What it is
TB-500 is a peptide made of 7 amino acids. It is made in a lab. It copies one small section of a natural protein called thymosin beta-4. Thymosin beta-4 has 43 amino acids and is found in almost every cell in the body. The section TB-500 copies is the part that attaches to actin. Actin is the protein cells use to move. Other names: Thymosin Beta-4 fragment, Tβ4 fragment, Ac-LKKTETQ.
What researchers study it for
- Cell movement toward injured tissue
- Wound closing in animals
- Heart tissue repair in mice after heart attack
- Blood vessel growth in animals
- Hair growth in rodents
- Swelling and inflammation in animal models
What the studies found
1. Lab tests proved what TB-500 actually is.
A doping-control lab tested TB-500 product and found it is a 7 amino acid piece of thymosin beta-4, not the full 43 amino acid protein. This matters because almost every study below was done on the full protein. TB-500 copies the active section, so researchers expect similar effects, but the fragment itself has far fewer direct studies.
2. Mice that had a heart attack had less heart damage after treatment.
A 2004 study in the journal Nature gave thymosin beta-4 to mice after a heart attack. The damaged area of the heart was smaller. The heart pumped better. Fewer heart cells died. It worked by turning on a protein called integrin-linked kinase, which keeps cells alive under stress. This was in mice that already had the heart attack, not before it.
3. Skin cells moved 42 percent faster toward a wound.
In a 1999 study, thymosin beta-4 made skin cells travel faster across a scratch in a lab dish. In animals, wounds closed faster and scarred less. Cells have to move to a wound before they can repair it, so faster movement means faster repair.
4. Old rodents grew new blood vessels and hair after treatment.
Old animals grow fewer new blood vessels, so their wounds close slowly. Thymosin beta-4 raised blood vessel growth in both young and old rodents. It also increased hair growth in both groups.
5. Some products sold as TB-500 did not match the label.
A 2023 lab study tested TB-500 and TB-1000 sold online. Some vials did not contain what the label said. This is why a lab test report, called a certificate of analysis, matters more than the product name.
6. No study has measured how long TB-500 stays in the blood.
All timing data is from the full thymosin beta-4 protein. In human volunteers given the full protein, it cleared the blood quickly and did not build up after 10 daily doses. Numbers you see online for the TB-500 fragment are guesses based on the full protein.
How much research exists
The full thymosin beta-4 protein has many animal and cell studies and a few early human trials. The TB-500 fragment has very few studies of its own. No completed human trial of TB-500 has been published.
Facts
- Formula: C38H68N10O14
- Weight: 889.0 g/mol
- CAS number: 885340-08-9
- Sequence: Ac-LKKTETQ
- Storage: freeze the dry powder away from light. Keep mixed solution in the fridge.
Legal status
Not approved by the FDA or any other agency for human use. Banned in sports by WADA under section S2.
For research use only. Not for human use. Nothing here is medical advice.