Research comparison
TB-4 vs TB-500 (Thymosin Beta-4)
TB-4 and TB-500 are two names for the same molecule, and the naming causes a lot of confusion. TB-4 is the literature name for thymosin beta-4, the endogenous 43-amino-acid actin-binding peptide; TB-500 is the research-market name for the synthetic version of it. The CertaPeptides material is supplied and independently tested as the full-length thymosin beta-4 sequence — its batch COA and molecular weight (about 4,963 g/mol) confirm the complete peptide, not a shortened fragment.
Side by side
| Thymosin Beta-4 (TB-4) | TB-500 | |
|---|---|---|
| What it is | Thymosin beta-4 (literature name) | Thymosin beta-4 (research-market name) |
| Sequence | Full 43-amino-acid actin-binding peptide | Full 43-amino-acid sequence (per our batch COA) |
| Molecular weight | ~4,963 g/mol | ~4,963 g/mol (matches full length) |
| Origin | Naturally occurring in many tissues | Synthesised; supplied as the acetate salt |
| Research focus | Actin regulation, cell migration, tissue repair models | Studied in the same tissue-repair context |
How they differ in research
Thymosin beta-4 is a 43-amino-acid peptide present in many tissues that sequesters actin and is studied in cell-migration and tissue-repair models. 'TB-4' is simply the name used for it in the research literature.
'TB-500' is the name the research-compound market uses for the same molecule. It is worth being precise here because some sources loosely describe TB-500 as only the short actin-binding fragment — but the CertaPeptides material is the full-length sequence, confirmed by its independent COA and its ~4,963 g/mol mass. As a reseller we supply it as provided by our supplier, as the acetate salt.
So the practical answer is that TB-4 and TB-500 refer to the same thymosin beta-4 peptide; the difference is naming, not chemistry. The batch certificate of analysis is the reliable statement of exactly what is in a given vial.
Which suits which research question
Because TB-4 and TB-500 denote the same peptide, the choice is really about sourcing: the certificate of analysis for the specific batch is what documents identity and purity. CertaPeptides publishes a resolvable third-party COA for the TB-500 we supply, confirming the full-length sequence. For laboratory research use only.
Frequently asked questions
Is TB-500 the same as Thymosin Beta-4?
Yes — they are two names for the same molecule. TB-4 is the literature name for thymosin beta-4; TB-500 is the research-market name for the synthetic version. The CertaPeptides material is the full-length 43-amino-acid sequence, confirmed by its batch COA and its molecular weight of about 4,963 g/mol.
Is TB-500 just a small fragment of thymosin beta-4?
Some sources describe TB-500 that way, but it is not true of the material we supply. Our batch COA and the measured molecular weight (about 4,963 g/mol) confirm the complete 43-amino-acid thymosin beta-4 sequence, not a shortened fragment. Always check the batch COA for what a specific vial contains.
Why does the naming matter?
Because 'TB-4' and 'TB-500' are used loosely across the market, the only reliable statement of what is in a vial is its batch certificate of analysis — not the label alone.
This comparison describes objective compound pharmacology reported in the research literature. It is not medical guidance and makes no human efficacy, dosing, or therapeutic claims. All products are supplied by CertaPeptides (CERTALAB S.R.L.), a reseller, for laboratory research use only — not for human or animal consumption.