TB-500 (Thymosin Beta-4)
3 products from 3 brands · free UK delivery · EU 3–7 days
Every TB-500 (Thymosin Beta-4) listing compared
Strength and pack size as stated by each manufacturer. Total milligrams = strength per capsule multiplied by capsules per pack. Price per milligram is calculated from the current price. A dash means the manufacturer does not state that figure.
| Brand | Listing | Strength | Pack | Total | Price | Per mg | Availability |
|---|---|---|---|---|---|---|---|
| Thoroughbred Labs | TB-500 Peptide Capsules | – | 60 capsules | – | £44.99 | – | In stock |
| Yakka Strength | TB-500 Peptide Capsules | – | 60 capsules | – | £54.99 | – | In stock |
| FreeMuscle | TB-500 — Thymosin Beta-4 · 60 Capsules | – | 60 capsules | – | £39.99 | – | In stock |
TB-500, also sold as thymosin beta-4 or Tβ4 and sometimes written TB500, is a synthetic peptide based on the actin-binding region of thymosin beta-4, a 43-amino-acid protein present in almost every cell of the body. It is studied in animal and cell models of wound repair and cell migration, and no version of it is an approved medicine. This page lists every brand of TB-500 stocked at Free Muscle, compared on pack size, form and batch testing, with links to the research and to the certificate for each batch.
What is TB-500?
Thymosin beta-4 is the body's main actin-sequestering protein. By binding G-actin it regulates how cells build their internal skeleton, which in turn affects cell migration, blood vessel formation and the inflammatory response. The product sold as TB-500 is not the full protein. Anti-doping chemists who characterised commercial TB-500 found it to be a short, N-terminally acetylated fragment covering residues 17 to 23 of thymosin beta-4, the segment that carries the actin-binding motif (Esposito 2012). That distinction matters, because most of the published biology concerns the full 43-residue protein rather than the fragment.
Full-length thymosin beta-4 has been taken into early human trials for dry eye and wound indications by a US biotechnology company, but nothing has been approved and the fragment sold as TB-500 has no human trial data at all. It is not a licensed medicine in the UK, the EU or the United States. Thymosin beta-4 and its derivatives, with TB-500 named as an example, are prohibited at all times under WADA class S2 (peptide hormones, growth factors and related substances).
What the published research reports
A 1999 study reported that topical or intraperitoneal thymosin beta-4 accelerated closure of full-thickness skin wounds in rats, with increased collagen deposition and keratinocyte migration (Malinda 1999). A 2004 study in Nature reported that thymosin beta-4 activated integrin-linked kinase, promoted cardiac cell migration and survival, and improved cardiac function after experimentally induced myocardial infarction in mice (Bock-Marquette 2004). A 2005 review summarised the protein's actin-sequestering role and its wound-repair activity across animal models (Goldstein 2005). All of this used the full protein, in animals, at doses and routes with no relation to any capsule product, and none of it has been confirmed in a completed human efficacy trial.
The other body of literature is analytical. Doping-control laboratories have published methods for detecting TB-500 and its metabolites in equine urine and plasma, and the same approaches are applied in human sport (Ho 2012). None of the above is a claim about any product on this page.
- Malinda KM, et al. Thymosin beta4 accelerates wound healing. J Invest Dermatol. 1999;113(3):364-368. PMID: 10469335.
- Bock-Marquette I, et al. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-472. PMID: 15565145.
- Goldstein AL, Hannappel E, Kleinman HK. Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues. Trends Mol Med. 2005;11(9):421-429. PMID: 16099219.
- Esposito S, et al. Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500. Drug Test Anal. 2012;4(9):733-738. PMID: 22962027.
- Ho EN, et al. 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. J Chromatogr A. 2012;1265:57-69. PMID: 23084823.
Brands of TB-500 we stock
- Free Muscle TB-500 Thymosin Beta-4, 60 capsules. Free Muscle brand, capsule form, 60 capsules per pack. Every batch is assayed by Janoshik Analytical and the certificate for the batch you hold is sent on request.
- Thoroughbred Labs TB-500 Peptide Capsules. 60 capsules. No per-capsule quantity is published by the manufacturer. A COA is shown where Thoroughbred Labs supplies one for the batch we hold.
- Yakka Strength TB-500 Peptide Capsules. 60 capsules. No per-capsule quantity is published by the manufacturer. A COA is shown where Yakka Strength supplies one for the batch we hold.
- Free Muscle Recovery Stack (BPC-150, TB-500 and PCT) (not listed at the moment; see other bundles and stacks). A Free Muscle bundle that includes the TB-500 capsules above as a separate product with its own batch certificate.
How to compare them
Where a strength per capsule is published, multiply it by the capsule count to get total milligrams and divide the price by that number for cost per milligram. Where no strength is published, as with two of the brands here, the honest comparison is on documentation: whether an independent laboratory has tested the exact batch on sale, and whether the certificate names the batch number, the method and the purity found. Ask for the certificate before you buy rather than after.
Batch testing and certificates of analysis
A certificate of analysis (COA) is a laboratory report tied to one manufactured batch. It records the identity of the compound tested (usually by HPLC or LC-MS against a reference standard) and the purity found, and it carries the batch number, the test date and the name of the laboratory that ran the assay. Every Free Muscle-brand batch is assayed by Janoshik Analytical, an independent laboratory, and we will send the certificate for the batch you hold if you email us with the batch number from the label. For the other brands on this page (Thoroughbred Labs and Yakka Strength) a COA is shown only where the manufacturer has supplied one for the specific batch we hold, and we leave the field blank rather than imply a test that does not exist.
A generic PDF with no batch number, no date or no named laboratory is not a batch certificate, whatever it is called. Match the batch number on the certificate to the number on your pack before relying on it. Our lab tests page explains what to look for.
Legal status in the UK
TB-500 is not a licensed medicine in the UK and has no MHRA marketing authorisation. It is not an authorised food supplement and may not be sold for human consumption. It is supplied for laboratory research to adults aged 18 and over and is not a controlled drug. In sport it is prohibited at all times under WADA class S2, which names thymosin beta-4 and its derivatives, including TB-500, explicitly. For background on how peptides and SARMs are classified, see our SARMs versus peptides guide.
Storage and handling
Keep the container sealed, in a cool, dry place away from direct light, and return it there each time the container has been opened. Do not decant into unlabelled containers. Keep out of the reach of children and animals. Handle in line with ordinary laboratory good practice, with gloves and a clean work surface, and dispose of unwanted material through an appropriate waste route rather than down the sink.
Delivery and returns
Free Muscle is a UK company (FreeMuscle LTD, Scunthorpe). Every order ships with free tracked UK delivery in plain packaging with nothing on the outside to say what is inside. Orders placed before 2pm Monday to Friday are processed the same working day. EU delivery takes three to seven working days. Unopened items can be returned within 30 days. Customers must be 18 or over. Full details are on our shipping page and our guarantee page.
Related reading
- Do oral peptides actually work? The honest answer
- BPC-157: what the research actually shows, and what it does not
- How to read a certificate of analysis
- Price per milligram: the only honest way to compare
- BPC-157, BPC-150, all peptides and IGF-1 LR3
TB-500 is supplied for laboratory research use only. It is not a licensed medicine, not a food supplement and not for human consumption. Nothing on this page has been evaluated by the MHRA, EMA or FDA, and nothing on this page is medical, health or dosing advice. Sales are restricted to adults aged 18 and over.
Research guides
Frequently asked questions
Is TB-500 legal in the UK?
TB-500 can be legally bought and held in the UK for research; it is not a controlled drug. What it cannot be is sold as a medicine or a supplement, because the MHRA has never licensed it and no food regulator has authorised it, so it is not for human consumption. We supply it to adults aged 18 and over for laboratory use. In sport it is prohibited at all times under WADA class S2, which names TB-500 specifically.
Is TB-500 the same as thymosin beta-4?
Not exactly. Thymosin beta-4 is a 43-amino-acid protein found in most cells. Commercial TB-500 has been characterised by anti-doping chemists as a short, acetylated fragment covering residues 17 to 23, the actin-binding segment. Most published biology concerns the full protein, so results on thymosin beta-4 do not automatically apply to the fragment.
Is TB-500 a peptide or a SARM?
A peptide. TB-500 is a short amino-acid sequence taken from thymosin beta-4, and its known biology concerns binding actin inside cells. It has no relationship to SARMs, which are synthetic non-peptide compounds designed around the androgen receptor. Any page that groups the two together is grouping them commercially rather than scientifically.
What is the difference between TB-500 and BPC-157?
Both are peptides studied in animal models of tissue repair, but they are unrelated sequences. BPC-157 is a fifteen-amino-acid fragment from a gastric protein; TB-500 is a fragment of thymosin beta-4, an actin-binding protein. Neither has a completed controlled human trial, and neither is an approved medicine anywhere.
Is TB-500 detectable in sport drug tests?
Yes. Published doping-control methods detect TB-500 and its metabolites by liquid chromatography-mass spectrometry, originally developed for equine testing and applied in human sport. Since it is prohibited at all times under WADA class S2, a tested athlete should expect it to be found.
How do I verify the batch of TB-500 I receive?
Free Muscle TB-500 is assayed batch by batch at Janoshik Analytical, an independent laboratory; email us the batch number from your label and we will reply with that batch's certificate. Thoroughbred Labs and Yakka Strength TB-500 carry a manufacturer certificate on the product page only when one has been supplied for the batch in stock. In either case, a document without a batch number, a test date and a named laboratory is not evidence of testing.
Which TB-500 strength should I choose?
We leave that decision to the researcher and give no guidance on it. TB-500 is sold for laboratory research and this page describes the listings, not how to use them. What we can state is factual: pack size, form, whether the brand publishes a per-capsule figure at all, and what batch documentation exists. Two of the three brands here publish no strength, which limits any comparison to documentation.
How is TB-500 shipped and can I return it?
We send every parcel by tracked delivery, free of charge within the UK, in unmarked packaging. Same-working-day processing applies to orders placed before 2pm Monday to Friday. EU customers should allow three to seven working days. Our returns window is 30 days and covers unopened items only. Buyers must be aged 18 or over, and the full terms are on our shipping and guarantee pages.