THE TB-500 FIELD GUIDE
Follow the evidence.
An honest study map: what was tested, who or what was studied, and where the result stops.
Plain-language guide · Checked 2026-10-22 · Source links below
← Back to the field guideA better way to read a study
Begin with the question, not the headline. Was the study trying to identify a molecule, explain a process, test early safety, or measure a health benefit? These questions need different methods. An excellent chemical identification study can still tell us little about how a person would feel.
Next check the comparison. A control gives researchers a way to judge what would happen without the tested substance. Random assignment helps keep the groups fair. Masking means people do not know which treatment was given, which can reduce the effect of expectations.
Finally, look for the main outcome chosen before the results were known. A study may measure many things. Finding one positive side result after missing the main goal is weaker than meeting the planned main goal. The size of the study and the length of follow-up also matter.
What can the human research tell us?
Some human studies concern full-length thymosin beta-4 formulations. Early safety studies in healthy volunteers looked at tolerance, body handling and related measures. They were not trials of injury recovery with retail TB-500 fragments. A small early study also cannot rule out rare or long-term harms.
Sources: Ruff and colleagues, 2010 — intravenous thymosin beta-4 in healthy volunteers · Wang and colleagues, 2021 — recombinant thymosin beta-4, phase I
Why the route matters
An eye drop, a skin product and an injection do not reach tissue in the same way. Each has a different formulation and exposure pattern. The route is part of the treatment being tested. Changing it changes the research question.
When people discuss the eye studies, keep the studied eye formulation and condition in the sentence. Dropping those details can turn a narrow finding into a much broader claim. The same rule applies to a study of a wound in a rat or a scratch across a layer of cells.
Unknown is a useful answer
Unknown does not mean a substance has no effect. It means the evidence does not yet settle the question. A useful next study would name the exact substance, use sound controls, measure outcomes that matter to people and report harms as carefully as benefits.
A study registry entry tells you a trial has been registered. It does not tell you the trial finished, produced usable data or found a benefit. A paper title, press release or before-and-after story is also only the start of a check. Follow the full record and ask what the researchers actually measured.
OPEN THE ORIGINAL PAPERS
The study explorer.
Search by year, molecule or question. These are selected studies, not a complete review.
9 studies shown
Acetylated fragment
What was inside a TB-500 sample?
Researchers identified the acetylated seven-amino-acid fragment Ac-LKKTETQ in a material sold as TB-500 and made a reference sample for chemical testing.
An identity and detection study. It did not test health benefits in people, and it does not identify every product sold under the same name.
Fragment and metabolites
What happens when the fragment breaks down?
The team measured TB-500 and metabolites in laboratory systems and rats, and tested wound-closure activity in cells.
These are preclinical findings. Cell movement in a dish and metabolism in rats do not establish human injury recovery or a safe personal-use plan.
Full-length thymosin beta-4
Which part interacts with actin?
Mutational analysis helped map the actin-binding region of thymosin beta-4.
A study of molecular interactions, not a trial showing that a retail fragment improves a person’s recovery.
Thymosin beta-4 and related fragments
A region linked to blood-vessel growth
Researchers examined the actin-binding region in cell and vessel-growth models.
Biological activity in a model is not proof of a net health benefit in people. Full sequence and experimental conditions still matter.
Full-length thymosin beta-4
Skin-wound repair in rats
The study tested full-length thymosin beta-4 in a rat full-thickness skin-wound model and reported faster repair.
A rat skin model cannot settle whether an injected TB-500 fragment heals a human tendon, muscle or joint.
Full-length thymosin beta-4
Early intravenous safety research
A randomized placebo-controlled study examined single and repeated intravenous administration in healthy volunteers.
The purpose was early safety and body handling, not proving a treatment for an injury or checking every risk over years.
Recombinant thymosin beta-4
A phase I study of NL005
A first-in-human study assessed a defined recombinant formulation, including tolerance, body handling and anti-drug antibodies.
Evidence about this formulation and study population does not establish safety or benefit for an online product with a different identity.
Full-length thymosin beta-4 eye formulation
A small study in severe dry eye
A 9-person randomized vehicle-controlled trial of RGN-259 reported improvements in eye discomfort and surface staining.
Very small study in a specific eye condition. It did not test a TB-500 fragment injection or sports recovery.
Full-length thymosin beta-4 eye formulation
A small trial in corneal healing
In 18 participants, complete healing at 4 weeks occurred in 6 of 10 treated participants and 1 of 8 controls. The main comparison had p = 0.0656.
The primary result did not meet the conventional 0.05 significance threshold. A later secondary result does not erase that limitation. This was a specific eye formulation and condition.
The original sources.
Selected research papers and official guidance. Checked October 22, 2026.
- Esposito and colleagues, 2012 — chemical identification of a TB-500 sampleOriginal laboratory study
- Rahaman and colleagues, 2024 — TB-500 and its breakdown productsOriginal laboratory and rat study
- Van Troys and colleagues, 1996 — mapping the actin-binding siteOriginal laboratory study
- Philp and colleagues, 2003 — the actin-binding region and blood-vessel growthOriginal preclinical study
- Malinda and colleagues, 1999 — full-length thymosin beta-4 in rat skin woundsOriginal animal study
- Ruff and colleagues, 2010 — intravenous thymosin beta-4 in healthy volunteersOriginal early human safety study
- Wang and colleagues, 2021 — recombinant thymosin beta-4, phase IOriginal early human safety study
- Sosne and colleagues, 2015 — RGN-259 in severe dry eyeOriginal small human trial
- Sosne and colleagues, 2023 — RGN-259 in neurotrophic keratopathyOriginal small human trial
- Health Canada, April 9, 2026 — online injectable peptide advisoryCanadian regulator
- Health Canada — how to search the Drug Product DatabaseCanadian regulator
- Health Canada — Drug Product Database searchOfficial authorization lookup
- WADA — 2026 Prohibited List, section S2.3Official sport rules