Who Should Avoid Taking Biotin?

December 27, 2025 •

3 min read

According to the FDA, high-dose biotin can significantly interfere with certain lab tests, leading to incorrect results and potentially dangerous misdiagnoses. This surprising fact means that despite its popularity for hair and nails, biotin is not safe for everyone, especially those with pre-existing conditions or medical appointments on the horizon.

Quick Summary

Several groups should exercise caution with biotin supplementation, including individuals undergoing specific lab tests, those with compromised kidney function, and people on certain anticonvulsant medications. Consulting a healthcare provider is essential to determine if biotin is appropriate and at what dosage to minimize risks.

Key Points

Lab Test Interference: High-dose biotin can cause falsely high or low results on numerous lab tests, including those for heart attacks and thyroid function, potentially leading to misdiagnosis.
Kidney Disease: Since the kidneys excrete excess biotin, individuals with kidney disease should be cautious with supplementation to avoid potential strain.
Medication Interactions: Certain anticonvulsant drugs can affect biotin metabolism, so patients on these medications should seek medical advice.
Pregnancy and Breastfeeding: While biotin is important during pregnancy, high-dose supplementation should be avoided unless directed by a doctor.
Allergies and Conditions: Individuals with a biotin allergy or the rare genetic disorder biotinidase deficiency should be medically monitored for proper dosage.
Smoking: People who smoke have accelerated biotin breakdown and may require different dosing, so medical consultation is necessary.
Consult a Doctor: It is essential for anyone considering high-dose biotin to speak with a healthcare provider, especially if they have pre-existing conditions or upcoming medical tests.

Biotin and Lab Test Interference

Perhaps the most critical reason for certain individuals to avoid biotin is its potential to skew lab test results. High levels of biotin in the blood can interfere with certain immunoassays that rely on biotin-streptavidin technology. This can lead to falsely high or low test results, which may cause a misdiagnosis or result in inappropriate medical treatment. The FDA has issued a safety communication addressing this risk. For more information on affected tests, refer to {Link: Testing.com https://www.testing.com/articles/biotin-affects-some-blood-test-results/}.

To mitigate this risk, patients are typically advised to stop taking biotin supplements for at least 48 hours to a week before any blood test, depending on the dosage. It is vital to inform your doctor and lab personnel about any supplements you are taking.

Biotin and Specific Medical Conditions

While biotin is generally considered safe, certain medical conditions warrant caution or avoidance of supplementation.

Kidney disease and dialysis

Since biotin is a water-soluble vitamin, excess amounts are normally excreted through the kidneys. For individuals with impaired kidney function, this process is less efficient, potentially leading to a buildup of biotin in the body. While there is no evidence that biotin is directly harmful to kidneys, it could place additional strain on the organs, especially at high doses. Patients with chronic kidney disease (CKD), particularly those on dialysis, should always consult their nephrologist before starting any new supplement.

Biotinidase deficiency

This rare genetic disorder affects the body's ability to recycle biotin. People with this condition require biotin supplementation, but a doctor's supervision is necessary to manage the dosage correctly.

Diabetes

Some research suggests that high doses of biotin might affect blood sugar regulation. Individuals with diabetes should consult their doctor before taking biotin.

Drug and Lifestyle Interactions with Biotin

Several factors can affect biotin's efficacy and safety.

Medications

Certain medications can interfere with biotin metabolism or absorption. Anticonvulsant medications, such as carbamazepine, phenobarbital, phenytoin, and primidone, have been shown to potentially lead to lower biotin status. Individuals on these medications should consult their healthcare provider.

Pregnancy and breastfeeding

While important for fetal development, high doses of biotin are not recommended during pregnancy or breastfeeding. Mild deficiency can occur during pregnancy, but supplementation should only be done under a doctor's guidance. Prenatal vitamins generally contain an appropriate amount of biotin.

Smoking

Research indicates that smoking accelerates the breakdown of biotin in women. Smokers may require a different dosage, and a healthcare provider's input is necessary.

Raw egg whites

Consuming raw egg whites regularly can lead to biotin deficiency because they contain avidin, which prevents biotin absorption. Cooking denatures avidin.

High-Dose vs. Low-Dose Biotin


Factor	Low-Dose Biotin (e.g., standard multivitamin)	High-Dose Biotin (e.g., beauty supplements)
Dosage	Typically ≤ 30 mcg per day.	Can be thousands of times higher, often 2.5 mg to 10 mg or more.
Lab Test Interference	Unlikely to cause interference with lab tests.	Significant risk of interfering with many immunoassays, leading to false results.
Gastrointestinal Side Effects	Generally well-tolerated with minimal risk.	Can cause mild side effects like nausea, stomach cramps, or diarrhea.
Skin Side Effects	Low risk of adverse skin reactions.	Higher risk of causing acne or skin rashes.
Kidney Strain	Negligible risk for most individuals.	Potential for increased strain on kidneys, especially in those with pre-existing conditions.
Purpose	To prevent or treat biotin deficiency.	Often marketed for hair, skin, and nail health, though evidence for healthy individuals is limited.

Conclusion

While biotin is a vital nutrient, supplementation, especially in high doses, is not suitable for everyone. Individuals with scheduled lab work must temporarily discontinue biotin to avoid potentially life-threatening misdiagnoses. Those with kidney disease, those on anticonvulsant drugs, and pregnant or breastfeeding women should proceed with medical supervision. For the general population, a balanced diet provides sufficient biotin, and the benefits of high-dose supplements are not scientifically proven for healthy individuals. The golden rule is always to consult a healthcare professional before starting any new supplement regimen. More information is available from the {Link: Testing.com https://www.testing.com/articles/biotin-affects-some-blood-test-results/}.

Frequently Asked Questions

Many lab tests use a biotin-streptavidin technology for detection. High levels of biotin in a blood sample can interfere with this technology, causing inaccurate test results that may be either falsely high or falsely low.

Tests for heart attacks (troponin), thyroid function (TSH, T3, T4), and hormone levels (PTH, cortisol, FSH, LH) are commonly affected. Other immunoassays may also be compromised.

While the duration can vary depending on the dosage, many healthcare providers and labs recommend stopping biotin supplements for at least 48 hours to a week before a blood draw to ensure accurate results.

Excess biotin is excreted by the kidneys. While typically safe, high doses could potentially put additional strain on the kidneys, especially in individuals with pre-existing kidney disease or compromised function.

Biotin is essential during pregnancy, but excessive supplementation should be avoided. A standard prenatal vitamin typically contains a safe, recommended amount. Any additional supplementation should be discussed with a doctor.

Yes, some medications, particularly certain anticonvulsants used to treat seizures, can affect biotin levels. Patients on these drugs should consult a healthcare provider.

While severe overdose is rare, high doses can cause mild side effects such as nausea, digestive upset, increased acne, skin rashes, and increased thirst and urination.

Yes, getting biotin from dietary sources is the safest and recommended way for most people. A balanced diet provides sufficient biotin, and food-based biotin does not cause the same issues as high-dose supplements.