Peptides
TB-500 Fragment
Also called TB-500 (FRAG) · LKKTETQ
TB-500 Fragment is sought for tendon, joint and muscle recovery, often alongside BPC-157. The useful question is whether a claim actually concerns this fragment: full thymosin beta-4 research and vaguely labelled “TB-500” experiences cannot establish the same result.
Dosage & duration
Fragment-specific dose evidence.
Human recovery use of identified fragment
Published example · product-specific- Dose
- No verified effective human range
- How often
- No established daily or weekly schedule
- How long
- No established recovery cycle
Full-TB4 regimens and analytically unconfirmed TB-500 reports cannot fill this gap.
Reported amounts used contradictory mg/mcg units; those numbers cannot support a regimen.
The practical difference
Does the recovery claim match the fragment?
People seek the fragment for tendon, joint and muscle recovery. A similarly named product may contain a different peptide.
| What to check | TB-500 Fragment | Full thymosin beta-4 |
|---|---|---|
| Identity | A short fragment | The full-length peptide |
| Product label | May be sold as “TB-500” | May also be sold as “TB-500” |
| Recovery evidence | Human benefit remains unestablished | Its studies do not establish fragment benefits |
Why people consider the fragment
People dealing with persistent aches or a slow return to training hope it will improve movement and tissue repair. Those aims are understandable, but reliable recovery benefit from this specific fragment is not established in the checked human evidence.
TB-500 labels can refer to different things
This entry concerns the short fragment associated with the LKKTETQ sequence, often acetylated. Full-length thymosin beta-4 is a different product. A blend that simply says “TB-500” does not settle which one is present.
Why daily-versus-weekly answers conflict
Descriptions of these products may mix the two molecules, speculative half-lives and inconsistent units. A detection study can identify a compound without showing how to treat an injury. Rather than invent a clean range from mixed reports, the dose section keeps that gap visible.
A better way to read a recovery claim
Check the exact molecule, route, injury and outcome. Less pain does not itself prove a tendon has healed, and a combination report cannot show what the fragment contributed.
Model details: TB-500 Fragment · relative timing
Compare timing and buildup for this compound. The values are not blood concentrations or a measure of strength.
Shows a relative timing scenario; absolute blood concentrations are not calibrated.
Timing assumptions and sources
The 2024 study examines human-serum/enzyme incubations and rat urine. Metabolite detection to 72 h is not the parent plasma half-life; legacy 0.96 h remains an assumption.
One 1 mg input peaks at 1 relative unit after a single dose. Other amounts scale proportionally; overlapping doses add when accumulation is on. Different compounds use separate relative scales.
- Timing half-life used
- 0.96 hours
- Absorption half-life assumed
- 0.24 hours
- Reference amount for the relative scale
- 1 mg
- Absorption half-life is assumed to be one quarter of the slower timescale (0.24 h); it is not a measured absorption parameter.
- A single 1-unit input has a peak of 1 relative unit; scaling and repeated-dose addition are mathematical assumptions. This normalization is independent of the example dose.
- No human parent-peptide systemic calibration established in reviewed sources.
- Ac-LKKTE wound-assay activity is a metabolite effect, not a blood exposure endpoint.
- Simultaneous quantification of TB-500 and its metabolites in in-vitro experiments and rats by UHPLC-Q-Exactive orbitrap MS/MS and their screening by wound healing activities in-vitro.
The 2024 study examines human-serum/enzyme incubations and rat urine. Metabolite detection to 72 h is not the parent plasma half-life; legacy 0.96 h remains an assumption.
tb-500-frag-relative-timing-2026-10 · version 1
Common questions
Is this the same as full thymosin beta-4?
No. This page concerns the short fragment; full-length TB4 is a different molecule.
Why not copy a TB-500 dose from another page?
The product may be different, and an unverified “TB-500” report cannot establish a fragment-specific effective schedule.
Sources Labels, studies and notes behind this guide
Catalog evidence: Animal or laboratory research. This describes the type of evidence, not a clinical review of every claim.
Summary and fact source checks: 2026-10-07. This records source checking, not medical review of the whole page.
Notes on the quick facts
- Main goal
- Recovery is the hoped-for benefit, not a proven fragment effect.
- Critical comparison
- Evidence is not interchangeable.
- Dose question
- Mixed naming and units undermine many reported schedules.
- 1. FDA TB-500 scientific review
Fragment-specific assessment; distinguish Ac-LKKTETQ from full thymosin beta-4 and analytical detection from therapeutic evidence.
- 2. Original TB-500 chemical-identification report
Mass-spectrometry identification of acetylated fragment in a seized product; not a human recovery trial.
- 3. Simultaneous quantification of TB-500 and its metabolites in in-vitro experiments and rats by UHPLC-Q-Exactive orbitrap MS/MS and their screening by wound healing activities in-vitro.
The 2024 study examines human-serum/enzyme incubations and rat urine. Metabolite detection to 72 h is not the parent plasma half-life; legacy 0.96 h remains an assumption.
- 4. TB-500 Ac-LKKTETQ metabolism study, 2024
Original standalone fragment/metabolite study in vitro and rats; Ac-LKKTE metabolite showed wound-assay activity, not proof of human repair.
- 5. TB-500 fragment identification in horse plasma
Original analytical study defines administered TB-500 as N-acetylated LKKTETQ in two horses; not human PK or efficacy.
- 6. Full-length thymosin beta-4 IV trial
Comparator identity only: a different 43-residue molecule studied in human IV trials.
Related compounds and examples
Related compounds
BPC-157
Why people consider BPC-157 for tendon, ligament, muscle and gut recovery, plus oral versus injected forms, expected timing and practical trade-offs.
TB-500 (Thymosin Beta-4)
Why people research TB-500 for tendon, muscle and joint recovery, how reported courses are described, and what to know when comparing it with BPC-157.
ARA-290 (Cibinetide)
ARA-290 for nerve symptoms: research doses, 28-day studies and realistic expectations for neuropathy.