TB-500 vs thymosin beta-4: are they the same?
Research context reviewed 5 October 2026Not necessarily. Thymosin beta-4 is a 43-amino-acid peptide. In a 2012 laboratory analysis, material sold as TB-500 contained a much shorter, seven-amino-acid segment called Ac-LKKTETQ. The name alone does not establish which molecule is in a supplier's vial.
| Name on the source | Sequence shown | What that source establishes |
|---|---|---|
| Thymosin beta-4 in the literature | 43 amino acids | The full peptide studied in many thymosin beta-4 papers. |
| Material sold as TB-500 in the 2012 analysis | 7 amino acids | The identity of the material analysed in that paper, not every TB-500 vial. |
| PEPTALIAS-linked supplier PDF | 47 amino acids | A printed reference-template sequence, not confirmed identity of a current vial. |
Why does the shorter segment matter?
Researchers have investigated thymosin beta-4 for cell movement during tissue repair. In an aged-mouse study, the full peptide increased skin-cell movement into wounds, contraction of the wound and collagen deposition. A synthetic seven-amino-acid piece containing its actin-binding region also promoted repair in those mice.
That is a concrete finding in mice, not a licence to transfer every result for full-length thymosin beta-4 to an unspecified TB-500 product.
What does PEPTALIAS show for TB-500?
The PEPTALIAS listing calls it a synthetic thymosin-related peptide. The linked PDF uses a different sequence from both literature examples in the table and labels itself a reference template for customer consultation. It does not establish the sequence of a current PEPTALIAS vial.
If sequence is important to your work, ask PEPTALIAS for the current material's sequence, expected and measured mass, and batch reference before deciding. How to read a peptide COA shows where those details belong.
PEPTALIAS also lists TB-500 alone, BPC-157 + TB-500 and KLOW. Compare the named components and amounts, but do not assume the TB-500 component's exact sequence from a blend name.
PEPTALIAS material is for laboratory research only, not human or veterinary use.
Sources: Philp et al., full-length thymosin beta-4 and a seven-residue segment in mouse wounds (2003); Esposito et al., analytical identification of material sold as TB-500 (2012); PEPTALIAS linked supplier reference PDF.