Are There Any Negatives to Taking Biotin? The Serious Risks You Should Know

October 12, 2025 •

3 min read

While commonly promoted for hair, skin, and nail health, the U.S. Food and Drug Administration (FDA) has issued safety alerts concerning high-dose biotin supplements. In a significant finding, they have warned that biotin can interfere with certain lab tests, leading to incorrect and potentially dangerous results. So, are there any negatives to taking biotin? This raises critical questions about its true safety profile, particularly at high doses found in many supplements.

Quick Summary

High-dose biotin can disrupt lab test results, potentially leading to misdiagnosis of serious conditions like heart attacks and thyroid disease. Other negatives include digestive issues, skin problems like acne, and interactions with certain medications.

Key Points

Lab Test Interference: High-dose biotin can cause falsely high or low results on critical lab tests, including those for heart attacks and thyroid disease, potentially leading to misdiagnosis.
Side Effects: Some individuals may experience digestive upset (nausea, cramping) and skin issues, such as acne, from high-dose biotin supplements.
Medication Interactions: Biotin can interact with certain medications, including anticonvulsants, and may affect how the liver processes other drugs.
Pre-Test Precautions: To avoid skewed test results, it is recommended to stop taking biotin supplements for at least 72 hours before a blood draw.
Diet Over Supplements: Most healthy individuals get enough biotin from food alone, and supplementation may not be necessary or provide added benefits.
Rare Toxicity: Biotin is water-soluble, so excess is typically excreted, and severe toxicity is rare, but high doses can still cause adverse effects.

Unpacking the Primary Concern: Biotin and Lab Test Interference

The most significant negative associated with taking high-dose biotin supplements is their potential to interfere with laboratory tests. The FDA has issued warnings due to increased reports of adverse events related to this interference. This can cause falsely high or low results, depending on the test.

The Mechanism of Interference

Many common lab tests use biotin-streptavidin technology. This method relies on the strong bond between biotin and streptavidin to measure various substances. High levels of supplemental biotin in the blood can interfere with this process, disrupting the test's accuracy.

Clinically Significant Impact

This interference can have serious consequences. For example, biotin can lead to falsely low cardiac troponin results, a key indicator for heart attacks, potentially causing missed diagnoses and delayed treatment. It can also skew thyroid hormone test results, like TSH, potentially leading to a misdiagnosis of thyroid conditions.

List of common tests susceptible to biotin interference:

Cardiac Troponin Tests: Used to detect heart attacks.
Thyroid Function Tests: Such as TSH, T3, and T4.
Hormone Assays: Including parathyroid and fertility hormones.
Pregnancy Tests: Both blood and some at-home urine tests.

Other Potential Side Effects of High-Dose Biotin

While biotin is water-soluble and generally considered safe, high doses from supplements can cause some individuals to experience less severe side effects. Since excess biotin is typically excreted in urine, the risk of serious toxicity is low, but adverse reactions are still possible.

Gastrointestinal Distress

Some people may experience digestive discomfort, such as nausea, cramping, or diarrhea.

Skin Issues

Despite being marketed for skin health, high doses can sometimes cause acne breakouts due to increased sebum production or, rarely, allergic reactions like rashes or hives.

Sleep and Energy

High levels of biotin may affect energy and sleep, potentially causing insomnia or increased thirst and urination.

Biotin and Medication Interactions

Biotin can interact with certain medications. Some anticonvulsants may lower biotin levels, while biotin can influence the liver's metabolism of other drugs. Always inform your doctor about all supplements you take to avoid potential drug interactions.

Risks vs. Benefits: A Comparison Table


Feature	Perceived Benefits of Biotin Supplements	Proven Risks of Biotin Supplements
Efficacy	Often marketed for improved hair, skin, and nail health. However, scientific evidence is limited unless a true biotin deficiency exists.	Documented interference with numerous laboratory tests, potentially leading to misdiagnosis.
Safety Profile	Considered safe for most people, especially when obtained from a healthy diet.	Potential for side effects such as digestive issues, acne, or rashes, especially with high doses.
Impact on Health	Supports metabolism and cellular processes. May be beneficial for rare deficiencies or specific conditions like multiple sclerosis, under medical supervision.	Risk of inaccurate test results for critical health markers like troponin, thyroid, and hormones.
Dependence	Most people get sufficient biotin from their diet and do not require supplementation.	No established upper tolerable limit due to lack of toxicity data, but high doses pose distinct risks.

Who Is Most at Risk?

Certain individuals face greater risks from biotin supplementation:

Individuals undergoing medical testing: Those with upcoming blood tests, especially for heart or thyroid conditions, should be aware of potential interference.
Patients with chronic conditions: People with diabetes or kidney disease should be cautious due to potential effects on blood sugar and kidney function.
Those taking multiple medications: Interactions are possible, requiring consultation with a healthcare provider.
Pregnant or breastfeeding women: Supplementation should only occur under medical guidance.

How to Minimize the Risks of Taking Biotin

To safely use biotin supplements:

Inform Your Doctor: Always disclose your biotin intake to healthcare providers and lab technicians.
Temporarily Stop Supplementation: Halt biotin for at least 72 hours before blood tests to ensure accuracy; longer may be needed for high doses.
Prioritize Diet over Supplements: A balanced diet with biotin-rich foods is often sufficient for most people. Supplementation is rarely medically necessary for deficiency.
Be Aware of Hidden Biotin: Biotin is in many multivitamins and other supplements; check labels carefully.

Conclusion: Informed Supplementation is Key

Taking biotin supplements, particularly at high doses, carries potential negatives, with interference in crucial lab tests being the most serious risk due to potential misdiagnosis. Other reported issues include digestive upset and skin problems. Since true biotin deficiency is uncommon, a balanced diet is usually adequate. Anyone considering supplementation, especially those with health conditions or upcoming tests, must consult a healthcare provider. Understanding these risks is vital for making informed decisions and preventing negative health outcomes.

For further details, consult the NIH Office of Dietary Supplements fact sheet.

Frequently Asked Questions

Biotin interferes with lab tests that use biotin-streptavidin technology. High levels of biotin in the blood can disrupt the test's ability to accurately measure the substance being tested, leading to incorrect results.

Commonly affected tests include cardiac troponin tests for heart attacks, various thyroid function tests (like TSH, T3, T4), hormone assays, and certain pregnancy tests.

Some individuals report mild side effects like digestive issues (nausea, cramping, diarrhea), skin problems such as acne or rashes, and insomnia from high doses.

To ensure accurate lab test results, it is generally recommended to stop taking biotin supplements for at least 72 hours (three days) before a blood draw. For very high doses, a longer period may be necessary.

Yes, for most healthy individuals, a balanced diet that includes biotin-rich foods like eggs, nuts, and organ meats provides a sufficient amount of the vitamin.

While biotin toxicity is rare because it is water-soluble and excess is excreted, extremely high doses can still lead to undesirable side effects. There is currently no established upper tolerable intake level.

People with upcoming medical tests, those with kidney or liver conditions, individuals taking anti-seizure or other medications, and pregnant women should exercise extra caution and consult a healthcare provider.