Biotin

Also known as: vitamin b7, vitamin h, coenzyme r

Grade B — Moderate Evidencevitaminskin-hair
10005000 mcgMorning with food

Biotin (vitamin B7) is a water-soluble B vitamin that serves as a coenzyme for carboxylase enzymes involved in fatty acid synthesis, gluconeogenesis, and amino acid metabolism. While widely marketed for hair, skin, and nail health, evidence for these benefits is primarily limited to those with actual biotin deficiency. An important clinical consideration is that high-dose biotin supplementation (>5mg) can significantly interfere with laboratory assays, causing falsely abnormal thyroid, troponin, and hormone test results.

TL;DR: Water-soluble B vitamin important for fat and carbohydrate metabolism. Commonly used for hair/nail support — evidence is stronger in true deficiency. Important: stop before lab tests.

Last reviewed: 2026-03-12

Quick Facts

Evidence

Grade B

Studies

2

Interactions

2

Forms

1

Evidence Rating: Grade B — Moderate Evidence

Some RCTs with positive results, or strong observational evidence. More research may refine our understanding.

Interaction Warnings

Raw egg whites (avidin)Moderate

Avidin in raw eggs binds biotin and prevents absorption. Avoid raw egg whites when taking biotin.

Alpha-lipoic acidLow

ALA and biotin compete for the same transporter. Separate dosing if taking both.

Important Notes

  • Biotin at doses >1mg can interfere with thyroid, cardiac troponin, and hormone lab tests — stop 48-72h before blood tests
  • True deficiency is rare; most hair loss has other causes
  • Evidence for hair growth in non-deficient individuals is weak

Clinical Evidence (2 studies)

Biotin supplementation for hair and nail fragility

Soleymani T et al. (2017) — Skin Appendage Disord

Biotin improved nail thickness in 91% of patients with brittle nails; hair improvement in documented deficiency states

View on PubMed

High-dose biotin in progressive multiple sclerosis

Sedel F et al. (2015) — Mult Scler Relat Disord

Ultra-high dose biotin (100-300mg) showed neurological improvement in progressive MS pilot trial

View on PubMed

Alternatives to Consider

These supplements target similar goals and may be worth considering alongside or instead of Biotin.

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⚕️ Important Disclaimer

This information is for educational purposes only. It is not medical advice. Always consult a healthcare provider before starting any supplement regimen, especially if you take medications or have health conditions.

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