Who Shouldn't Take Biotin? A Comprehensive Guide

November 17, 2025 •

4 min read

According to the Food and Drug Administration (FDA), high doses of biotin can cause dangerously misleading results in certain lab tests, including those for heart attacks. Given this significant risk, understanding who shouldn't take biotin is crucial for avoiding serious misdiagnoses and health complications.

Quick Summary

This guide details the specific groups of people who should avoid or use caution with biotin supplements. It covers how high doses can interfere with critical medical tests, interact with certain medications, and impact individuals with pre-existing conditions like diabetes or kidney disease.

Key Points

Lab Test Interference: High doses of biotin can cause dangerously inaccurate results in critical medical tests, including those for heart attacks and thyroid function.
Diabetes Risk: Biotin can affect blood sugar levels, posing a risk to individuals with diabetes, especially those on glucose-regulating medication.
Kidney Concerns: People with kidney disease may have difficulty clearing excess biotin, potentially straining already weakened kidneys.
Drug Interactions: Certain medications, notably anticonvulsants, can interact with biotin, affecting both the vitamin's and the drug's effectiveness.
Pregnancy and Breastfeeding: While important for fetal health, high-dose biotin supplements should be avoided by pregnant and breastfeeding individuals unless directed by a doctor.
Pre-existing Conditions: Individuals with underlying health issues should consult a doctor before starting biotin, as it can complicate some medical conditions.
Genetic Deficiencies: People with a rare biotinidase deficiency must take biotin, but only under strict medical supervision.

Biotin Supplementation: Understanding the Risks

Biotin, or vitamin B7, is a water-soluble vitamin popular for its purported benefits for hair, skin, and nails. However, unlike many water-soluble vitamins, an excess amount is not always harmlessly excreted. High-dose supplementation presents several significant risks, primarily related to medical diagnoses and pre-existing health conditions. While a balanced diet typically provides sufficient biotin for most healthy individuals, certain groups should exercise extreme caution or avoid supplementation altogether.

Lab Test Interference and the Risk of Misdiagnosis

One of the most critical reasons certain individuals should not take biotin is its potent ability to interfere with a wide array of laboratory tests. Many immunoassay tests use biotin technology, and an excess of the vitamin in the blood can significantly skew the results. This can lead to false positives or false negatives, with potentially life-threatening consequences.

Tests most commonly affected include:

Cardiac Troponin Tests: Used to diagnose heart attacks, biotin interference can cause a falsely low reading, leading to a missed or delayed diagnosis.
Thyroid Function Tests: Biotin can cause falsely high or low thyroid hormone results, leading to an incorrect diagnosis of hyperthyroidism or hypothyroidism.
Hormone Assays: Tests for other hormones, such as parathyroid hormone, cortisol, and vitamin D, can also produce inaccurate results.

For anyone scheduled for lab work, informing the doctor and lab personnel about biotin use is paramount. Healthcare providers may advise discontinuing supplementation for several days before testing to ensure accurate results.

Biotin and Pre-existing Medical Conditions

Certain health conditions can be exacerbated or complicated by high-dose biotin intake. Individuals with these conditions should seek medical advice before considering any supplementation.

Diabetes

Research indicates that high doses of biotin can affect glucose and insulin levels. In some studies, biotin supplements lowered fasting blood sugar, but the overall effect on diabetes management can be complex and unpredictable. For individuals on insulin or other blood sugar-lowering medications, biotin supplementation could dangerously affect glucose control, potentially leading to abnormally low blood sugar (hypoglycemia) if not properly monitored.

Kidney Disease

Biotin is water-soluble and is excreted by the kidneys. For individuals with impaired kidney function, the body's ability to clear excess biotin may be reduced, potentially increasing strain on the kidneys. Although research on biotin's direct harm to kidneys is limited, patients with chronic kidney disease (CKD) should always consult a nephrologist before supplementing. They may require a specific, physician-guided dosage, as some patients on dialysis may actually have a deficiency.

Drug Interactions

Biotin has the potential to interact with specific medications, reducing their effectiveness or increasing side effects.

Anticonvulsants

Some anti-seizure medications, such as carbamazepine, phenobarbital, and phenytoin, can lower biotin levels in the body by interfering with its absorption. This can create a need for supplementation in those taking these drugs, but the dosage must be carefully managed by a healthcare provider.

Other Medications

Biotin may interact with other drugs metabolized by the liver. Taking biotin alongside certain medications, including some for cholesterol and diabetes, could alter their breakdown and affect their efficacy or side effect profile. A comprehensive review with a doctor or pharmacist is essential to avoid negative interactions.

Comparison of Biotin Risks


Risk Factor	Who is at Risk?	Primary Concern	Actions to Take
Lab Test Interference	Anyone undergoing sensitive immunoassay tests (e.g., cardiac troponin, thyroid).	Misdiagnosis, delayed treatment, and potentially deadly outcomes.	Inform doctors and lab staff of biotin use; discontinue supplementation before testing as advised.
Diabetes	Individuals with Type 1 or Type 2 diabetes, especially those on insulin or other glucose-regulating drugs.	Interference with glucose control, potential for hypoglycemia or hyperglycemia.	Consult a healthcare provider before use and monitor blood sugar closely.
Kidney Disease	People with impaired kidney function or on dialysis.	Potential strain on already compromised kidneys due to impaired clearance.	Seek advice from a nephrologist; a specific dose may be needed.
Drug Interactions	Patients taking anticonvulsants or other liver-metabolized drugs.	Reduced effectiveness of medication; altered drug levels in the bloodstream.	Disclose all medications and supplements to a doctor or pharmacist.

Pregnancy and Breastfeeding Considerations

While biotin is an important nutrient for fetal development, excessive amounts should be avoided. The standard recommended intake of biotin for pregnant or breastfeeding individuals is generally met through a balanced diet and prenatal vitamins. High doses from separate supplements could be harmful and should not be taken without explicit medical supervision.

Individuals with Biotinidase Deficiency

Some individuals have a rare genetic disorder called biotinidase deficiency, which prevents their body from properly using and recycling biotin. These individuals may require biotin supplementation, but it must be managed under strict medical guidance. This represents an exception where supplementation is necessary due to a specific medical condition, rather than for general health or cosmetic reasons.

Conclusion: Always Consult a Healthcare Provider

Ultimately, the decision to take biotin supplements should not be made without professional medical advice, especially for individuals in the at-risk categories. While generally considered safe for healthy people at normal dietary levels, high-dose biotin carries a serious risk of interfering with critical medical tests and can complicate pre-existing conditions or medication regimens. Always inform your healthcare providers about all supplements you are taking to ensure accurate diagnoses and treatment.

For more in-depth information about the potential dangers of biotin interference with medical tests, consult the FDA's official safety alert.

Frequently Asked Questions

Those most at risk include individuals with pre-existing medical conditions like diabetes or kidney disease, patients undergoing lab tests (especially for heart or thyroid issues), and people taking certain medications like anticonvulsants.

You should not take biotin supplements without consulting a nephrologist. While some individuals with kidney issues may have a deficiency requiring supplementation, impaired kidney function can hinder the body's ability to excrete excess biotin, potentially causing complications.

Biotin interferes with certain lab tests, known as immunoassays, because they use biotin technology to function. Excess biotin in the blood can disrupt these tests, leading to falsely high or falsely low results, which can cause dangerous misdiagnoses.

Your healthcare provider should advise you on the specific timing, but it is often recommended to stop taking biotin supplements for at least 48 to 72 hours before a scheduled blood draw.

Biotin is important during pregnancy, but excessive amounts should be avoided. The recommended daily intake is usually covered by a prenatal vitamin and a healthy diet. High-dose supplements should only be taken with a doctor's explicit approval.

Yes, biotin can interact with certain medications. For example, some anti-seizure drugs can lower biotin levels, while high-dose biotin can interfere with medications metabolized by the liver. Always inform your doctor about all supplements you are taking.

While difficult to overdose on biotin due to its water-soluble nature, excessive intake can lead to symptoms like insomnia, excessive thirst, increased urination, skin rashes, and digestive upset. Severe reactions are rare but possible.