Biotin (Vitamin B7) is most often used for Skin, Hair, & Nails. The Examine Database covers Multiple Sclerosis, Type 2 Diabetes, and 2 other conditions and goals.

Evidence-based

Biotin (Vitamin B7)

Written by:

Daryl Nault, Katie Jantz

Fact-checked by:

Nick Milazzo, Giulia Guerrini

•Last Updated: September 4, 2025

Biotin is an essential B vitamin used by the body as a cofactor for several enzymes involved in metabolism. Biotin is commonly used to promote hair, skin, and nail health; however, this is not well supported by evidence.

Safety Information

New

Written by:

Fact-checked by:

Last Updated:September 4, 2025

Research Snapshot

44 references on this page

1,322 participants in 6 trials and 1 meta-analysis

Examine Evidence Grades

BTriglycerides + 1 more

C1 outcome

D5 outcomes

Overview

What is biotin?

What are biotin’s main benefits?

What are biotin’s main drawbacks?

How does biotin work?

Dosage Information

Formulations

Biotin is available as a single-ingredient oral tablet, capsule, gummy, or liquid. It is also commonly found in multi-ingredient supplements (e.g., B-complex vitamins, multivitamins, and formulas for hair, skin, and nails).

A high-dose, pharmaceutical-grade biotin (MD1003) has been used in studies on multiple sclerosis.^[1]

Range of dosages studies

Biotin has been studied at dosages ranging from 0.3 mg to 300 mg daily.

⚠️ Caution: Biotin dosages of 10 mg daily or more can interfere with several lab tests, potentially leading to misdiagnoses or the mismanagement of health conditions. Anyone who is supplementing with biotin should inform their healthcare practitioners.

Other considerations

Biotin AI

There is insufficient data to establish a recommended dietary allowance (RDA) for biotin. Instead, the adequate intake (AI) is the average amount of biotin consumed daily that appears to be nutritionally adequate for people without health conditions.^[2] Of note, the European Food Safety Authority (EFSA) recommends a higher AI for most age groups, including 40 μg daily for all adults and 45 μg for lactating women.^[3]

AGE	MALE	FEMALE	PREGNANT	LACTATING
0–6 months	5 μg	5 μg	—	—
7–12 months	6 μg	6 μg	—	—
1–3 years	8 μg	8 μg	—	—
4–8 years	12 μg	12 μg	—	—
9–13 years	20 μg	20 μg	—	—
14–18 years	25 μg	25 μg	30 μg	35 μg
19+ years	30 μg	30 μg	30 μg	35 μg

Reference: Institute of Medicine. Biotin (chapter 11 of Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. The National Academies Press. 1998. DOI: 10.17226/6015)

Bition UL

There is insufficient evidence to determine a tolerable upper intake level (UL) for biotin. There are no reported cases of toxicity in humans.^[2]^[4]

Supplements Demystified: Get Our Unbiased, Evidence-Based Guide

Uncover the truth about popular supplements like creatine, turmeric, garlic, zinc, melatonin, and more. Plus, we'll debunk myths surrounding multivitamins, testosterone boosters, and immune supplements.
Become a savvy supplement shopper. Learn how to spot the hidden signs of low-quality products and save money by avoiding ineffective supplements.
Demystify scientific studies. Develop the skill to sift through the jargon and make empowered decisions for your health.
Transform your lifestyle with easy-to-apply, practical health tips.
Bonus PDF: Also get Examine's Top 10 Most Popular Study Summaries over the past 12 months, covering gluten-free eating, calorie and time restricted eating, cognitive health, ashwaganda, muscle building, and more.

Examine Database: Biotin (Vitamin B7)

Health Condition/Goal	Health Outcome	Evidence
Multiple Sclerosis	2 outcomes	4 Studies
Type 2 Diabetes	6 outcomes	1 Study
General Cardiovascular Health	1 outcome	1 Study
Dyslipidemia	6 outcomes	3 Studies

Multiple Sclerosis

2 outcomes

Type 2 Diabetes

6 outcomes

General Cardiovascular Health

1 outcome

Dyslipidemia

6 outcomes

Safety InformationNew

Research FeedRead all studies

Frequently Asked Questions

What are the causes, signs, and symptoms of biotin deficiency?

What are the main dietary sources of biotin?

Does biotin affect hair, nail, or skin health?

Does biotin affect multiple sclerosis?

What are other names for Biotin (Vitamin B7)?

Update History

September 4, 2025

Safety Information added
major

Research written by

Katie Jantz

Edited by

Conni Covington

Reviewed by

Giulia Guerrini, Gregory Lopez & Louie Neri

September 12, 2023

More safety information added
minor

Research written by

Daryl Nault

Edited by

Natalka Roshak

Reviewed by

Nick Milazzo

Research Breakdown

The Examine Research Breakdown has been archived. The Examine team will be incorporating the information in this section throughout the site after a thorough review to ensure it is up to date.

References

Examine Database References

Health Condition/Goal	Health Outcome	Evidence
Multiple Sclerosis	2 outcomes	4 Studies
Type 2 Diabetes	6 outcomes	1 Study
General Cardiovascular Health	1 outcome	1 Study
Dyslipidemia	6 outcomes	3 Studies

Safety InformationNew

Visit Safety Checker Page

Summary
Side Effects
Interactions
Pregnancy & Lactation
Precautions
WADA Status

Safety Summary

Biotin can interfere with multiple commonly used lab tests at doses of 10 mg or higher, leading to results that could be falsely negative or positive.
It is well tolerated with no clearly established side effects or drug interactions.
Biotin supplements seem unlikely to cause harm during pregnancy and lactation, but caution is advised, particularly at high doses.

Side Effects

Biotin is well tolerated and has no identified risk of toxicity with either oral or intravenous use. No established tolerable upper intake level exists.^[4] Studies providing high-dose biotin (300 mg daily) for 6–12 months have generally identified no adverse effects.^[1]

In a case report, an elderly woman taking biotin and pantothenic acid for 2 months developed eosinophilic pleuropericardial effusion (fluid around the heart and lungs).^[43] Additionally, a woman with multiple sclerosis taking high-dose biotin (300 mg daily for 5 months) experienced progressive muscle weakness and showed signs of dysfunctional fatty acid metabolism (when the body can’t break down fats to turn them into energy, and thus they accumulate) which resolved after biotin was discontinued.^[44]

Effect	Details
^[24]	Route: Oral Dose: 300 mg Notes: This side effect was short-lived, and the trial had no control group.
Full safety information is available to Examine Clinician Edition members. Try free for 14 days.

Interactions

Agent	Effect	Level of Evidence	Level of Severity
	Antiseizure medications may reduce biotin levels through the decreased absorption of and increased breakdown and excretion of biotin.^[35]^[36]^[37] Theoretically, this might affect biotin supplementation.	Level of Evidence: Theoretical	Level of Severity: Unknown
Full safety information is available to Examine Clinician Edition members. Try free for 14 days.

Pregnancy and Lactation

Condition	Safety Information
Pregnancy Caution	Biotin is an essential vitamin, and pregnant women may be at an increased risk of biotin deficiency.^[39]^[40] While increased intakes may be advised, the safety of biotin supplements at dosages beyond 300 micrograms (0.3 mg) daily hasn’t been studied.^[41] Biotin seems unlikely to cause harm, but caution is warranted, particularly at high dosages.

Precautions

Precautions for specific demographics, populations, and/or conditions

Population/Condition	Details
	There is some preliminary evidence that cigarette smoking can speed up the metabolism and elimination of biotin, reducing its levels. People who smoke while taking biotin supplements should monitor their biotin levels and consult a healthcare professional to adjust the dose accordingly.^[30]
Full safety information is available to Examine Clinician Edition members. Try free for 14 days.

World Anti-Doping Agency
Not Prohibited

According to the 2026 WADA List of Prohibited Substances, biotin is not prohibited.

Visit Safety Checker Page

Summary
Side Effects
Interactions
Pregnancy & Lactation
Precautions
WADA Status

Safety Summary

Biotin can interfere with multiple commonly used lab tests at doses of 10 mg or higher, leading to results that could be falsely negative or positive.
It is well tolerated with no clearly established side effects or drug interactions.
Biotin supplements seem unlikely to cause harm during pregnancy and lactation, but caution is advised, particularly at high doses.

Side Effects

Effect	Details
^[24]	Route: Oral Dose: 300 mg Notes: This side effect was short-lived, and the trial had no control group.
Full safety information is available to Examine Clinician Edition members. Try free for 14 days.

Interactions

Agent	Effect	Level of Evidence	Level of Severity
	Antiseizure medications may reduce biotin levels through the decreased absorption of and increased breakdown and excretion of biotin.^[35]^[36]^[37] Theoretically, this might affect biotin supplementation.	Level of Evidence: Theoretical	Level of Severity: Unknown
Full safety information is available to Examine Clinician Edition members. Try free for 14 days.

Pregnancy and Lactation

Condition	Safety Information
Pregnancy Caution	Biotin is an essential vitamin, and pregnant women may be at an increased risk of biotin deficiency.^[39]^[40] While increased intakes may be advised, the safety of biotin supplements at dosages beyond 300 micrograms (0.3 mg) daily hasn’t been studied.^[41] Biotin seems unlikely to cause harm, but caution is warranted, particularly at high dosages.

Precautions

Precautions for specific demographics, populations, and/or conditions

Population/Condition	Details
	There is some preliminary evidence that cigarette smoking can speed up the metabolism and elimination of biotin, reducing its levels. People who smoke while taking biotin supplements should monitor their biotin levels and consult a healthcare professional to adjust the dose accordingly.^[30]
Full safety information is available to Examine Clinician Edition members. Try free for 14 days.

World Anti-Doping Agency
Not Prohibited

According to the 2026 WADA List of Prohibited Substances, biotin is not prohibited.

Biotin (Vitamin B7)

Overview

What is biotin?

What are biotin’s main benefits?

What are biotin’s main drawbacks?

How does biotin work?

Dosage InformationMedical disclaimer

Formulations

Range of dosages studies

Other considerations

Supplements Demystified: Get Our Unbiased, Evidence-Based Guide

Examine Database: Biotin (Vitamin B7)

Safety InformationNew

Research FeedRead all studies

Frequently Asked Questions

What are the causes, signs, and symptoms of biotin deficiency?

What are the main dietary sources of biotin?

Does biotin affect hair, nail, or skin health?

Does biotin affect multiple sclerosis?

What are other names for Biotin (Vitamin B7)?

Update History

Safety Information addedmajor

More safety information addedminor

Research Breakdown

References

Examine Database References

Examine Database: Biotin (Vitamin B7)

Safety InformationNew

Table of Contents

Safety Summary

Side Effects

Interactions

Pregnancy and Lactation

Precautions

Precautions for specific demographics, populations, and/or conditions

World Anti-Doping Agency Not Prohibited

Table of Contents

Safety Summary

Side Effects

Interactions

Pregnancy and Lactation

Precautions

Precautions for specific demographics, populations, and/or conditions

World Anti-Doping Agency Not Prohibited

Dosage Information

Safety Information added
major

More safety information added
minor

World Anti-Doping Agency
Not Prohibited

World Anti-Doping Agency
Not Prohibited