
B25018 I By Ajijul Hakim Alif, BPharm, MPharm
Biotin—also known as vitamin B7 or vitamin H—is a water-soluble B vitamin essential for metabolism and cellular energy production. It plays a key role in keratin synthesis, the structural protein that forms hair, skin, and nails. Historically, biotin supplementation was prescribed to treat rare inherited or acquired biotin deficiency, which is associated with hair thinning and alopecia. Recently, biotin has gained popularity in beauty supplements claiming to support hair growth and strength.
What Does Science Say?
Evidence Summary
- Biotin supplementation is beneficial in individuals with biotin deficiency or certain hair disorders caused by genetic or acquired enzyme defects.
- No robust clinical evidence shows that biotin improves hair growth in healthy individuals who already have adequate biotin levels.
Key Studies on Biotin and Hair

Bottom line: Biotin is important for hair health, but supplementation shows measurable benefit only in people with a deficiency, not in healthy individuals.
Natural Sources & How It Works
Biotin is widely available in foods including:
- Egg yolks
- Liver
- Nuts and seeds
- Salmon
- Sweet potatoes
- Spinach and broccoli
The adequate intake (AI) for adults is ~30 µg/day, which is easily achieved with a balanced diet. Biotin functions as a cofactor for carboxylase enzymes involved in fatty acid synthesis, amino acid metabolism, and gluconeogenesis—all critical for cellular energy and keratin production in hair follicles.
Biotin Supplements
Commercially available biotin products include:
- Standalone biotin capsules or tablets (300 µg–10 mg).
- Hair, skin, and nail formulations, often combined with B-complex vitamins, zinc, and herbal extracts.
- Plant-based biotin supplements with silica or collagen. A recent 2025 clinical trial is evaluating plant-based biotin for brittle hair (NCT05972512).
Safety and Side Effects
- Generally safe: Biotin is water-soluble; excess is excreted in urine. No upper intake level has been established.
- Lab test interference: High-dose biotin (>5 mg/day) may alter results of thyroid, cardiac troponin, and other blood tests.
- Mild acne flare: Some anecdotal reports suggest biotin-induced breakouts, possibly due to competition with vitamin B5.
- At-risk groups: Patients with gastrointestinal disorders, those on anticonvulsants, or post-bariatric surgery patients may need supplementation due to reduced absorption.
Conclusion
- Who benefits? Individuals with documented biotin deficiency or rare metabolic disorders.
- Who doesn’t need extra? Healthy individuals who meet their daily biotin needs through diet.
- What to do:
- Suspect a deficiency? Get tested before starting supplements.
- If deficient, use modest doses (micrograms to low milligrams).
- Avoid mega-doses (>5 mg/day) unless medically indicated.
- Focus on balanced nutrition, proper scalp care, and evidence-based hair loss treatments such as minoxidil or finasteride.
References
- Patel DP, Swink SM, Castelo-Soccio L. A Review of the Use of Biotin for Hair Loss. Skin Appendage Disord. 2017;3(3):166–169. https://pubmed.ncbi.nlm.nih.gov/28879195/
- Pawlowski J, et al. Effect of biotin on hair roots and sebum excretion in women with diffuse alopecia. Hautarzt. 1966;17:155–158. https://pubmed.ncbi.nlm.nih.gov/4223823/
- Yelich J, et al. Biotin for Hair Loss: Teasing Out the Evidence. J Clin Aesthet Dermatol. 2024. https://jcadonline.com/biotin-for-hair-loss-evidence/
- Sen P, et al. Hair Loss After Sleeve Gastrectomy and Effect of Biotin Supplements. Obes Surg. 2021;31(8):3701–3708. https://pubmed.ncbi.nlm.nih.gov/32762597/
- Aksac A, et al. Evaluation of biophysical skin parameters and hair changes in patients with acne vulgaris treated with isotretinoin and the effect of biotin use on these parameters. Skin Res Technol. 2021;27(5):753–760. https://pubmed.ncbi.nlm.nih.gov/33682085/
- Trüeb RM. Serum Biotin Levels in Women Complaining of Hair Loss. Int J Trichology. 2016;8(2):73–77. https://pubmed.ncbi.nlm.nih.gov/27601860/
- Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatol Ther (Heidelb). 2018;8(1):51–70. https://link.springer.com/article/10.1007/s13555-018-0278-6
- ClinicalTrials.gov. Plant-Based Biotin Clinical Trial (2025). NCT05972512. https://www.centerwatch.com/clinical-trials/listings/NCT05972512/
Acknowledgment:
We used ChatGPT by OpenAI to refine grammar and improve readability.
Note:
This content is for informational purposes only and is not intended as medical advice. Always consult your healthcare provider before starting any supplement.
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