Thymosin Alpha-1 vs TB-500 (Thymosin beta-4)
Despite the shared "thymosin" name, the two are unrelated. Thymosin alpha-1 is a 28-amino-acid immune peptide approved in several countries for hepatitis B; TB-500 is a fragment of thymosin beta-4, an actin-sequestering protein studied in tissue repair.
Thymosin Alpha-1
A 28-amino-acid thymic peptide that modulates T-cell and dendritic-cell function, registered as a medicine in a number of countries.
BEST STUDIED FOR
Repair & immune
Read the cited profile →
TB-500 (Thymosin beta-4)
Thymosin beta-4 — the parent molecule of the TB-500 fragment — is a naturally occurring 43-amino-acid actin-sequestering protein.
BEST STUDIED FOR
Cell-migration and tissue-repair models
R639View product →
Side by side · to buy
Price, purity and dispatch
| Compare | Thymosin Alpha-1 | TB-500 (Thymosin beta-4)10mg |
|---|---|---|
| Price | — | R639 |
| Cost per mg | — | R63.9 / mg |
| Purity (Janoshik) | — | On request |
| Stock | — | Restocking |
| Dispatch | — | When restocked |
| Certificate | — | Request CoA |
| Literature | — | 4 papers → |
| Research focus | Repair & immune | Cell-migration and tissue-repair models |
| Read the cited profile | Notify me |
Prices are read live from the catalogue. Cost per mg is the vial price over its stated mg. Purity is shown only where the certificate is published. Every compound is supplied for laboratory research only.
SIDE BY SIDE
| Thymosin Alpha-1 | TB-500 (Thymosin beta-4) | |
|---|---|---|
| The key difference | Immune modulator (T-cell maturation) | Actin-binding repair peptide (thymosin β4 fragment) |
| Class | Repair & immune | Repair & immune |
| Mechanism | Thymosin α1 acts on innate and adaptive immunity — reported to signal through Toll-like receptors on dendritic cells and to promote T-cell maturation — which is why it is studied as an immune "modifier" in infections, vaccines and oncology. | Thymosin beta-4 — the parent molecule of the TB-500 fragment — is a naturally occurring 43-amino-acid actin-sequestering protein. |
| Status | Approved (thymalfasin) in over 30 countries, mainly for hepatitis B/C and as an immune adjuvant; not registered in South Africa. Ongoing trials in oncology. | Investigational synthetic fragment of thymosin beta-4; not an approved medicine. Most data come from thymosin beta-4 itself in animal models. |
| Reported safety signals | Reviews describe a favourable tolerability record in clinical use; injection-site discomfort is the most cited effect. | No controlled human safety data for the fragment; thymosin beta-4 work is largely preclinical. |
| A key study | A comprehensive review of thymosin α1 in immunocompromised states, malignancy and vaccine response. (World J Virol 2020, PMID 33362999) | A review outlining thymosin beta-4 actin-binding chemistry and its reported regenerative activity across cardiac, corneal and dermal repair models. (Expert Opin Biol Ther 2012, PMID 22074294) |
WHEN TO RESEARCH WHICH
Thymosin alpha-1 for immune-response research; TB-500 for cell-migration and repair models. Both are discussed here strictly as research compounds; nothing on this page is medical advice or a dosing guide.
REFERENCES (PUBMED)
- [Thymosin Alpha-1] Thymosin alpha 1: A comprehensive review of the literature — World J Virol 2020. PMID 33362999
- [Thymosin Alpha-1] Historical review of thymosin α 1 in infectious diseases — Expert Opin Biol Ther 2015. PMID 26098768
- [Thymosin Alpha-1] Aging and Thymosin Alpha-1 — Int J Mol Sci 2025. PMID 41373628
- [TB-500 (Thymosin beta-4)] Thymosin beta4: a multi-functional regenerative peptide. Basic properties and clinical applications — Expert Opin Biol Ther 2012. PMID 22074294
- [TB-500 (Thymosin beta-4)] Thymosin beta 4 promotes corneal wound healing and decreases inflammation in vivo following alkali injury — Exp Eye Res 2002. PMID 11950239
- [TB-500 (Thymosin beta-4)] Thymosin beta 4 and the eye: the journey from bench to bedside — Expert Opin Biol Ther 2018. PMID 30063853
FREQUENTLY ASKED
What is the difference between Thymosin Alpha-1 and TB-500 (Thymosin beta-4)?
Despite the shared "thymosin" name, the two are unrelated. Thymosin alpha-1 is a 28-amino-acid immune peptide approved in several countries for hepatitis B; TB-500 is a fragment of thymosin beta-4, an actin-sequestering protein studied in tissue repair.
What is the regulatory status of Thymosin Alpha-1 and TB-500 (Thymosin beta-4)?
Thymosin Alpha-1: Approved (thymalfasin) in over 30 countries, mainly for hepatitis B/C and as an immune adjuvant; not registered in South Africa. Ongoing trials in oncology. TB-500 (Thymosin beta-4): Investigational synthetic fragment of thymosin beta-4; not an approved medicine. Most data come from thymosin beta-4 itself in animal models.
What safety signals have been reported?
Thymosin Alpha-1: Reviews describe a favourable tolerability record in clinical use; injection-site discomfort is the most cited effect. TB-500 (Thymosin beta-4): No controlled human safety data for the fragment; thymosin beta-4 work is largely preclinical.
Which studies is this comparison based on?
For Thymosin Alpha-1: “Thymosin alpha 1: A comprehensive review of the literature” (PMID 33362999); “Historical review of thymosin α 1 in infectious diseases” (PMID 26098768); “Aging and Thymosin Alpha-1” (PMID 41373628). For TB-500 (Thymosin beta-4): “Thymosin beta4: a multi-functional regenerative peptide. Basic properties and clinical applications” (PMID 22074294); “Thymosin beta 4 promotes corneal wound healing and decreases inflammation in vivo following alkali injury” (PMID 11950239); “Thymosin beta 4 and the eye: the journey from bench to bedside” (PMID 30063853).
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