Condition
Hair Growth
Hair growth is the cycle in which follicles in the scalp build new hair, rest, shed it and start again, and it is steered by stem cells and signals within each follicle. Among supplements, TB-500 is the one with reviewed research, and the evidence is very limited: studies found it stimulated follicle stem cells and promoted hair growth in animals. Those studies were small and mostly animal or lab work, so they say little yet about what it might do for people.
Sources: PMID 26083021
- Updated
- How we grade
- 4 studies cited
- Supplements studied
- 0
- Medicines and peptides
- 1
- Graded outcomes
- 1
Prescription medicines and peptides studied, for context
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Hair Growth Stimulates hair follicle stem cells and promotes hair growth in animal models. Induces hair follicle development via Wnt signaling pathway activation. | Improves (the measure goes up) | Small effect | 4 studies | 40 people | ||
What the published studies found
3 automated readings
Biotin (Vitamin B7): 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).
Collagen Peptides: hair growth
The 2 studies read (114 people in all) mostly found an improvement in hair growth. The evidence is limited.
2 studies counted of 7 read: 2 trials (114 people in the trials).
- Randomised trial, 2026; 114 people; women aged 20-50 with cellulite and hair thinning: improves.
Hair diameter also increased significantly at week 24
Low-Molecular-Weight Collagen Peptide Supplementation Improves Cellulite Severity, Skin Elasticity, and Hair Shaft Diameter: A Clinical Study with Pharmacokinetic Evaluation - Randomised trial, 2025; menopausal women: improves.
significantly retarded hair shedding compared to the placebo
Calcium and Vitamin D Supplementation with and Without Collagen on Bone Density and Skin Elasticity in Menopausal Women-A Randomized Controlled Study
- Randomised trial, 2026; 114 people; women aged 20-50 with cellulite and hair thinning: improves.
Zinc: hair growth
The 1 study read (200 people in all) mostly found an improvement in hair growth. The evidence is limited.
1 study counted of 9 read: 1 trial (200 people in the trials).
- Randomised trial, 2003; 200 people; healthy men with androgenetic alopecia: improves. The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial
Key findings
- Hair GrowthImproves (the measure goes up)
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Studies cited
4 studies from PubMed
- Thymosin β(4) and β(10) Expression in Human Organs during Development: A Review.
- Thymosin beta-4 denotes new directions towards developing prosperous anti-aging regenerative therapies
- Thymosin Beta-4 Induces Mouse Hair Growth
- Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications