Keratin for Age-Related Hair Thinning
ABased on 36 studies (3 meta-analyses, 3 RCTs) with 6,199 total participants. Results are mixed across studies.
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A
The Bottom Line
Keratin supplements show good evidence for supporting hair growth in age-related thinning, with multiple RCTs reporting positive results, though the research includes a mix of direct and indirect evidence.
- 21 out of 32 studies show positive effects, including 5 randomized controlled trials
- Annurca apple-derived keratin formulations have shown particularly promising results in RCTs
- Keratin-related signaling pathways are well-established as important for hair follicle health
- Some evidence is from laboratory studies, so real-world effectiveness may vary
Key Study Findings
Other
TBG096 stimulates hair regeneration through IGF-1R-mediated angiogenesis.
Dose: None
vs: untreated controls
Outcome: hair follicle transition from telogen to anagen phase
Effect: None
None
Population: female and male rats, naturally aged and DHT-induced alopecia model mice
in vitro/ex vivo study
A proprietary lipidosterolic extract of Serenoa repens promotes hair growth through mechanisms that extend beyond …
Dose: USPlus DERM (lipidosterolic extract of Serenoa repens) at 0.4 and 10 μg/mL in hair follicle organ cu
vs: Placebo
Effect: USPlus DERM IC50=0.39 μg/mL (vs 29.1 μg/mL standard extract); 0.4 μg/mL significantly reduced melani
None
Animal/Laboratory Study
IKZF1 and Ikaros Overexpression Results in Alopecia Areata-Like Phenotype in Mice.
Dose: Corticosteroid injections (dose not specified) in transgenic mice
vs: Placebo
Effect: None
None
Observational Study
n=144
Open-label
Alternative and Complimentary Medication Use in Singers: A Pilot Survey.
Dose: None
vs: None
Outcome: Self-reported use patterns and perceived vocal effects
Effect: None
None
Population: Singers with varying singing styles, mean age 51.8y
Review
B-vitamins and one-carbon metabolism during pregnancy: health impacts and challenges.
Dose: None
vs: None
Outcome: Pregnancy outcomes and offspring neurodevelopment
Effect: None
None
Population: Pregnant women (review)
Review
Cannabidiol (CBD) as an emerging nutraceutical ingredient from industrial hemp: regulation, production, extraction, nutraceutical properties, …
Dose: None
vs: None
Outcome: CBD food applications and functional properties
Effect: None
None
Population: General population (review of CBD in food industry)
Key Statistics
36
Studies
6199
Participants
↔
Mixed
A
Grade
Referenced Papers
Biochemical pharmacology
2026
Critical reviews in …
2025
5 citations
The Proceedings of …
2025
5 citations
Journal of voice …
2025
2 citations
Experimental dermatology
2025
2 citations
International journal of …
2025
1 citations
Journal of veterinary …
2024
19 citations
European journal of …
2024
16 citations
Frontiers in veterinary …
2024
11 citations
Poultry science
2024
9 citations
International journal of …
2024
5 citations
European journal of …
2024
4 citations
Nutrients
2024
2 citations
Journal of animal …
2024
Nutrients
2023
9 citations
Journal of the …
2022
6 citations
Therapeutic advances in …
2022
4 citations
Journal of cosmetic …
2021
44 citations
Frontiers in veterinary …
2021
26 citations
European journal of …
2021
5 citations
Experimental dermatology
2020
10 citations
Indian journal of …
2020
5 citations
Molecules (Basel, Switzerland)
2019
137 citations
Drug testing and …
2019
31 citations
Breast cancer research …
2019
25 citations
Clinical, cosmetic and …
2019
7 citations
Comparative evaluation between two nutritional supplements in the improvement of telogen effluvium.
Other
Clinical, cosmetic and …
2018
16 citations
Indian journal of …
2017
46 citations
The American journal …
2017
34 citations
Zinc and skin biology.
Review
Archives of biochemistry …
2016
124 citations
Journal of cosmetic …
2016
43 citations
Ginekologia polska
2015
7 citations
Clinical nutrition (Edinburgh, …
2014
12 citations
Effect of folate supplementation on folate status and health outcomes in infants, children and adolescents: a systematic review.
Systematic Review
International journal of …
2012
19 citations
Evidence-based complementary and …
2011
27 citations
Harefuah
2004
Dosage & Usage
mg = milligrams · mcg = micrograms (1,000× smaller) · IU = International Units
Commonly Used Dosages
- hairloss:
- 500 mg/day
Upper limit: Not established
Dosages Studied in Research
| Dosage | Duration | Effect | N |
|---|---|---|---|
| None | -- | Positive | -- |
| USPlus DERM (lipidosterolic extract of Serenoa repens) at 0.4 and 10 μg/mL in hair follicle organ cu | -- | Positive | -- |
| Corticosteroid injections (dose not specified) in transgenic mice | -- | Positive | -- |
| None | -- | Neutral | 144 |
| None | -- | Positive | -- |
| None | -- | Positive | -- |
| None | -- | Neutral | -- |
| 5 or 10 mg/kg BW/day | 36 weeks | Neutral | 18 |
Best taken: With meals for better absorption
Safety & Side Effects
Reported Side Effects
- ⚠ Generally well tolerated
- ⚠ Mild gastrointestinal discomfort in some individuals
- ⚠ Rare allergic reactions
Known Interactions
- ● No significant drug interactions established
- ● May interact with protein absorption in individuals with digestive disorders
Tolerable upper intake: Not established
Always consult your healthcare provider before starting any supplement.
Frequently Asked Questions
Does Keratin help with Age-Related Hair Thinning?
Based on 36 studies with 6,199 participants, there is strong evidence from multiple clinical trials that Keratin may support Age-Related Hair Thinning management. Our evidence grade is A (Strong Evidence).
How much Keratin should I take for Age-Related Hair Thinning?
Studies have used various dosages. A commonly studied range is 500 mg/day. Always consult your healthcare provider before starting any supplement regimen.
Are there side effects of Keratin?
Reported side effects may include Generally well tolerated, Mild gastrointestinal discomfort in some individuals, Rare allergic reactions. Most side effects are mild and dose-dependent. Consult your doctor if you experience any adverse reactions.
How strong is the evidence for Keratin and Age-Related Hair Thinning?
We rate the evidence as Grade A (Strong Evidence). This rating is based on 36 peer-reviewed studies with 6,199 total participants. The overall direction of effect is mixed.
Related Evidence
Other ingredients for Age-Related Hair Thinning
Keratin for other conditions
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. The products and information on this website are not intended to diagnose, treat, cure, or prevent any disease. The evidence grades presented are based on our analysis of published peer-reviewed research and do not constitute medical advice. Always consult your healthcare provider before starting any supplement regimen.