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Bio8.5
Biotin Research
Probably helpsModerate safety
21 peer-reviewed studies
What the evidence says
Probably helps
Biotin helped in about half (5/8) of the studies that measured an effect — promising, but not unanimous.
Most evidence is from high-quality meta-analyses and randomised trials published 1989–2026 with a typical study size of 82 participants.
Based on 21 studies · 5 meta-analyses · 12 RCTs · 9,683 total participants
Confidence
High
What the studies found
5helped2unclear1didn't help· 13 more without graded effect data
By outcome
Therapeutic & clinical
Probably helps20 studies
Hair, nails & skin
Mostly mechanism / observational5 studies
Safety profile
Mostly mechanism / observational5 studies
Women's healthProvides essential nutrients for healthy pregnancy · Ongoing
Too few graded studies2 studies
Glucose & metabolic
Too few graded studies1 study
Energy & fatigue
Too few graded studies1 study
Skin healthImproved nail strength and hair quality within 8-12 weeks · 8-12 weeks
Too few graded studies1 study
By the numbers
Pulled from 17 studies with measurable effects
Likely real effects
50%
across studies
People studied
9,683
typical study: 82 people
Strongest designs
17
5 pooled, 12 randomised
Showed benefit
63%
5/8 studies
How long studies ran
1–4 weeks
1
1–3 months
1
3+ months
4
Populations Studied
Progressive multiple sclerosis patients3
Multiple sclerosis patients2
Optic neuritis patients1
Primary progressive multiple sclerosis patients1
Active research area
13 studies in the last 5 years · Latest meta-analysis: 2025
198920072026
1Retinal nerve fiber layer thicknessMeta-Analysisn=2,465 · very large study2025
Although meta-analysis showed no significant effect of vitamins A, B1, B6, B7, B12, and D on several visual parameters, improvements observed in individual studies point to the essential role of vitamin sufficiency in ON.
Gaffney PJ et al. · Multiple sclerosis and related disorders (2025)
No clear effect
← WorseNo effectBetter →
Borderline
The effect of MD1003 (high-dose biotin), vitamin A, and vitamin D on retinal nerve fiber layer (RNFL) thickness from pooled results showed a mean change of 0.15 (SMD 0.15, 95 % CI, -0.33 to 0.64, I2 = 61 %, τ² = 0.11, p = 0.08), which was not significant.
Meta-analysis of visual acuity due to MD1003 and vitamin A from two studies showed a mean change of 0.01 (SMD 0.01, 95 % CI, -0.34 to 0.35, I2 = 0 %, τ² = 0, p = 0.36).
Significant improvements in RNFL thickness due to vitamin A, visual acuity due to vitamins B1, B6, and B12, foveal sensitivity due to vitamins B1, B6, and B12, and the rate of conversion of ON to MS due to vitamin D were observed in individual studies.
2Confirmed disability progression (wCDP%)Meta-AnalysisCited 3×n=3,779 · very large study2023
The results of this study provide the necessary quantitative information for both the rational clinical use of drugs and future clinical trials in primary progressive multiple sclerosis.
Sui Z et al. · Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia (2023)
Huge benefit
← WorseNo effectBetter →
Among these, ocrelizumab showed outstanding performance, with wCDP% of 72.6 at 96 weeks, while the proportions of rest of the drugs ranged between approximately 55-70%.
The results of this study provide the necessary quantitative information for both the rational clinical use of drugs and future clinical trials in primary progressive multiple sclerosis.
3ITW25 improvementMeta-AnalysisCited 16×n=830 · large study2021
A moderate certainty of evidence suggests a potential benefit in favor of HDB administered for 12 to 15 months in terms of ITW25 in patients with PMS.
Espiritu AI et al. · Multiple sclerosis and related disorders (2021)
Huge harm
← WorseNo effectBetter →
Pooled data for ITW25 at 12 to 15 months yielded statistical significance (RR 2.06; 95% CI 1.04-4.09; 2 trials; 796 participants; I2 = 0%) [moderate COE] favoring HDB among patients with PMS.
At 12 to 15 months, no significant differences were found in terms of mean change in EDSS (MD -0.06; 95% CI -0.14-0.02; 2 studies; 796 participants; 889 participants; I2 = 68%) among patients with PMS.
Synthesized data on incidence of any AEs (RR 0.98; 95% CI 0.92-1.04; 3 trials; I2 = 0%) [high COE] and any serious AEs (RR 0.98; 95% CI 0.77-1.24; 3 trials; 889 participants; I2 = 0%) [moderate COE] were not significantly different between HDB and placebo groups.
4Global impression of deteriorationMeta-AnalysisCited 79×n=217 · medium study2020
There are a variety of controlled trials addressing the effects of dietary interventions for MS with substantial variation in active treatment, comparator, and outcomes of interest.
Parks NE et al. · The Cochrane database of systematic reviews (2020)
No clear effect
← WorseNo effectBetter →
Among four trials comparing PUFAs with MUFAs, there may be little to no difference in global impression of deterioration (RR 0.85, 95% CI 0.71 to 1.03; 4 studies, 542 participants; 40% in the PUFA group versus 47% in the MUFA group; low-certainty evidence).
In two trials comparing different PUFAs (omega-3 versus omega-6), there may be little to no difference in relapses (RR 1.02, 95% CI 0.62 to 1.66; 2 studies, 129 participants; 30% in the omega-3 versus 29% in the omega-6 group; low-certainty evidence).
Among three trials comparing omega-3 with omega-6, there may be little to no difference in change in disability progression, measured as mean change in Expanded Disability Status Scale (EDSS) (mean difference (MD) 0.00, 95% CI -0.30 to 0.30; 3 studies, 166 participants; low-certainty evidence).
5Clinical and biological outcomes in multiple sclerosisSystematic ReviewCited 12×n=31 · small study2020
The existing literature provides preliminary support for the use of a number of nutraceutical interventions in MS.
Marx W et al. · Multiple sclerosis and related disorders (2020)
The existing literature provides preliminary support for the use of a number of nutraceutical interventions in MS.
However, sufficiently powered long-term trials are required to expand the currently limited literature and to investigate unexplored nutraceuticals that may target relevant pathways involved in MS such as the gut microbiome and mitochondrial dysfunction.
High quality data on the efficacy of nutritional (vitamins-minerals) supplementations in treating seizures in PWE is scarce; however, designing future clinical trials of polyunsaturated fatty acid supplementation for drug-resistant seizures in adults with focal epilepsy and in children, and also multivitamin supplementations in adults with focal epilepsy seems reasonable and promising.
Asadi-Pooya AA et al. · Clinical nutrition (Edinburgh, Scotland) (2021)
Such clinical trials should be well-designed, randomized, and placebo controlled, with enough sample size and adequate follow-up of 12 months or more.
8Disability progressionRCTCited 89×n=642 · large study2020
This study showed that MD1003 did not significantly improve disability or walking speed in patients with progressive multiple sclerosis and thus, in addition to the potential of MD1003 for deleterious health consequences from interference of laboratory tests, MD1003 cannot be recommended for treatment of progressive multiple sclerosis.
9confirmed disability improvementRCTn=642 · large study2024
This phase 3 RCT provides important definitive evidence on high-dose biotin's efficacy in progressive MS, though the DOI and specific publication details should be verified as the trial timeline makes 2024 publication plausible but uncertain.
Tourbah et al. · Multiple Sclerosis and Related Disorders (2024)
Primary endpoint of confirmed disability improvement was not met in the overall progressive MS population
Subgroup analyses suggested potential benefit in a subset of patients with active progressive disease
High-dose biotin was well tolerated with no new safety signals over extended follow-up
10CLOCK gene expression changesRCTCited 4×n=53 · small study2024
Changing the gut microbiome by probiotic treatment potentially influences CLOCK gene expression.
Kreuzer K et al. · Neuropsychobiology (2024)
Changing the gut microbiome by probiotic treatment potentially influences CLOCK gene expression.
The preliminary results of the PROVIT-CLOCK study indicate a possible interconnection between the gut microbiome and circadian rhythm potentially orchestrated by metabolites.
However, probiotic intervention compared to placebo only differed in microbial diversity profile, not in clinical outcome measures.
Reininghaus EZ et al. · Nutrients (2020)
The elevated abundance of potentially beneficial bacteria after probiotic treatment allows speculations on the functionality of probiotic treatment in depressed individuals.
Furthermore, the finding of upregulated vitamin B6 and B7 synthesis underlines the connection between the quality of diet, gut microbiota and mental health through the regulation of metabolic functions, anti-inflammatory and anti-apoptotic properties.
Concluding, four-week probiotic plus biotin supplementation, in inpatient individuals with a major depressive disorder diagnosis, showed an overall beneficial effect of clinical treatment.
14OGSS reduction in brittle nailsRCTCited 2×n=21 · very small study2019
The combination of HPC-NL and oral biotin is associated with further clinical improvement.
Chiavetta A et al. · Dermatologic therapy (2019)
Huge benefit
← WorseNo effectBetter →
Borderline
The OGSS was significantly reduced during treatments in both groups.
At Month 4, OGSS was reduced by 57% (HPC-NL) and 62% (HPC-NL + B).
At the end of study period, the percentage of subjects with an OGSS reduction of ≥50% in comparison with baseline was 53% in the HPC-NL group and 80% in the HPC-NL + B group (p = .05).
15Biotin metabolism markersRCTCited 25×n=26 · very small study2014
Overall, these data demonstrate significant alterations in markers of biotin metabolism during pregnancy and lactation and suggest that biotin intakes exceeding current recommendations are needed to meet the demands of these reproductive states.
Perry CA et al. · The Journal of nutrition (2014)
Huge benefit
← WorseNo effectBetter →
Likely real
Over the course of the study, pregnant women excreted 69% more (vs. control; P < 0.001) 3-hydroxyisovaleric acid (3-HIA), a metabolite that accumulates during the catabolism of leucine when the activity of biotin-dependent methylcrotonyl-coenzyme A carboxylase is impaired.
Interestingly, urinary excretion of 3-hydroxyisovaleryl-carnitine (3-HIA-carnitine), a downstream metabolite of 3-HIA, was 27% lower (P = 0.05) among pregnant (vs. control) women, a finding that may arise from carnitine inadequacy during gestation.
Lactating women excreted 76% more (vs. control; P = 0.001) of the biotin catabolite bisnorbiotin, indicating that lactation accelerates biotin turnover and loss.
The combination of millet extract, pantothenic acid, L-cystine, and biotin was associated with reduced hair loss, improvements in hair growth and appearance, and high subject satisfaction, and was well tolerated over 12 weeks.
Proksch E et al. · Journal of cosmetic dermatology (2026)
In 112 subjects (mean age 32 ± 1 years; 93.8% female), hair density (n = 109) and the proportion of hairs in the anagen phase increased significantly, while the telogen proportion decreased (p < 0.001, week 12 vs. baseline).
Hair loss had declined by 59% at week 12 (p < 0.001).
Significant improvements in the hairdresser-rated hair quality and appearance parameters (shine, softness/elasticity, strength, smoothness, dryness, vitality, volume) were observed (p < 0.001).
19Glucose management during oral glucose tolerance testRCTCited 41×n=43 · small study2006
This pilot study demonstrates that supplementation with a combination of chromium picolinate and biotin in poorly controlled patients with diabetes receiving antidiabetic therapy improved glucose management and several lipid measurements.
Singer GM et al. · Diabetes technology & therapeutics (2006)
Noticeable benefit
← WorseNo effectBetter →
Likely real
After 4 weeks, there was a significantly greater reduction in the total area under the curve for glucose during the 2-h oral glucose tolerance test for the treatment group (mean change -9.7%) compared with the placebo group (mean change +5.1%, P < 0.03).
This pilot study demonstrates that supplementation with a combination of chromium picolinate and biotin in poorly controlled patients with diabetes receiving antidiabetic therapy improved glucose management and several lipid measurements.