North & North · Peptide Catalog
TB-500
Thymosin Beta-4
Your cells are full of a protein that holds their internal scaffolding together. TB-500 is a synthetic copy of it, the full sequence, nothing trimmed.
The short version
What TB-500 actually is
Its day job inside the cell is holding actin in reserve, ready for the moment a cell needs to move or change shape. What researchers find interesting is what happens after an injury, when the same molecule turns up outside the cell behaving like a signal instead. That double life is why it shows up across so much repair research.
Sold for research purposes only.
The mechanism
How TB-500 Works
One molecule, two jobs. Inside the cell it builds. Outside it, after an injury, it signals.
The first job is well understood. Thymosin Beta-4 grabs loose actin and holds onto it, keeping a reserve the cell can deploy the moment it needs to change shape or move. The second job is stranger and far less settled. After an injury the very same molecule shows up outside the cell, where researchers describe it behaving like a signal rather than a building block. The literature has a good word for this: it calls Thymosin Beta-4 a cytoskeletal protein that moonlights.
Where the science stands
Key Research Areas
- 01
Holding the scaffolding
Cells build their internal skeleton out of actin. The job here is keeping a reserve of it on hand, so a cell can rebuild that skeleton the moment it needs to move or change shape.
- 02
Getting cells to move
Repair only happens if cells travel to the damage. Since actin governs how a cell moves, much of this work asks whether it changes how far and how fast they go.
- 03
Blood supply
Same story as everywhere else in repair: new tissue needs new vessels. Studies isolating the actin binding site look at whether that is where the vessel building starts.
- 04
The heart
The most serious work here is cardiac. A trial starting in 2026 is testing it in people after a heart attack, which is about the hardest repair problem there is.
The evidence
What the Research Actually Did
The big one. A trial beginning May 2026 will test it in 189 people after a heart attack, randomised, double blind, placebo controlled. Heart muscle barely repairs itself, which is what makes this worth watching.
Beijing Northland Biotech. Phase II study in acute myocardial infarction, beginning May 2026. NCT07586865.Put TB-500 and BPC-157 head to head on Achilles tendon healing in July 2026, measuring both how the tissue rebuilt and how strong it ended up.
Effects of BPC-157 and TB-500 on Achilles tendon healing. Jt Dis Relat Surg, July 2026.The American Journal of Sports Medicine took stock in August 2026 of where peptide research actually sits in sports medicine, and what it does and does not yet support.
Peptide Supplements and Their Therapeutic Applications in Sports Medicine. Am J Sports Med, August 2026.
We pulled this together from published work and linked every source, so you never have to take our word for it. Nothing here is a claim about what these compounds do. We would rather you read the sources than trust the summary.
Quality and supply
TB-500 Specifications
- Product contents
- TB-500 10mg lyophilized powder in 3mL vial
- Available size
- 10mg
- Peptide type
- Synthetic 43 amino acid actin sequestering peptide, full length Thymosin Beta-4
- Purity
- >99% Purity · HPLC
- Storage
- Store at 6°C or below, sealed, away from heat, light, and moisture
- Solubility
- Soluble in water
- Fulfillment
- USA domestic fulfillment
- Molecular formula
- C212H350N56O78S
- Molecular weight
- 4963.44 g/mol
- Sequence
- Ac-Ser-Asp-Lys-Pro-Asp-Met-Ala-Glu-Ile-Glu-Lys-Phe-Asp-Lys-Ser-Lys-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-Ile-Glu-Gln-Glu-Lys-Gln-Ala-Gly-Glu-Ser
- CAS number
- 77591-33-4
- PubChem CID
- 16132341
- Synonyms
- Thymosin Beta-4, TB4
- Appearance
- White to off white lyophilized powder
Common questions
Questions People Ask
What is TB-500?
Synthetic Thymosin Beta-4, one of the most abundant peptides in mammalian cells. Research focuses on how cells hold and rebuild their internal scaffolding, and on tissue repair. Sold for research purposes only.
Is this the full sequence or a fragment?
The full 43 amino acid sequence. Some material sold under the TB-500 name is a short fragment of Thymosin Beta-4 instead, and the distinction matters: findings for one do not automatically transfer to the other. The sequence is listed in full in the specifications below.
How is TB-500 different from BPC-157?
They are studied in similar territory but they are not related molecules. TB-500 is a copy of a protein your cells already make in quantity. BPC-157 is a fragment taken from a stomach protein. A 2026 study compared them directly on Achilles tendon healing.
What does >99% purity actually mean?
More than 99% of the vial contents is the peptide itself rather than synthesis byproducts or fragments, verified by HPLC. For a 43 amino acid sequence that is a meaningful figure, since longer chains give synthesis more opportunities to go wrong.
How should it be stored?
Sealed, at 6°C or below, away from heat, light and moisture. It ships as a lyophilized powder, which is the stable form.
Catalog access
Create a Free Account
Create a quick and easy free account to shop TB-500 and other peptides.
Free to create. You will verify your email address before the catalog opens.