TB-500 research starts with a naming problem: the label points to a 43-residue protein, while the literature often means a seven-residue fragment. This guide separates the two.
Last updated 27 October 2026 · Written by the SHLabz research team
Ask three sources what TB-500 is and you may get three answers. A sports regulator calls it another name for thymosin beta-4. The FDA describes it as a fragment of that protein. Meanwhile, a doping-control paper identifies it as a veterinary preparation built around one short, acetylated sequence.
None of those sources is careless. Instead, the name has drifted between a protein, a fragment and a product. What follows sets out the molecules first, then the regulatory position, and then why the confusion persists.
Quick answer: TB-500 research covers two different molecules. Thymosin beta-4 is a 43-residue protein that binds actin. TB-500, in the strict sense, is a seven-residue fragment of it, LKKTETQ, with an acetylated end. Neither holds a marketing authorisation, and WADA bans thymosin beta-4 at all times. So read the identity data on a certificate, not just the name.
A Protein and a Fragment
Thymosin beta-4, often written Tβ4, is an endogenous peptide of 43 amino acids. Biochemists know it mainly for its relationship with actin, the protein that forms much of the cell’s internal scaffold.
TB-500, by contrast, began as a trade name. A 2012 study in the Journal of Chromatography A describes it as a veterinary preparation whose key ingredient is the peptide LKKTETQ, with an acetylated N-terminus. That seven-residue stretch corresponds to positions 17 to 23 of thymosin beta-4. In other words, the fragment covers about a sixth of the parent sequence.
Regulatory Status of TB-500
Neither the protein nor the fragment holds a marketing authorisation. Sport Integrity Australia states that thymosin beta-4 is not approved for human use anywhere in the world. Similarly, the US Food and Drug Administration notes that it has not identified any human exposure data for the fragment.
That FDA note comes from its list of bulk substances that may present significant risks in compounding. The page names “Thymosin beta-4, fragment (LKKTETQ), also known as TB-500” in a table of substances once in category 2 and later withdrawn by their nominators. Its entry flags a possible risk of immunogenicity, partly through aggregation and peptide-related impurities.
Sport adds a further rule. Citing the 2026 WADA Prohibited List, Sport Integrity Australia places thymosin beta-4 under S2.3, growth factors and growth factor modulators, banned at all times. It adds that a therapeutic use exemption would not be granted for it in any medical condition. Accordingly, SHLabz supplies TB-500 strictly as a laboratory research material, not approved for human use in the UAE.
TB-500 Research and the 2026 GCC Actions
Gulf regulators moved on peptide products three times in 2026. First, in July, the Emirates Drug Establishment acted against 71 sources selling unapproved peptide products. It also referred 14 influencers over online promotion of medicines. The Dubai Health Authority issued a circular (CIR-2026-00000107, 29 July 2026) on handling peptide products in healthcare facilities.
Next, on 27 August, The Peninsula reported a circular from Qatar’s Ministry of Public Health. It bans the import, trading, use and promotion of unlicensed peptide preparations. It also covers products labelled “for research purposes” when they are used or promoted for human use.
Then, on 30 September, the Saudi Food and Drug Authority took action against websites selling unregistered peptides. It said some sellers had falsely presented their products as tested and officially approved. In short, a research label describes intended use. It does not turn a product into an approved medicine, and it gives no cover for human-use marketing.
Jordan’s Food and Drug Administration (JFDA) warned on 3 September 2026 that it had closed more than 10 online pages and six gyms selling unregistered peptide products (Jordan News, 3 Sep 2026).
Thymosin Beta-4 and Actin
Actin exists in two states inside a cell. As single units it floats free, and as filaments it builds structure. Thymosin beta-4 binds the single units and holds them in reserve, which is why a 2005 review in Trends in Molecular Medicine called it the major actin-sequestering molecule in eukaryotic cells.
The fragment matters because of where it sits. According to the 2012 doping-control paper, the 17–23 segment is the active site within thymosin beta-4 responsible for actin binding. That gives a chemical reason for choosing that particular stretch. However, it does not make a seven-residue fragment equivalent to the whole 43-residue protein.
Why the Names Get Conflated
Several habits blur the line. First, sellers and forums often use TB-500 as shorthand for thymosin beta-4 in general. Second, regulators sometimes follow that usage, so Sport Integrity Australia lists TB-500 among the other names for the full protein. Third, the FDA uses the opposite convention and ties TB-500 to the LKKTETQ fragment.
Labels and certificates inherit the same ambiguity. Our own certificate, for example, prints the compound name as “TB500 (Thymosin B4 Acetate)”, pairing the trade name with the parent protein and its acetate salt form. That is a common naming convention in this market rather than a sequence. For that reason, the useful habit is to read the identity data on a certificate, not just the name at the top.
What TB-500 Research Examines
Most TB-500 research in the strict sense is analytical. The 2012 study, for instance, developed liquid chromatography–mass spectrometry methods to detect acetylated LKKTETQ and its metabolites in equine urine and plasma. Its stated purpose was to control misuse of the preparation in equine sport.
The wider thymosin beta-4 literature is broader. The 2005 review covers work on the full protein in dermal and corneal wound models, alongside its biochemistry. Still, those studies concern the 43-residue protein, so they do not transfer automatically to a short fragment. The FDA’s note on missing human exposure data shows how little the fragment itself has been characterised.
That gap shapes how to read any TB-500 research paper. Before you cite a result, check which molecule the authors used. A study on the full protein tells you about the full protein. Likewise, an assay built for the fragment tells you about the fragment.
Reading a TB-500 Research Certificate
For TB-500 research, a certificate answers three separate questions. Is it the right molecule? How clean is it? How much is in the vial? Each needs its own test.
- Purity by HPLC. Bachem’s quality-control guide defines purity as the main peak’s area against the total area of all peaks, read by UV at 210–220 nm. It says nothing about water or salt.
- Identity by mass spectrometry. The instrument weighs the molecule. Because the fragment has 7 residues and the protein has 43, their masses sit far apart, so a mass result settles which one you hold.
- Content. This states how many milligrams of peptide the vial holds. Bachem notes that net peptide content and purity are not the same figure.
- Counter-ion. “Acetate” in a name points to the salt form. Synthetic peptides usually carry acetate or trifluoroacetate, which adds weight that is not peptide.
Our certificate of analysis guide goes through each line in more depth.
The SHLabz TB-500 Certificate
SHLabz publishes one TB-500 certificate so far. It covers batch TB10/2026-0310, a 10 mg vial tested on 19 March 2026 by Janoshik Analytical, an independent laboratory. The report gives 99.833% purity and 10.74 mg of content. Its test number is 122550.
You can check it yourself. Open the report from our lab results page, and it takes you to the record on Janoshik’s own verification site. Then compare the batch number on the report with the label on your vial. If they differ, the certificate does not describe your material. All batch figures are in the open SHLabz Purity Index. Our guide to Janoshik-verified peptides explains the verification step.
The certificate also shows the limits of the name. It prints “TB500 (Thymosin B4 Acetate)”, yet that name alone cannot tell you whether a vial holds the fragment or the full protein. So, in TB-500 research, treat the name as a label and the test data as the evidence.
Handling TB-500 Research Material
TB-500 arrives as lyophilised powder. Kept sealed, dry and out of direct light, that powder is stable at room temperature. Cold storage is possible but not required, although repeated cycling between cold and warm risks condensation inside the vial. After reconstitution, however, the solution belongs at 2–8°C.
Sealed lyophilised powder does not require cold chain. SHLabz holds the whole range to it anyway, because it removes a variable and the handling difference is small.
From Arrival to Working Solution
On arrival, check the seal, the label and the batch number. Then log the date. Next, keep the vial closed until you need it. When you reconstitute, keep the maths in mg/mL. For example, 10 mg in 2 mL of water gives 5 mg/mL, while 10 mg in 5 mL gives 2 mg/mL.
After that, label the vial with the compound, batch, concentration and date. Keep the solution at 2–8 °C, and never freeze it. Our reconstitution guide covers the water and the technique.
A TB-500 Research Checklist
These points turn the sections above into actions for TB-500 research. They describe documentation to look for, not any one supplier.
- Name the molecule. First, decide whether your work needs the fragment or the full protein, and write that down.
- Match the batch. Next, make sure the certificate’s batch number matches the vial label.
- Check identity. Then look for a mass result, not only an HPLC purity figure.
- Check content. Also look for the milligrams of peptide per vial, alongside purity.
- Verify the lab. In addition, confirm the report on the testing lab’s own website.
- Expect a printed label. An unlabelled vial breaks the chain of custody.
- Distrust freezer claims. Sealed powder does not need a freezer, so advice that says otherwise is a warning sign.
- Log everything. Finally, record batch, dates and concentration for each vial you open.
Where SHLabz Fits
SHLabz lists TB-500 as a lyophilised vial, and every UAE order travels with cold-chain delivery. An independent laboratory tests every batch, and its certificate is on the lab results page. TB-500 also appears in the BPC-157 + TB-500 blend and in the KLOW Blend.
The Short Version
In short, thymosin beta-4 is a 43-residue actin-sequestering protein, while TB-500 most precisely refers to an acetylated LKKTETQ fragment from its 17–23 region. Sources still use the two names interchangeably, so check the certificate rather than the label.
Meanwhile, neither molecule holds a marketing authorisation anywhere, and WADA bans thymosin beta-4 at all times. SHLabz supplies TB-500 for laboratory research only.
Frequently Asked Questions
Is TB-500 the same as thymosin beta-4? Not strictly. Thymosin beta-4 has 43 amino acids, while the FDA and a 2012 analytical study tie TB-500 to the seven-residue LKKTETQ fragment. Many sellers and some regulators still use the names interchangeably.
What is the TB-500 sequence? The commonly cited sequence is LKKTETQ with an acetylated N-terminus. It matches residues 17 to 23 of thymosin beta-4, the region linked to actin binding.
Is TB-500 approved anywhere? No. Thymosin beta-4 holds no marketing authorisation anywhere, and SHLabz supplies TB-500 strictly as a laboratory research material.
Is TB-500 banned in sport? Yes. Sport Integrity Australia, citing the 2026 WADA list, places thymosin beta-4 under S2.3 and names TB-500 among its other names.
Why does the SHLabz certificate say Thymosin B4 Acetate? The certificate prints the name as “TB500 (Thymosin B4 Acetate)”, following the naming convention common in this market. Read the identity results on the certificate alongside that name.
Does TB-500 powder need a fridge? No, not while it is sealed, dry and dark. Once you reconstitute it, keep the solution at 2–8 °C and never freeze it.
How can a certificate tell the fragment from the full protein? Through mass spectrometry. A 7-residue fragment and a 43-residue protein differ greatly in mass, so the observed mass shows which one the vial holds.
References
- Doping control analysis of TB-500, a synthetic version of an active region of thymosin β4, in equine urine and plasma by liquid chromatography-mass spectrometry — Ho et al., Journal of Chromatography A, 2012. The acetylated LKKTETQ ingredient and the 17–23 actin-binding site.
- Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues — Goldstein, Hannappel and Kleinman, Trends in Molecular Medicine, 2005. Thymosin beta-4 as the major actin-sequestering molecule.
- Certain Bulk Drug Substances for Use in Compounding — US Food and Drug Administration, updated 2026. The fragment named as TB-500 and the agency’s notes.
- Thymosin Beta-4 — Sport Integrity Australia, substance education page. The 43-residue protein, its approval status and its 2026 WADA category.
- Qatar’s Health Ministry bans trading, use or promotion of unlicensed peptide products — The Peninsula, 27 August 2026. The MOPH circular and its treatment of research labels.
These references describe published research. They say nothing about what any compound does for anybody, and nothing here should read as a claim that it does.
Finally, if you want to compare TB-500 with the blends that include it, the catalogue shows each format and price side by side.
This article is provided for general research and educational purposes only. All SHLabz products are sold strictly for laboratory research use and are not intended for human or veterinary consumption, diagnosis, treatment, or prevention of any disease. Nothing in this article constitutes medical advice. Always consult a qualified professional and comply with applicable local regulations regarding the handling and use of research compounds.
