TB-500 vs Thymosin Alpha-1
Key differences, research and prices — side by side.
Despite the similar names, they are unrelated. TB-500 comes from thymosin beta-4, which binds actin and affects cell movement. Thymosin alpha-1 is a 28-amino-acid thymic peptide that modulates immune cells and is approved as a drug (Zadaxin) in several countries outside the U.S.
| TB-500 | Thymosin Alpha-1 | |
|---|---|---|
| What it is | TB-500 is a synthetic fragment of thymosin beta-4, a 43-amino-acid protein found in almost every human cell. | Thymosin alpha-1 is a 28-amino-acid peptide originally isolated from the thymus, the organ where immune T-cells mature. |
| How it works | Thymosin beta-4 binds actin, the protein that forms a cell’s internal scaffold, which influences how cells move and migrate into damaged tissue. | It acts on immune cells through toll-like receptors and has been shown to influence T-cell maturation and the body’s response to infection. |
| Research areas |
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| Evidence | Mostly animal & lab studies | Human clinical studies |
| Regulatory status | Not approved by the FDA. Most published research uses full-length thymosin beta-4 rather than the TB-500 fragment. Prohibited in sport by WADA. | Approved as a drug (thymalfasin, Zadaxin) in several countries outside the U.S. Not approved by the FDA. |
| Research area | Tissue Repair | Immune |
| Sequence | Ac-LKKTETQ | — |
| Lowest price | $5.10/mg → | $5.22/mg → |
| Tested vendors | 2 | 2 |
| Third-party lab results | 5 COAs | 3 COAs |
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Educational comparison of published research — not medical advice, and not a recommendation of either compound. Prices are for reference only. Compounds referenced are sold by third parties for laboratory research use only and are not for human consumption.