When Should You Not Take Biotin? Essential Warnings and Precautions

October 8, 2025 •

4 min read

According to the FDA, high-dose biotin can significantly interfere with certain lab tests, causing incorrect and potentially dangerous results. Knowing when should you not take biotin? is crucial to avoid misdiagnoses and unintended health complications from supplements marketed for hair, skin, and nail health.

Quick Summary

It is crucial to understand that biotin supplements, particularly in high doses, can interfere with common lab tests, interact with certain medications, and potentially affect individuals with pre-existing health conditions. Always consult a healthcare provider before beginning supplementation.

Key Points

Stop Before Lab Tests: High-dose biotin can severely interfere with diagnostic lab tests for heart attacks (troponin) and thyroid conditions (TSH), potentially leading to false results and misdiagnosis.
Inform Your Doctor: Always tell your healthcare provider if you take biotin, especially before any blood draw, as they may instruct you to stop taking it for 24-72 hours beforehand.
Review Medication Interactions: Be cautious if taking anti-seizure medications or long-term antibiotics, as these can negatively affect your body's biotin levels.
Avoid Excessive Raw Egg Whites: A protein called avidin in raw egg whites binds to biotin and prevents its absorption. Cooking eggs eliminates this risk.
Proceed with Caution for Health Conditions: Individuals with kidney disease, diabetes, or inherited biotin metabolism disorders should only take biotin under strict medical supervision.
Recognize Side Effects: Though rare, high doses can cause side effects like digestive upset, acne, or insomnia, which typically resolve when supplementation is stopped.

Biotin and Lab Test Interference

One of the most critical reasons to temporarily stop taking biotin is before any scheduled blood work. High doses of biotin can cause significant interference with common laboratory tests, leading to falsely high or low results and potentially a misdiagnosis. The FDA has issued safety warnings about this issue, and the consequences can be severe, especially concerning time-sensitive medical evaluations.

Types of tests affected by biotin

Biotin interference primarily impacts immunoassays, which use biotin-streptavidin technology to detect specific markers. Tests known to be affected include:

Troponin tests: Used to diagnose heart attacks. Falsely low results can delay crucial treatment.
Thyroid function tests: This includes thyroid-stimulating hormone (TSH), free T3, and free T4. Biotin can cause false high or low results, which may lead to an incorrect thyroid disorder diagnosis.
Hormone tests: Tests for hormones like parathyroid hormone (PTH), follicle-stimulating hormone (FSH), and others can be affected.
Vitamin D tests: Incorrect results for Vitamin D levels have also been reported.

How to prevent interference

Most healthcare providers recommend that patients stop taking biotin supplements for at least 72 hours before a blood test, especially for high-dose regimens. For those on standard doses, waiting at least 8 hours may suffice, but it's always best to follow a doctor's specific instructions.

Drug and Substance Interactions

Certain medications and habits can interfere with how your body processes biotin, and vice-versa. Informing your doctor about all supplements you take is essential for managing potential interactions.

Medications that affect biotin levels

Anticonvulsants: Long-term use of anti-seizure medications like carbamazepine, phenytoin, and phenobarbital can lower biotin levels in the body by interfering with its intestinal absorption and increasing its breakdown.
Antibiotics: Prolonged antibiotic use can disrupt the beneficial bacteria in the gut that produce biotin, potentially leading to lower levels.

Substances that inhibit biotin absorption

Raw Egg Whites: Consuming large quantities of raw egg whites over an extended period can lead to biotin deficiency. The protein avidin in raw egg whites binds tightly to biotin, preventing its absorption by the body. Cooking denatures avidin, making cooked eggs a safe source of biotin.
Alcohol: Chronic alcohol consumption inhibits the absorption of biotin, placing heavy drinkers at a higher risk of deficiency.

Health Conditions Requiring Caution

While biotin is generally safe, certain medical conditions necessitate a doctor's supervision before starting supplementation.

Kidney disease and dialysis

Since excess biotin is primarily excreted through the kidneys, individuals with pre-existing kidney disease or those undergoing dialysis may place an additional strain on their kidneys with high-dose supplementation. A doctor should monitor biotin intake closely in these cases.

Genetic disorders

Rare, inherited conditions like biotinidase deficiency or holocarboxylase synthetase deficiency prevent the body from properly recycling or utilizing biotin. Lifelong supplementation under a doctor's care is required for individuals with these disorders, who are often identified through newborn screening.

Diabetes

Individuals with diabetes should be cautious with biotin supplements. High doses may affect blood sugar levels, and interference with certain lab tests could lead to misleading results regarding their condition.

Table: Biotin Use vs. Avoidance Scenarios


Scenario	Rationale	Recommendation
Before a lab test	High doses interfere with immunoassays, potentially causing false readings for troponin and thyroid hormones.	Stop taking biotin 24-72 hours before the test; inform your doctor and lab.
Taking anticonvulsants	These medications can decrease the body's biotin levels by impairing absorption.	Discuss with your doctor whether you require a higher dose to compensate or if other adjustments are needed.
Kidney disease or dialysis	Excretion of excess biotin is managed by the kidneys; high doses can cause undue strain.	Consult a doctor for guidance on safe intake levels.
Regular raw egg white consumption	The protein avidin binds to biotin, preventing absorption and potentially causing a deficiency.	Cook eggs thoroughly to denature avidin; address deficiency through a balanced diet or, if necessary, with supplements under a doctor's supervision.
No known deficiency or underlying condition	Deficiency is rare, and robust evidence for supplement benefits on hair, skin, and nails in healthy individuals is lacking.	Most healthy people do not need high-dose biotin supplements; focus on a balanced, biotin-rich diet instead.

Risks of Taking Biotin Without a Confirmed Deficiency

In healthy individuals, biotin deficiency is extremely rare. The body can obtain adequate amounts from a balanced diet, and gut bacteria also produce some biotin. Taking high doses without a medical reason offers no proven additional benefits for hair, skin, or nail health and can carry unnecessary risks.

Potential side effects from high doses

While biotin is water-soluble and any excess is typically excreted, high-dose supplementation can still cause side effects in some people. These may include:

Mild digestive issues, such as nausea, cramping, and diarrhea.
Acne flare-ups, potentially due to interference with the absorption of other B vitamins.
Insomnia, as excess biotin may cause a boost of energy that disrupts sleep patterns.

Conclusion: Prioritize Medical Consultation

While biotin is a vital nutrient, it is not a 'magic pill' for everyone, and supplementation is not always appropriate or necessary. The most significant risks are associated with high-dose supplements, particularly their interference with critical medical lab tests. Therefore, it is paramount to inform your healthcare provider about any biotin you are taking before undergoing lab work or if you have pre-existing medical conditions. A balanced diet is the best source of biotin for most people, making unnecessary supplementation an avoidable health risk.

For more detailed information on biotin and nutrient safety, consult reputable health authorities, such as the NIH Office of Dietary Supplements.

Frequently Asked Questions

Yes, high-dose biotin supplements can significantly interfere with thyroid function tests, including those for TSH, T3, and T4, causing misleading results that can lead to incorrect diagnoses.

To prevent interference with lab results, healthcare providers often advise stopping high-dose biotin for at least 72 hours before a blood draw. For lower doses in multivitamins, informing your doctor is still recommended.

Medications that can interfere with biotin include certain anti-seizure drugs (e.g., carbamazepine, phenytoin) and prolonged use of oral antibiotics, which can disrupt the gut bacteria that produce biotin.

While marginal biotin deficiency is common during pregnancy, supplementation should only be done under a doctor's guidance. Pregnant and lactating women have altered nutrient demands, so a doctor's consultation is essential.

Raw egg whites contain a protein called avidin that strongly binds to biotin. This binding makes the biotin unavailable for absorption by the body, potentially leading to a deficiency with excessive intake.

Though rare, an allergic reaction to biotin is possible. Symptoms can include hives, difficulty breathing, or swelling of the face, lips, or throat, and require immediate medical attention.

Common side effects of high doses of biotin, though generally mild, can include digestive issues like nausea or diarrhea, skin rashes, and acne. High doses may also contribute to insomnia.