TB-500 is a synthetic peptide (Ac-LKKTETQ) that reproduces the short actin-binding domain of thymosin beta-4, a naturally occurring protein. Its studied activities — actin binding, cell migration, angiogenesis and wound repair — come from animal and laboratory work. It is not approved by any regulator, for any use, and is prohibited in sport.
By Tessaro Pty Ltd, the maker of Pepti · Last reviewed
This page is a reference, not a protocol. It sets out what the published research actually reports, clearly separating animal and laboratory findings from human ones, explains why no reliable human half-life exists for this compound, and describes what a clean record holds. It contains no dose figures and no schedule, and the section further down explains why that is deliberate rather than an omission.
| Property | Value |
|---|---|
| Type | Synthetic peptide (Ac-LKKTETQ) reproducing the seven-amino-acid actin-binding domain of thymosin beta-4 |
| Evidence base | Preclinical — animal and in-vitro (cell) studies. Direct human data lacking |
| Half-life | No reliable human half-life has been published |
| Development status | Investigational research peptide; prohibited in sport |
| Regulatory status | Not approved by any regulator for any indication |
TB-500 (Ac-LKKTETQ) is a synthetic peptide derived from the active site of thymosin beta-4, reproducing its short actin-binding domain (Rahaman et al., 2024). The activities associated with that region of the parent protein — actin binding, cell migration, angiogenesis and wound repair — are the reasons it draws interest, but every one of them is described from animal and in-vitro work, not from trials in people.
The clearest controlled evidence for the actin-binding fragment is preclinical and, notably, concerns the parent protein and its synthetic domain rather than “TB-500” as sold. Thymosin beta-4 accelerated dermal wound repair in db/db diabetic mice and in aged mice, with increases in keratinocyte migration and collagen deposition; and the actin-binding domain, reproduced as the seven-amino-acid synthetic peptide LKKTETQ, promoted repair in the aged animals comparably to the full molecule (Philp et al., 2003). These are animal results, not evidence of a human outcome.
For TB-500 itself the record is thinner than the marketing suggests. A 2024 analytical study states plainly that the biological effects of TB-500 have not been well documented, and it characterised the peptide and its metabolites only in laboratory systems and in rats (Rahaman et al., 2024). A 2026 sports-medicine review reaches the same place from the clinical side: human data are lacking, there is a lack of evidence to support clinical use, and TB-500 remains a banned substance in sport (Mayfield et al., 2026). Reviews of injectable peptides group it among unapproved compounds that lack an established human safety profile (Moiz et al., 2026).
A half-life is the time it takes for half of what is present to clear, and it is the single number a decay curve is built from. For TB-500 it does not exist: no reliable human half-life has been published. The evidence is preclinical, and the metabolism work that has been done was carried out in laboratory systems and in rats — informative about the molecule, silent about how long it persists in a person.
The practical consequence is simple: you cannot chart a decay curve for TB-500, because there is no trustworthy human value to put into one. Any figure circulating online as its “human half-life” is not drawn from a human study, because none has been published. A record that invents a half-life inherits that invention. What you can record reliably does not depend on a half-life at all: the dated history of when you logged, what figure you used, and when anything changed.
A lyophilized, or freeze-dried, powder is the stable, shelf-storable form of a peptide; reconstituting it with a diluent trades that stability for a solution that needs more care. Standard product labeling for lyophilized peptide injectables bears this out. The US FDA label for glucagon, a lyophilized peptide, stores the powder at controlled room temperature and protected from light, and directs that once reconstituted the solution be used without delay with any unused portion discarded (US FDA label, glucagon for injection).
Different products set different limits after reconstitution, and material supplied without a preservative is less forgiving again. The governing instruction is whatever the source of your own material specifies — this page supplies no figure for it. For record-keeping, note the form you received, the diluent and volume if you mixed it yourself, and the date you reconstituted, so the age of the vial is never a guess.
Tracking TB-500 in Pepti is the same disciplined logging it applies to anything else. The fields that matter are the date and time, the figure you already have in the unit you think in, the injection site, and — if you reconstituted it yourself — the diluent volume and the resulting concentration.
The reconstitution calculator converts the figure you already have into a draw volume, expressed only as variables: the concentration is the peptide amount in the vial divided by the volume of water you add; the volume to draw is your figure divided by that concentration; and the syringe units are that volume multiplied by one hundred on a U-100 syringe. Those are the relationships, not a recommendation — you supply the figure, Pepti does the arithmetic. The injection site rotation guide sets out the fixed 12-site sequence Pepti steps through, so each injection lands away from the last. And because no reliable human half-life exists for TB-500, the half-life decay calculator has nothing trustworthy to chart here: it only ever plots a value you type in, and for this compound there is no sound human value to enter.
TB-500 is an unapproved research peptide. There is no approved label for it anywhere in the world, which means there is no authorised dose, no approved titration path, and no clinician-facing guidance outside research settings. Any figure published as a “typical dose” for it is not drawn from an approved source, because no such source exists. It comes from forum consensus, from vendor copy, or from someone’s reading of an animal study — none of which carries the authority its typographic confidence implies.
Pepti does not supply the figure, and it will not, for this compound or any other. Pages that publish dose tables for unapproved compounds are publishing folklore with the typography of evidence — the numbers look authoritative because they sit in a table, not because anything stands behind them. The figure belongs to you and whoever directs your use. The arithmetic is what we are for.
A record worth keeping is one you can still read honestly months later. For TB-500 it holds the following.
The reconstitution calculator turns the figure you already have into a draw volume and a count of doses per vial, and a peptide tracker app keeps every one of those entries on a single timeline rather than scattered across notes and memory.
TB-500 is a synthetic peptide, Ac-LKKTETQ, that reproduces the short actin-binding domain of thymosin beta-4, a naturally occurring protein. Its studied activities - actin binding, cell migration, angiogenesis and wound repair - come from laboratory and animal work, not from trials in people. It is not an approved medicine.
Not exactly. Thymosin beta-4 is the full naturally occurring protein, while TB-500 is a short synthetic fragment corresponding to its actin-binding region. Findings for the parent protein do not automatically transfer to the fragment, and a 2024 analysis notes that the biological effects of TB-500 itself have not been well documented.
TB-500 is not approved by any regulator for any indication, and published reviews classify it as an unapproved peptide that lacks an established human safety profile. It is also a prohibited substance in sport. This page is a record-keeping reference, not an endorsement of use.
No reliable human half-life has been published. The evidence is preclinical - laboratory systems and animals - and no human pharmacokinetic study establishes how quickly TB-500 clears. A number presented as its human half-life is not coming from a human study, because none exists, so this page gives none.
No. Pepti supplies no dose figures for TB-500 or anything else. It records the figure you already have from whoever directs your use, converts it into a draw volume and syringe units, tracks what is left in each vial, and keeps the injection-site sequence. The arithmetic is ours - the figure is not.
This page is a reference on published evidence and record-keeping. It does not recommend TB-500 or any other substance, and it provides no dose figure, no titration amount, and no schedule. TB-500 is an unapproved research peptide and is not approved for any use.
The Pepti peptide tracker for iPhone keeps the log, the injection-site sequence, the vial count and your observations in one place.
Not medical advice. Pepti is a record-keeping and measurement tool, not a medical device.
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