TB-500
Also known as: Thymosin Beta-4 fragment, TB4 frag
By GLPeptideSciences Editorial Team · How we evaluate evidence · Reviewed by Dr. George S. Watson, MD, Cardiothoracic Surgeon · Updated 2026-06-02
A synthetic peptide based on an active region of thymosin beta-4, a naturally occurring protein involved in cell migration and tissue repair.
What it is & how it works
What it is
TB-500 is a synthetic peptide based on an active region of thymosin beta-4 (TB4), a protein found naturally in many tissues that plays a role in actin regulation and cell migration — processes central to wound healing.
How it is thought to work
By influencing actin (a structural protein inside cells), TB4 and its fragments are studied for their role in helping cells move to and rebuild damaged tissue, and for promoting new blood-vessel formation. The recovery effects discussed in the community extrapolate from this preclinical biology.
The evidence gap
The parent protein has a respectable research base; the specific TB-500 fragment sold on the research market has far less direct human data. Treat efficacy claims as preclinical-to-anecdotal, not clinically proven.
What it's discussed & studied for
- Soft-tissue and muscle recovery
- Flexibility and range of motion
- Wound and tissue repair
Discussion of a use is not a claim that it works or is approved.
Research status
Preclinical research on thymosin beta-4 and its fragments; limited human data specific to the TB-500 construct.
Evidence quality
Mostly animal and cell-based. The parent molecule (thymosin beta-4) has more literature than the TB-500 fragment specifically. Human reports are anecdotal.
Dosing discussion
Community protocols often reference a loading-then-maintenance pattern of subcutaneous milligram dosing per week. None of this is clinically validated; it reflects community convention, not evidence.
Educational summary of what is discussed in the literature and community — not a dosing recommendation or medical advice.
Safety & harm reduction
Human safety data is limited. As with other research peptides, sourcing quality (purity, sterility) is the most actionable risk. Not FDA-approved for human use.
Sourcing literacy
Look for identity/purity testing and endotoxin results. TB-500 and thymosin beta-4 are sometimes conflated by sellers — they are related but not identical.
Selected literature
- PubMed: thymosin beta-4 in tissue repair — Literature on the parent protein; TB-500 fragment data is thinner.
FAQ
Is TB-500 the same as thymosin beta-4?
Not exactly. TB-500 is based on an active fragment of thymosin beta-4. They are related but distinct, and sellers sometimes blur the line.
Is there human trial evidence for TB-500?
Specific human trial evidence for the TB-500 construct is limited. Most support is preclinical.