TB-500 (Thymosin Beta-4)
Injury, Repair & RecoveryPhase 2Also known as: Thymosin Beta-4, TB4, TB 500
TB-500 is a synthetic peptide fragment of thymosin beta-4 (Tbeta4), a 43-amino-acid protein that is one of the most abundant intracellular actin-sequestering molecules in mammalian cells. With a molecular weight of approximately 4963 Da, TB-500 encompasses the active region of thymosin beta-4 responsible for actin binding, cell migration, and wound healing.
Reconstitution Calculator for TB-500 (Thymosin Beta-4)
Pre-filled · 5mg vial · 2500mcg dose
Overview
At A Glance
Actin Sequestration and Cytoskeletal Dynamics…
Overview
TB-500 is a synthetic peptide fragment of thymosin beta-4 (Tbeta4), a 43-amino-acid protein that is one of the most abundant intracellular actin-sequestering molecules in mammalian cells. With a molecular weight of approximately 4963 Da, TB-500 encompasses the active region of thymosin beta-4 responsible for actin binding, cell migration, and wound healing. Thymosin beta-4 was originally isolated from calf thymus tissue and later identified as a ubiquitous cytoplasmic protein expressed in virtually all nucleated cells. The foundational review by Goldstein et al. (2005) established thymosin beta-4 as a multifunctional regenerative peptide with roles spanning wound healing, angiogenesis, anti-inflammation, and cardiac repair. Unlike many bioactive peptides, thymosin beta-4 is not a hormone or cytokine but rather an intracellular actin-regulatory protein that, when released extracellularly following injury, initiates paracrine signaling cascades that drive tissue repair. TB-500 has been studied extensively in preclinical models of cardiac injury. Bock-Marquette et al. (2004) demonstrated that thymosin beta-4 promotes survival of cardiomyocytes after experimental myocardial infarction in mice, reduces infarct size, and improves cardiac function. The mechanism involves activation of the Akt (protein kinase B) survival pathway and migration of cardiac progenitor cells to the injury site. These findings have positioned thymosin beta-4 as a candidate cardiac repair agent, though clinical translation has been limited. In wound healing research, thymosin beta-4 accelerates dermal wound closure by promoting keratinocyte and endothelial cell migration, increasing angiogenesis, and reducing inflammation at the wound site. Philp et al. (2004) showed that topical thymosin beta-4 significantly accelerated full-thickness wound closure in diabetic and aged mouse models. The peptide promotes collagen deposition and extracellular matrix remodeling, resulting in improved scar quality. TB-500 has also shown efficacy in corneal wound healing models. Sosne et al. demonstrated that thymosin beta-4 eye drops accelerate corneal epithelial wound closure and reduce inflammation after chemical or mechanical injury, leading to ophthalmic clinical trials (Phase 2) for neurotrophic keratopathy and dry eye disease. This represents the most advanced clinical development program for any thymosin beta-4-based therapeutic. TB-500 is not FDA-approved for any human therapeutic indication. It is widely used in the equine veterinary space and in the human peptide biohacking community, primarily administered via subcutaneous injection for musculoskeletal recovery, wound healing, and anti-inflammatory effects. The typical reconstitution protocol involves bacteriostatic water, with the lyophilized peptide stored at -20 degrees Celsius and the reconstituted solution refrigerated at 2-8 degrees Celsius. The standard loading protocol in community use involves higher initial doses (typically 2-2.5 mg twice weekly for 4-6 weeks) followed by lower maintenance doses.
Potential Research Fields
Chemical Information
IUPAC Name
Thymosin beta-4 (16–23 fragment)
CAS Number
77591-33-4
Molecular Formula
C212H350N56O78S
Molecular Mass
4963.4 g/mol (acetylated full-length thymosin beta-4; free peptide 4921.4 g/mol)
Amino Acid Sequence
Dosing & Protocols
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Research
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Interactions
Interaction Matrix
Contraindications
Active cancer (theoretical concern with tissue growth promotion). Pregnancy or breastfeeding. Known hypersensitivity to thymosin beta-4 fragments.
Research Disclaimer
This interaction data is compiled from published research and community reports. It may not be exhaustive. Always consult a healthcare professional before combining compounds.
$29.00
up to $89.00
$4.4500
5
9
vial
| Vendor | Product | Form | Qty | Price | $/mg | Coupon | |
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Thymosin Beta-4 5mg | vial | 5mg● In Stock | $39.99BEST | $7.998 | ||
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TB-500 5mg | vial | 1 vial● In Stock | $29.00 | $5.800 | — | |
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TB-500 10mg | vial | 1 vial● In Stock | $49.00 | $4.900 | — | |
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TB-500 20mg | vial | 1 vial● Out of Stock | $89.00 | $4.450 | — | Sign in for stock alert |
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TB-500 5mg | vial | 1 vial● In Stock | $34.99 | $6.998 | — | |
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TB-500 5mg | vial | 1 vial● In Stock | $36.99 | $7.398 | — | |
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TB-500 10mg | vial | 10mg● Out of Stock | $64.20 | $6.420 | Sign in for stock alert | |
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TB-500 5mg | vial | 5mg vial● In Stock | $34.99 | $6.998 | ||
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TB-500 10mg | vial | 10mg vial● In Stock | $49.99 | $4.999 |
Tracking since Mar 13, 2026 · 9 data points
Price History
5 data pointsVendors Selling TB-500 (Thymosin Beta-4)
Ion Peptide
BioMyst Labs
VANDL Labs
ResearchChemHQ
Limitless Biochem EU
How we score these vendors
Every supplier above is graded 0–100 on COA verification, payment transparency, shipping, reviews, and active listings. Methodology published, no pay-to-rank.
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Protocols, calculator & safety for TB-500 (Thymosin Beta-4)
Research Score
1039 PubMed studies
Quality Indicators
Data Completeness
100%COA Verification
6
Verified COAs
1
Vendors w/ COA
High verification rate (100%)
Latest test: 12/5/2024
Research Credibility
Well-researched compound
Quick Facts
Half-Life
Plasma half-life is short - full-length thymosin beta-4 clears on the order of hours, while the short LKKTETQ actin-binding fragment clears within minutes. Tissue-level regenerative effects persist substantially longer than plasma exposure.
Molecular Weight
4963.4 g/mol (acetylated full-length thymosin beta-4; free peptide 4921.4 g/mol)
Administration
Subcutaneous, Intramuscular
CAS Number
77591-33-4
Trial Phase
Phase 2
Safety Profile
Common Side Effects
- • Injection site discomfort (subcutaneous administration)
- • Mild fatigue or lethargy in the days following initial doses
- • Temporary head rush or flushing reported anecdotally
Research Disclaimer
This information is for educational and research purposes only. Not intended as medical advice. Consult a healthcare professional before use.
The Wolverine Stack: BPC-157 + TB-500 Protocol Guide
Complete synergistic recovery protocol — dosing tables, cycling, reconstitution, and 9 PubMed citations.
Frequently Asked Questions
What is TB-500 (Thymosin Beta-4) used for in research?
TB-500 is a synthetic peptide fragment of thymosin beta-4 (Tbeta4), a 43-amino-acid protein that is one of the most abundant intracellular actin-sequestering molecules in mammalian cells. With a molecular weight of approximately 4963 Da, TB-500 encompasses the active region of thymosin beta-4 responsible for actin binding, cell migration, and wound healing. Thymosin beta-4 was originally isolated from calf thymus tissue and later identified as a ubiquitous cytoplasmic protein expressed in virtually all nucleated cells.
The foundational review by Goldstein et al. (2005) established thymosin beta-4 as a multifunctional regenerative peptide with roles spanning wound healing, angiogenesis, anti-inflammation, and cardiac repair. Unlike many bioactive peptides, thymosin beta-4 is not a hormone or cytokine but rather an intracellular actin-regulatory protein that, when released extracellularly following injury, initiates paracrine signaling cascades that drive tissue repair.
TB-500 has been studied extensively in preclinical models of cardiac injury. Bock-Marquette et al. (2004) demonstrated that thymosin beta-4 promotes survival of cardiomyocytes after experimental myocardial infarction in mice, reduces infarct size, and improves cardiac function. The mechanism involves activation of the Akt (protein kinase B) survival pathway and migration of cardiac progenitor cells to the injury site. These findings have positioned thymosin beta-4 as a candidate cardiac repair agent, though clinical translation has been limited.
In wound healing research, thymosin beta-4 accelerates dermal wound closure by promoting keratinocyte and endothelial cell migration, increasing angiogenesis, and reducing inflammation at the wound site. Philp et al. (2004) showed that topical thymosin beta-4 significantly accelerated full-thickness wound closure in diabetic and aged mouse models. The peptide promotes collagen deposition and extracellular matrix remodeling, resulting in improved scar quality.
TB-500 has also shown efficacy in corneal wound healing models. Sosne et al. demonstrated that thymosin beta-4 eye drops accelerate corneal epithelial wound closure and reduce inflammation after chemical or mechanical injury, leading to ophthalmic clinical trials (Phase 2) for neurotrophic keratopathy and dry eye disease. This represents the most advanced clinical development program for any thymosin beta-4-based therapeutic.
TB-500 is not FDA-approved for any human therapeutic indication. It is widely used in the equine veterinary space and in the human peptide biohacking community, primarily administered via subcutaneous injection for musculoskeletal recovery, wound healing, and anti-inflammatory effects. The typical reconstitution protocol involves bacteriostatic water, with the lyophilized peptide stored at -20 degrees Celsius and the reconstituted solution refrigerated at 2-8 degrees Celsius. The standard loading protocol in community use involves higher initial doses (typically 2-2.5 mg twice weekly for 4-6 weeks) followed by lower maintenance doses.
What forms does TB-500 (Thymosin Beta-4) come in?
TB-500 (Thymosin Beta-4) is available in vial form.
How much does TB-500 (Thymosin Beta-4) cost?
Prices start at $29.00 across 5 verified vendors.
How do I compare TB-500 (Thymosin Beta-4) vendors?
Compare prices, payment methods, shipping, and COA scores across 5 vendors.
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