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Tissue-repair research

TB-500 Research: What Studies Have Investigated About Thymosin Beta-4

TB-500 research is largely the research on thymosin β4 — and it is overwhelmingly preclinical. This page summarises what TB-500 is, how it relates to endogenous thymosin β4, the mechanisms researchers have examined, and the animal and in-vitro models in the literature — cited neutrally, framed as “studies investigated,” with no benefit claims.

RESEARCH USE ONLY. Cellworks supplies compounds strictly for in-vitro laboratory research. Nothing on this page is a medical, efficacy, or dosing claim, and no product is for human or veterinary use.
Reviewed by Jason Fleming — Biochemistry consultant, Nanyang Technological University, Singapore.Last reviewed: 2026-07-12

What is TB-500?

What is TB-500? It is a synthetic peptide corresponding to the actin-binding region of thymosin β4 (Tβ4), a naturally occurring 43-amino-acid peptide found widely in mammalian cells. The common point of confusion is the naming: “TB-500” is a research-catalogue name, whereas thymosin β4 is the endogenous molecule. Some material catalogued as TB-500 corresponds to the full Tβ4 sequence, and some to a fragment of it — so the label describes research-grade material rather than a single distinct biomolecule.

Held to a neutral definition, then, TB-500 is bench material based on the thymosin-β4 sequence, supplied for laboratory study. Stating the relationship this way matters because most of the literature a reader will encounter is written about Tβ4, and it is that body of work — not a separate “TB-500” literature — that the sections below summarise.

Molecule properties

Thymosin β4 belongs to the β-thymosin family of small, highly conserved peptides — around 5 kDa and intrinsically disordered in isolation, which is typical of this class. In research catalogues the material is supplied as a lyophilized (freeze-dried) powder, its stable form, and is characterised in that state. These are molecule facts: sequence family, size, physical form.

Because the peptide is small and its sequence defined, analytical methods can confirm it precisely — HPLC for purity and mass spectrometry for identity — which is why a per-batch Certificate of Analysis is meaningful for this molecule. Everything here is a molecule and handling property; none of it is a reconstitution-for-use instruction or an implication of any use.

Mechanisms researchers have examined

The thymosin-β4 literature is pleiotropic: multiple pathways have been examined, and no single validated human mechanism is established. The recurring research directions are:

Actin sequestration

Tβ4 is described as the principal G-actin–sequestering peptide in mammalian cells. Studies report that it binds monomeric (G-)actin and buffers the free-monomer pool, with a higher affinity for ATP-actin than ADP-actin, so that the ATP/ADP ratio modulates the interaction (Carlier et al., 1993). Structural work established how a WH2-type motif mediates this sequestration (Irobi et al., 2004; Xue et al., 2014). This actin-buffering role is the most firmly characterised biochemistry of the molecule.

Cell migration & angiogenesis (in models)

Laboratory work examined endothelial-cell migration and angiogenic readouts: Malinda et al. (1997) reported that Tβ4 stimulated directional migration of human umbilical-vein endothelial cells, and Grant et al. (2003) reported that the actin-binding site itself was tied to angiogenic activity in their assays. A 2007 review in Angiogenesis surveyed these modes of action. These are model-system observations, not human outcomes.

The Ac-SDKP N-terminal fragment

The N-terminal tetrapeptide of Tβ4, acetyl-Ser-Asp-Lys-Pro (Ac-SDKP), is studied separately for cell-cycle and anti-fibrotic signalling in model systems. It is worth naming because researchers examine it as a distinct fragment with its own literature rather than assuming it behaves identically to the parent peptide.

Taken together, the field describes Tβ4 as acting through several pathways rather than one defined receptor. Each direction above names what studies looked at in models — not an effect, a benefit, or a result a reader should expect.

Research models in the literature

The evidence base is predominantly preclinical. Reported model systems include rodent dermal and full-thickness wound models (a 2016 dermal-healing study, PMID 27450738); rodent and rabbit cardiac-injury models in which Bock-Marquette et al. (2004) examined Tβ4 and integrin-linked kinase; and ophthalmic and corneal-surface models in the work of Sosne and colleagues, which formed the basis for the RGN-259 clinical candidate — the trial status of which is noted here only as status, with no outcome claim.

A 2026 scoping review of thymosin β4 and TB-500 in tissue healing surveys this landscape as a whole. The honest summary, stated plainly and more than once: most evidence is preclinical — animal and in-vitro — and human clinical data is limited and largely confined to specific ophthalmic candidates. There is no efficacy verdict to draw from this literature, and none is offered.

TB-500 in the tissue-repair research group

In research catalogues, TB-500 is usually grouped with other peptides studied in tissue-repair contexts, most often BPC-157, and it appears within the multi-peptide Wolverine research blend. The only comparison drawn here is one of research focus — which questions each molecule’s literature has examined — because the published work studies them independently. For BPC-157’s own literature, see BPC-157 research: mechanism & studies; the blend context is on the Wolverine research explainer. Nothing here is stacking, combination, or protocol guidance.

Research-grade sourcing & verification

For laboratory research use only, TB-500 is supplied with a per-batch Certificate of Analysis reporting HPLC purity (%), mass-spec identity confirmation, and lot traceability. The batch received can be checked directly on the self-serve verify tool, and how to read a COA explains what each line on the certificate means.

TB-500 10 mg

Verify a batch

Every order ships with a per-batch Certificate of Analysis. Have a vial in hand? Enter its lot number to look up the COA for that exact batch.

Frequently asked questions

Is TB-500 the same as thymosin beta-4?
They are closely related but not identical as terms. Thymosin beta-4 (Tβ4) is the naturally occurring 43-amino-acid peptide; "TB-500" is a research-catalogue name for synthetic material based on it. Some catalogued TB-500 corresponds to the full Tβ4 sequence and some to a fragment of it. The name is a research label, not a distinct endogenous molecule.
What does thymosin beta-4 do in cells?
At the cell-biology level, thymosin beta-4 is described as the principal G-actin–sequestering peptide in mammalian cells: it binds monomeric (G-)actin and buffers the monomer pool (Carlier et al., 1993; Irobi et al., 2004). This is a description of an examined cellular role, not a human-benefit claim.
Has TB-500 / thymosin beta-4 been studied in humans?
Most published research is preclinical — cell cultures and animal models. Limited human trials exist only for specific candidate formulations, most notably ophthalmic candidates such as RGN-259. No efficacy claim is made here.
What is the difference between TB-500 and BPC-157 in the research?
They are distinct molecules with separate research lineages: TB-500 traces to the actin-sequestration biology of thymosin beta-4, while BPC-157 is a pentadecapeptide of gastric-protein origin. The only comparison made here is one of research focus; nothing on this page is stacking or combination guidance.
What is the Ac-SDKP fragment?
Ac-SDKP is the N-terminal tetrapeptide of thymosin beta-4 — acetyl-Ser-Asp-Lys-Pro. It is studied separately in cell-cycle and anti-fibrotic signalling models as a distinct fragment.

Literature cited

  1. Carlier MF, Jean C, Rieger KJ, Lenfant M, Pantaloni D. “Modulation of the interaction between G-actin and thymosin β4 by the ATP/ADP ratio.” PNAS. 1993;90(11):5034–5038.
  2. Irobi E, Aguda AH, Larsson M, et al. “Structural basis of actin sequestration by thymosin-β4: implications for WH2 proteins.” EMBO J. 2004;23(18):3599–3608.
  3. Xue B, Leyrat C, Grimes JM, Robinson RC. “Structural basis of thymosin-β4/profilin exchange leading to actin filament polymerization.” PNAS. 2014;111(43):E4596–E4605.
  4. Malinda KM, Goldstein AL, Kleinman HK. “Thymosin β4 stimulates directional migration of human umbilical vein endothelial cells.” FASEB J. 1997;11(6):474–481.
  5. Grant DS, et al. “The actin binding site on thymosin β4 promotes angiogenesis.” FASEB J. 2003.
  6. Bock-Marquette I, Saxena A, White MD, Dimaio JM, Srivastava D. “Thymosin β4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair.” Nature. 2004;432(7016):466–472.
  7. “Thymosin β4 and angiogenesis: modes of action and therapeutic potential.” Angiogenesis. 2007 (review).
  8. “Thymosin β4 promotes dermal healing.” Preclinical rodent wound-model study, 2016 (PMID 27450738).
  9. Sosne G, et al. “Primary mechanisms of thymosin β4 repair activity in dry eye disorders and other tissue injuries.” IOVS — basis for the RGN-259 candidate (trial status only).
  10. “Thymosin beta-4 and TB-500 in tissue healing, regeneration, and musculoskeletal repair: a scoping review.” Applied Sciences. 2026.

RESEARCH USE ONLY — NOT FOR HUMAN CONSUMPTION. All products are sold strictly for in-vitro laboratory research and are not intended for human or veterinary use, ingestion, or administration. Nothing on this page is a medical or efficacy claim. You must be 21 or older to browse this catalog.