TB-500
Also called TB500, TB 500, Thymosin beta-4, Thymosin beta 4, Tβ4
Educational only, not medical advice. Dosaly reports what has been studied; it isn't a recommendation to use TB-500 or any amount of it. Talk to a clinician.
News · October 30, 2026
Draft HHS policy on compounding
On Oct 30, 2026, HHS said it won't act against licensed pharmacies that compound certain peptides while the FDA reviews them. News reports say the list includes BPC-157, KPV, TB-500, MOTS-c, Epitalon and Semax. It's a draft, not FDA approval.
Not approved as a medicine by the FDA or EMA (as of October 2026).
Research applications
- Heart injury and repair (mouse studies of thymosin beta-4)
- Cell migration and the actin cell skeleton (lab studies)
- Severe dry eye (phase 2 trials of thymosin beta-4 eye drops)
- Venous leg ulcers (phase 2 trial of a thymosin beta-4 gel)
What studies have looked at, not proven uses.
What it is
TB-500 is a lab-made peptide linked to thymosin beta-4, a protein found in most of the body's cells. Most research is on thymosin beta-4 itself, in animals and a few small human trials. Studies on TB-500 itself are scarce.
More detail
TB-500 is a name used for a synthetic peptide linked to thymosin beta-4, a 43-amino-acid protein found in most human cells that binds actin, one of the building blocks of the cell skeleton. Material labelled TB-500 is described in different ways, sometimes as the full protein and sometimes as a short fragment of it, so its exact identity is not standardised. Almost all of the research is on thymosin beta-4 itself: mouse studies of heart injury, cell-migration studies, and small phase 2 human trials of thymosin beta-4 eye drops for severe dry eye and a topical gel for venous leg ulcers. Studies on the TB-500 material itself are scarce.
Evidence listed here
- 2 human studies
- 1 animal study
Results from cells and animals often don't carry over to people. How to read peptide research
Molecular info
- Class
- Synthetic peptide related to thymosin beta-4
- Length
- Not standardized
- Sequence
- Often sold as Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln (a 7-amino-acid fragment of thymosin beta-4)
- Research areas
- Tissue repair, Cardiovascular
Material labelled TB-500 is sometimes the full 43-amino-acid thymosin beta-4 and sometimes a short fragment.
Research
- Human studyCornea · 2015Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial.
Small phase 2 randomized trial of thymosin beta-4 eye drops in severe dry eye.
- Human studyAnn N Y Acad Sci · 2010The effect of thymosin treatment of venous ulcers.
Phase 2 randomized trial of topical thymosin beta-4 in venous leg ulcers.
- Animal studyNature · 2004Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair.
Mouse heart-injury model plus cultured heart muscle cells (thymosin beta-4).
Amounts used in studies
What published studies gave, as each study reports it. Animal amounts are shown as studied and don't translate to people. This is a record of research, not a recommendation: talk to a clinician.
- Animal studymale Sprague-Dawley rats, Achilles tendon transection and repair, 8 per group
Studied at 60 µg/kg/day, once daily (intraperitoneal) for 4 weeks
One of the few published studies that names TB-500 itself; outcomes were tendon histology and strength in rats.
Source: PMID 42542926 - Human studyhealthy volunteers, 4 cohorts of 10
Studied at 42, 140, 420, or 1260 mg, single dose, then once daily for 14 days (intravenous) for 14 days
Placebo-controlled safety study of synthetic thymosin beta-4, the full 43-amino-acid peptide, not the TB-500 fragment.
Source: PMID 20536472