Supplement
Biotin is a B vitamin the body uses to make keratin, the protein in hair, skin and nails, and to turn food into energy. People mostly look at it for nail health, where the evidence is moderate, but the trial results available here come from progressive multiple sclerosis, where symptoms showed no clear difference. That evidence is very limited, covering four studies and 360 people, so it says little about nails.
Sources: PMID 33222767; PMID 27589059
- Updated
- How we grade
- 7 studies cited
- Best evidence
- Grade D
- Conditions studied
- 3
- Outcomes
- 3
- Graded outcomes
- 0003
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Multiple Sclerosis Symptoms No effect | NoneNo effect | 4 studies | 360 people | |||
Studies that measured multiple sclerosis symptoms
| ||||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Blood glucose No effect | NoneNo effect | 1 study | 33 people | |||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Blood glucose No effect | NoneNo effect | 1 study | 33 people | |||
What the published studies found
1 automated reading
Hair growth
The best available review (2024, 3 studies) found little or no difference in hair growth. That review studied people with hair loss. 1 of the 3 studies read agree; 2 found an improvement. The evidence is limited.
3 studies counted of 8 read: 2 reviews and 1 trial (97 people in the trials).
- Systematic review, 2024; 3 studies; people with hair loss: no clear difference (the review the verdict rests on).
no difference between the biotin and placebo groups for hair growth
Biotin for Hair Loss: Teasing Out the Evidence - Systematic review, 2017; 18 studies, 18 people; patients with underlying pathology for poor hair growth: improves. A Review of the Use of Biotin for Hair Loss
- Randomised trial, 2025; 97 people: improves. The Role of Sesbania grandiflora-Derived Biotin and Bambusa arundinacea-Derived Silica Extracts in Promoting Hair, Skin, and Nail Health: A Randomized, Double-Blind, Placebo-Controlled Clinical Study
- Systematic review, 2024; 3 studies; people with hair loss: no clear difference (the review the verdict rests on).
Key findings
- Multiple Sclerosis Symptoms
- Blood glucose
Shop Biotin (Vitamin B7)
Third-party tested Biotin (Vitamin B7) products. The evidence above is limited, so read it before you buy.
- Grade D
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Studies cited
7 studies from PubMed
- Biotin supplementation reduces plasma triacylglycerol and VLDL in type 2 diabetic patients and in nondiabetic subjects with hypertriglyceridemia
- Safety and efficacy of MD1003 (high-dose biotin) in patients with progressive multiple sclerosis (SPI2): a randomised, double-blind, placebo-controlled, phase 3 trial
- MD1003 (high-dose biotin) for the treatment of progressive multiple sclerosis: A randomised, double-blind, placebo-controlled study.
- High doses of biotin in chronic progressive multiple sclerosis: a pilot study.
- MD1003 (High-Dose Pharmaceutical-Grade Biotin) for the Treatment of Chronic Visual Loss Related to Optic Neuritis in Multiple Sclerosis: A Randomized, Double-Blind, Placebo-Controlled Study.
- Effects of biotin on lipids and other constituents of plasma of healthy men and women
- Treatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopy