
The liver list
If your ALT has been creeping up and you do not drink much, I want to know about these 6 before I believe it is your diet: turmeric or curcumin, green tea extract, ashwagandha, black cohosh, garcinia cambogia and red yeast rice. A 2024 study in JAMA Network Open estimated that 15.6 million American adults had taken at least one of them in the past month. In the national registry of liver injury, herbal and dietary supplements rose from 7 percent of cases to 20 percent between 2004 and 2013.
Turmeric surprises people most. In food it is fine. In capsules, especially the high absorption kind paired with black pepper extract, it has been linked to a growing number of liver injury reports, some of them serious. Green tea extract is a known liver risk above roughly 800 milligrams of EGCG a day, a dose easy to reach in a fat burner and impossible to reach from cups of tea. Ashwagandha has its own liver reports, and it can push thyroid hormone up, which matters if you take thyroid medication or are about to be tested. Red yeast rice contains the same molecule as the statin lovastatin at a dose that varies from bottle to bottle, so it carries statin side effects without statin supervision. Black cohosh is sold for hot flashes. If hot flashes are the reason you take it, hormone therapy is the most effective treatment there is, and that is a conversation for a menopause trained doctor.
A supplement is a dose. If it can help the liver, it can hurt the liver.
I would stop every product on that list before your next liver panel and tell your doctor you stopped. If ALT comes down over 2 to 3 months, you have your answer. If it does not, the workup moves on to fatty liver, insulin and the other things I wrote about in Issue 014.
"Adrenal support" and "thyroid support" blends
These worry me more than anything else on the table, because they are sold to exhausted women as food and sometimes they contain hormones. In 2018 researchers at Mayo Clinic bought 12 adrenal support supplements and tested them. All 12 contained thyroid hormone, and most contained at least one steroid hormone, with none of it on the label. That is an unmeasured dose of the exact hormones your doctor is trying to measure.
Thyroid support blends carry a different risk. Most are built on iodine, often from kelp, at doses far above the 150 micrograms you need and sometimes above the 1,100 microgram ceiling. Too much iodine can tip a thyroid in either direction, and with Hashimoto's antibodies it can make things worse. If you take thyroid medication, a thyroid support blend can change your levels without anyone knowing why. I would stop both kinds today and tell your prescriber, because your dose may have been set while the blend was in your system.
Melatonin gummies and detox teas
2 small ones. A 2023 study in JAMA tested 25 melatonin gummies and found 22 were mislabeled, with the real dose ranging from about three quarters of the label to three and a half times it. One contained no melatonin at all. If you want to use melatonin, use a low dose from a product with third party testing, treat it as a short term tool, and work on the sleep itself, which I wrote about in Issue 022.
Detox teas are usually senna, a stimulant laxative. Daily stimulant laxatives teach the bowel to wait for them, and the "flat stomach" effect is water and stool leaving. Fat does not leave that way. For anyone with a history of disordered eating these teas are a risk, and I would ask for help stopping rather than stopping alone.
What I would do first
I would put every bottle on the table and write a list with the dose of each ingredient. Include gummies, powders, teas and drinks. Mark each one with the reason you take it. If you cannot name the reason, that is reason enough to stop.
I would stop biotin, iron you never tested for, the 6 liver botanicals, and any adrenal or thyroid blend today. Then I would book a blood draw for 2 to 3 weeks out so the panel shows your body without them.
I would ask for ferritin before restarting iron, and for ALT, AST and a full thyroid panel after the botanicals are gone. If you are pregnant, taking blood thinners, thyroid medication or diabetes medication, take the list to the prescriber before changing anything, because stopping can shift a dose just as starting can.
I would keep what has a reason and a number. Vitamin D if you were tested low. Magnesium if it helps constipation, under 350 milligrams. Iron if ferritin says so. If you want a day by day plan for eating well while you rebuild, that is what the Whole Reset workbook is, at $49 with shipping, and it starts with food rather than bottles.
When to push harder with your doctor
Yellowing of the skin or eyes, dark urine, pale stools or pain under the right ribs while taking any botanical needs same day attention. Stop the product and bring the bottle.
If a thyroid result came back wild while you were on a hair formula, ask for a repeat off biotin before anyone treats it.
If you have taken iron for years without a test, ask for ferritin and transferrin saturation, and mention any family member with liver trouble or unexplained diabetes.
If your doctor waves the list away, ask for it to be put in your chart anyway.
FAQ
Is it safe to stop all my supplements at once?
For the ones in this note, yes, because none of them are treating a diagnosed deficiency. The exceptions are anything a doctor prescribed, and iron or vitamin D if a test showed you were low. Take the list to your prescriber if you are on thyroid medication, blood thinners or diabetes medication.
How long before a blood test should I stop biotin?
At least 3 days, and longer is safer for high doses. Tell the lab and your doctor you take it either way. A hair gummy with 10,000 micrograms can throw thyroid and heart tests.
Can turmeric really hurt your liver?
In food, no. In concentrated capsules, especially the high absorption kind with black pepper extract, there are hundreds of reported liver injuries, some serious. If your ALT is rising, stop it and retest in 2 to 3 months.
Should I take iron in perimenopause?
Only with a ferritin result. Low iron is common with heavy periods, and the 2026 hematology guidance calls 30 or lower deficient, with 50 as a possible cutoff for heavy bleeders. High iron is also real and inherited, and iron pills make it worse.
What is wrong with adrenal support supplements?
A 2018 study tested 12 of them and found thyroid hormone in all 12 and steroid hormones in most, none of it on the label. That is an unmeasured hormone dose. If you are tired, ask for the workup instead: ferritin, a full thyroid panel and fasting insulin.
In good health,
Yvette Rose
Sources
- US Food and Drug Administration. The FDA warns that biotin may interfere with lab tests. Safety communication, 2017, updated 2019.
- Li D et al. Association of biotin ingestion with performance of hormone and nonhormone assays in healthy adults. JAMA, 2017.
- Powers JM et al. American Society of Hematology 2026 guidelines for diagnosis of iron deficiency. Blood Advances, 2026.
- Likhitsup A, Chen VL, Fontana RJ. Estimated exposure to 6 potentially hepatotoxic botanicals in US adults. JAMA Network Open, 2024.
- Navarro VJ et al. Liver injury from herbals and dietary supplements in the US Drug Induced Liver Injury Network. Hepatology, 2014.
- EFSA. Scientific opinion on the safety of green tea catechins. EFSA Journal, 2018.
- Akturk HK et al. Over the counter adrenal support supplements contain thyroid and steroid based adrenal hormones. Mayo Clinic Proceedings, 2018.
- Cohen PA et al. Quantity of melatonin and CBD in melatonin gummies sold in the US. JAMA, 2023.
- Kane SF, Roberts C, Paulus R. Hereditary hemochromatosis: rapid evidence review. American Family Physician, 2021.
- NIH Office of Dietary Supplements. Iron fact sheet for health professionals.
- NIH Office of Dietary Supplements. Iodine fact sheet for health professionals.
This is general wellness education and not medical advice, diagnosis or treatment. Talk to a qualified professional, especially if you are pregnant, nursing, taking medication or managing a condition.