TB-500 in Perth: the Thymosin Beta-4 Fragment

What is TB-500?

TB-500 is the Ac-LKKTETQ fragment described in the Form Laboratories catalogue, with seven amino acids corresponding to positions 17–23 in the parent protein, thymosin beta-4. The catalogue gives the parent a length of 43 amino acids. The counts describe the full chain and its much shorter region. Esposito and colleagues identified the fragment in their 2012 analytical study in Drug Testing and Analysis. Those details describe a particular short sequence, rather than every substance carrying a similar name. The starting point is the piece itself: its letters, its length and its position.

The TB-500 research guide follows the literature behind that catalogue description. The distinction is simple enough to lose in a headline: a paper can mention thymosin beta-4 without having tested Ac-LKKTETQ. Reading the molecule named in the methods keeps that paper attached to its actual subject. The parent and the fragment belong in the same discussion, but they need their own labels.

Evidence limits

What are the limits of the TB-500 evidence here?

The evidence boundary matters before the interesting result. Chemical identification answers what was detected in an analysed sample; it does not answer what happens in a person. A mouse experiment reports an animal observation. Neither kind of paper, by itself, settles whether a named catalogue material matches the sample in that publication. The CAS entry and the study setting are useful limits because each points to a specific question still needing its own evidence.

Why is TB-500 different from thymosin beta-4?

TB-500 names a fragment in this catalogue, while thymosin beta-4 names the parent from which its sequence comes. The catalogue places Ac-LKKTETQ within the larger chain; the fragment does not contain all of that chain. Van Troys and colleagues examined actin interaction in full-length protein variants in the EMBO Journal in 1996. The researchers investigated which regions participated in that interaction. Their laboratory work concerns the parent's structure, so its findings need that label when carried into a discussion of the fragment.

The Van Troys abstract describes a central motif at residues 17–22 and a separate starting region at residues 1–16 in the full-length laboratory variants. Esposito's 2012 characterisation concerns the 17–23 fragment instead. The endpoints are worth preserving: the binding-study motif and the isolated fragment are related descriptions, not identical study objects. The table below holds the two identities side by side, so that a shared stretch does not swallow the rest of the protein.

How was the TB-500 fragment identified?

Esposito and colleagues identified Ac-LKKTETQ in TB-500 using laboratory analysis in their 2012 Drug Testing and Analysis paper. The abstract describes chemical detection and identification of the short peptide in the studied material, using laboratory methods. The team also synthesised the reported fragment. The important boundary is the sample in that paper. The result gives a published chemical description for the fragment; it does not establish the contents of a different sample bearing the TB-500 name. The sequence is therefore more useful here than treating the name as proof.

The TB-500 catalogue directs the CAS enquiry to report checking (Form Laboratories record, read 2 October 2026). The quality article on how a lot record connects to paperwork explains the role of record matching. That paperwork question remains separate from Esposito's scientific characterisation. A publication's sample and an order's record cannot be made interchangeable by placing the same short name on both. This page draws no identity conclusion about a supplied batch.

What did the mouse fragment study report?

Philp and colleagues reported that a synthetic LKKTETQ peptide promoted wound repair in aged mice, with activity comparable to the parent in that mouse model, in Wound Repair and Regeneration in 2003. The abstract also describes experiments with full-length thymosin beta-4 in diabetic and aged mice. The fragment finding must stay attached to the aged animals, rather than becoming a claim about every experiment in the paper. The reported short sequence is LKKTETQ; Esposito's analytical paper names Ac-LKKTETQ. Preserving each paper's own wording avoids quietly treating the two descriptions as one tested material.

The mouse result explains why the short region attracts research attention. It does not erase the identity distinction. Comparable repair activity in the aged-mouse experiment is a finding within that setting, not a declaration that fragment and parent behave the same everywhere. The study can be interesting without answering a human question. Its value on this page is precise: a named synthetic peptide, a named animal model and a result kept within the experiment that produced it.

What has the TGA said about TB-500?

The TGA named TB-500 among its unapproved peptide examples on 13 April 2026. On 19 June 2026, the Chief Medical Officer and TGA stated that these peptide goods “have not been evaluated by the TGA for safety, quality or effectiveness.” The notices concern peptide products and public health, rather than the part-and-whole question in the scientific papers. Keeping the dates with the statements identifies the official record being summarised. The advisory and the joint statement sit beside the legislation below, with each source answering its own question about the material.

Instrument F2026L01327, the October 2026 Poisons Standard checked on 1 October 2026 UTC, lists TB-500 under Schedule 4, with Appendix D clause 5 item 38, and thymosin beta 4 under Schedule 4, with clause 5 item 39. The separate entries retain the two names in the legislative record. The article on how scheduling reaches Western Australia explains the wider state-law context. The classification above is tied to the October instrument and its recorded check date.

How does the sport listing name TB-500?

Sport Integrity Australia lists Thymosin Beta-4 (TB-500) as prohibited in sport, according to the peptide-page record retrieved on 9 September 2026. The listing puts TB-500 in parentheses after the parent protein's name. That naming is useful to notice after separating the fragment from the full protein. The sport entry is a record about sport; its label does not change the molecular description in Esposito's analytical study or the catalogue. Reading the official name alongside the scientific one keeps the two records legible without treating a shared heading as chemical evidence.

How is TB-500 stored and dispatched from Perth?

The Form Laboratories catalogue records TB-500 as a freeze-dried research reference with storage recorded at 2–8 C, kept dry and away from light. The shipping page describes Perth dispatch after the bank transfer has reached the supplier and been matched to the order. That page also says the lab report stays in the account instead of travelling inside the parcel. For a compound whose catalogue CAS field asks for report checking, the location of the paperwork matters. Storage, dispatch and the order record are separate details; none establishes the chemical identity of the delivered material.

The catalogue listing for the TB-500 reference material supplied belongs in this record-and-logistics context. The shipping record for our Perth peptides store says parcels travel domestically with Australia Post or CouriersPlease, in plain outer packaging, and a tracking email follows handover. A saved report remains attached to the order even while the parcel travels. Those are document and dispatch facts. The catalogue name, the published fragment sequence and a particular report still need to be read as distinct records.