TB-500 (Ac-LKKTETQ)
Also known as: TB-500, Ac-LKKTETQ, Thymosin Beta-4 Fragment 17-23, Fequesetide
Thymosin Beta-4 Active Fragment | Healing Peptide
Overview
TB-500 (Ac-LKKTETQ) is a synthetic derivative of thymosin beta-4 consisting of the N-terminal acetylated 17-23 amino acid fragment. This sequence represents the active site within thymosin beta-4 responsible for actin binding, cell migration, and wound healing. Research shows it promotes endothelial cell differentiation, angiogenesis, keratinocyte migration, collagen deposition, and decreases inflammation. The acetylation protects against N-terminal degradation while maintaining biological activity.
Key benefits
- Promotes wound healing
- Enhances cell migration
- Supports angiogenesis (new blood vessel formation)
- Reduces inflammation
- Promotes keratinocyte migration
- Supports collagen deposition
- Enhances tissue repair
- Active region of thymosin beta-4
Mechanism of action
TB-500 contains the LKKTETQ sequence which is the actin-binding motif of full-length thymosin beta-4. This fragment shares many properties of the parent protein regarding cell proliferation, differentiation, and migration. It promotes angiogenesis by upregulating VEGF expression and enhancing endothelial cell sprouting. The peptide undergoes serial cleavage at the C-terminus during metabolism, while the N-terminal acetylation provides protection from degradation.
Molecular data
- Type
- Acetylated heptapeptide
- Half-life
- Not precisely established; effects persist longer than 24 hours
Sequence
Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln
Indications
What the research community uses this compound for, with self-reported effectiveness.
Tissue Repair
Vascular Support
Anti-Inflammatory
Dosing protocols
Common protocols by delivery method. Adjust the curve below to model accumulation in your own cycle.
Delivery method
| Protocol | Dose | Frequency | Duration |
|---|---|---|---|
| — | 2-2.5 mg | 2x weekly for 4-6 weeks | — |
| — | 2 mg | Weekly or bi-weekly | — |
Safety
Reported adverse effects, contraindications, and what to monitor on cycle.
Common side effects
- Injection site reactions
- Mild fatigue
- Head rush (reported)
Rare side effects
- Allergic reactions
- Unknown long-term effects
Contraindications
- Not authorized for medicinal use
- Active cancer (theoretical concern)
- Pregnancy or breastfeeding
- Prohibited by WADA in sports
Monitoring
- Research peptide - medical supervision recommended
- Banned substance in competitive sports