Peptide class
Peptides derived from or structurally related to thymosin proteins — naturally occurring compounds with established roles in immune function, actin cytoskeletal regulation, and tissue repair.
| Compound | Mechanism | Primary reported use | Profile |
|---|---|---|---|
| TB-500 (Thymosin Beta-4 fragment) | Actin sequestration via Tβ4 17–23 sequence; promotes cell migration and anti-inflammation | Connective tissue repair, wound healing, systemic recovery | View profile |
| Thymosin Alpha-1 (Tα1) | T-cell maturation and immune system modulation; TLR signalling | Immune support, antiviral, oncology support research | Coming soon |
TB-500 is the synthetic peptide corresponding to the 17–23 amino acid sequence of Thymosin Beta-4 (Tβ4), a naturally occurring actin-binding protein found in most mammalian cells. The key biological activity of this sequence is actin monomer sequestration — binding G-actin (globular, monomeric actin) and preventing its polymerisation into F-actin (filamentous actin). This regulation of actin dynamics affects cell motility, migration, and cytoskeletal remodelling, particularly relevant to the migration of keratinocytes, endothelial cells, and macrophages required for wound healing.
Thymosin Alpha-1 has a fundamentally different mechanism from TB-500. It is an immunomodulatory peptide that acts on innate and adaptive immune pathways — specifically, it is reported to activate toll-like receptors (TLR) and dendritic cells, enhance T-cell differentiation, and upregulate natural killer (NK) cell activity. The two thymosin peptides share a name due to historical classification from thymus extracts but differ substantially in mechanism, targets, and research applications.
Both thymosin peptides have documented anti-inflammatory properties, though via different mechanisms. TB-500 reduces pro-inflammatory cytokines and modulates NF-κB signalling; Thymosin Alpha-1 reduces inflammatory cytokine profiles while enhancing adaptive immune responses. TB-500 additionally promotes angiogenesis — new blood vessel formation — through upregulation of vascular endothelial growth factor (VEGF) and related pathways, making it functionally similar to BPC-157 in some tissue repair contexts while differing in the upstream mechanism.
Thymosin Beta-4 was first isolated from thymus tissue in the 1960s and characterised as an actin-sequestering protein. TB-500 (the 17–23 fragment) emerged as the biologically active research sequence following identification of the actin-binding domain. Human clinical trials with Thymosin Beta-4 have investigated cardiac repair and corneal wound healing.
Thymosin Alpha-1 (Tα1, thymalfasin) has a more extensive clinical record — it is approved in some countries as Zadaxin for hepatitis B, hepatitis C, and as an adjuvant in cancer immunotherapy. Research has investigated it for its potential role in immune reconstitution in immunocompromised patients and as an adjuvant to vaccination.
TB-500
Commonly researched for tendon, ligament, and muscle injury recovery, and as a systemic tissue repair agent. Commonly reported doses range from 2.5 to 10 mg per week, typically via SubQ or IM injection. Often combined with BPC-157 in the Wolverine stack, leveraging complementary mechanisms (angiogenesis via different upstream pathways).
Thymosin Alpha-1
An immunomodulatory peptide with approved pharmaceutical applications in some jurisdictions. Research has investigated its potential role in viral infection, cancer immunotherapy adjuvant use, and immune reconstitution. Distinct in mechanism and application from TB-500 despite the shared class name.