About TB4-Frag
Active fragment of Thymosin Beta-4; promotes actin dynamics and cell migration; activates hair follicle stem cells; modulates inflammatory signaling
TB-4 Fragment (Thymosin Beta-4 17-23) is a short synthetic peptide derived from the thymosin beta-4 protein, investigated for wound healing, skin repair, and hair follicle regeneration. Thymosin beta-4 facilitates actin sequestration, keratinocyte migration, and stem cell recruitment to sites of tissue injury; the 17-23 fragment retains portions of these bioactive properties. Peer-reviewed studies demonstrate that thymosin beta-4 promotes hair follicle stem cell activation and dermal tissue regeneration in preclinical models, providing a mechanistic basis for skin-related applications. TB-4 Fragment is an investigational peptide with limited human clinical data and is not approved by the FDA for any therapeutic use. TB4-Frag vs full-length thymosin beta-4 TB-4 Fragment (residues 17–23 of thymosin beta-4, sequence: Leu-Lys-Lys-Thr-Glu-Thr-Gln) is a distinct, smaller molecule compared to full-length thymosin beta-4 (43 amino acids). The fragment retains the actin-binding motif that drives keratinocyte migration and stem cell recruitment — mechanisms central to the wound healing and hair follicle regeneration research attributed to TB4 — but lacks the full protein's Ac-SDKP-generating and anti-fibrotic properties. The lower molecular weight of the fragment (approximately 870 Da vs ~4,900 Da for full Tb4) is proposed to improve transdermal penetration for topical applications, making TB4-Frag relevant to cosmetic skin and scalp formulations where injectable administration is not used. In the research peptide market, TB4-Frag is positioned as a topical active for skin repair and hair density contexts; full-length thymosin beta-4 (sold as TB-500) is used for systemic/injectable recovery and tissue repair applications. The two should not be conflated — they have different sequences, molecular weights, and proposed application contexts despite sharing a mechanistic origin.
TB4-Frag Benefits & Research Areas
Research Signals
Population research notes
These signals reflect research interest areas, not treatment indications.
Regulatory & Evidence
Risk Profile
Generally considered lower risk in research contexts. Risk profile varies by individual — review contraindications before use.
Regulatory Status
- Availability Status
- Research Only
- FDA Status
- Not Evaluated
N-terminal TB-4 fragment (Ac-SDKP tetrapeptide). Distinct from full-length TB-500/Thymosin Beta-4 (Category 2). No separate FDA action on this fragment. Anti-fibrotic research use only.
Regulatory status reflects publicly available information and may change. This is not legal or medical advice.
Research Sources
2 sources cited · 2 moderate
2 Animals
Role of thymosin beta 4 in hair growth
Molecular Genetics and Genomics · 2016
Research in thymosin beta 4 (Tβ4) transgenic overexpressing and global knockout mouse models found that Tβ4 promotes hair shaft formation and follicle regeneration via the Wnt/β-catenin/Lef-1 signaling pathway, upregulating MMP-2 and VEGF; knockout mice showed dramatically reduced expression of these markers, establishing the molecular mechanism relevant to TB4 fragment's hair growth-promoting activity.
Thymosin beta 4 induces hair growth via stem cell migration and differentiation
Annals of the New York Academy of Sciences · 2007
Research in multiple rat and mouse models including a thymosin beta 4 transgenic overexpressing line found that Tβ4 promotes hair growth by stimulating follicle stem cell migration, differentiation, and protease production; these findings provide direct mechanistic evidence for the hair growth-promoting activity of the TB4 fragment peptide derived from thymosin beta 4.
TB4-Frag Side Effects & Safety Considerations
Generally considered lower risk in research contexts. Individual response varies — review all considerations before use.
Reported contraindications & considerations
Consult a qualified healthcare professional before making any health decisions. This information is educational only and does not constitute medical advice.
Where to Buy TB4-Frag — Providers & Availability
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Questions to Ask Your Provider
Frequently Asked Questions — TB4-Frag
TB-4 Fragment (Thymosin Beta-4 17-23) is a short synthetic peptide derived from the thymosin beta-4 protein, investigated for wound healing, skin repair, and hair follicle regeneration. Thymosin beta-4 facilitates actin sequestration, keratinocyte migration, and stem cell recruitment to sites of tissue injury; the 17-23 fragment retains portions of these bioactive properties.
hair growth, wound healing, anti-inflammatory, tissue repair.
Research on TB4-Frag primarily documents effects related to hair growth and wound healing and anti-inflammatory and tissue repair. These are areas covered in preclinical and clinical literature — individual response varies and effects depend on context of use.
Reported contraindications and considerations for TB4-Frag include none well-established. This is educational information only — consult a qualified healthcare professional before use.
11 providers in the directory currently offer TB4-Frag.
Research in thymosin beta 4 (Tβ4) transgenic overexpressing and global knockout mouse models found that Tβ4 promotes hair shaft formation and follicle regeneration via the Wnt/β-catenin/Lef-1 signaling pathway, upregulating MMP-2 and VEGF; knockout mice showed dramatically reduced expression of these markers, establishing the molecular mechanism relevant to TB4 fragment's hair growth-promoting activity.