Name: TB-500
Brand: PeptidesDirect
SKU: PD-TB500-10MG
Price: 44.99 EUR
Availability: InStock

Question 1

What is TB-500?

Accepted Answer

TB-500 is a synthetic version of Thymosin Beta-4, a naturally occurring peptide found in nearly all human and animal cells. It is a 43-amino acid peptide studied extensively in research for its role in tissue repair and cellular migration.

Question 2

How should I store TB-500?

Accepted Answer

Store lyophilized TB-500 at -20°C for long-term storage or at 2-8°C (refrigerator) for short-term use. After reconstitution, keep refrigerated and use within 30 days. Protect from light and avoid freeze-thaw cycles.

Question 3

What purity is your TB-500?

Accepted Answer

Every batch of TB-500 ships with a certificate of analysis from Janoshik Analytical, an independent third-party laboratory, at a minimum purity of 98%. We do not run a lab ourselves: the manufacturer commissions this test, and we pass the report on unchanged, with an online verification link on the product page.

Question 4

How do I reconstitute TB-500?

Accepted Answer

Add bacteriostatic water slowly along the vial wall. Gently swirl to dissolve - never shake. Use 1-2 mL of bacteriostatic water per vial. The solution should be clear before use.

Question 5

Is the TB-500 we sell the full-length 43-amino-acid thymosin beta-4 used in the published research, or the short fragment sold under the same name elsewhere?

Accepted Answer

Our TB-500 is the full-length, 43-amino-acid thymosin beta-4 (molecular mass about 4963 Da, CAS 77591-33-4), the same peptide tested in the studies referenced on this page, not the short Ac-LKKTETQ fragment (amino acids 17 to 23) that some vendors sell under the same trade name. Our current batch-specific CoA (Janoshik, batch Black, tested 17 April 2026) confirms identity at 99.94% purity and 10.09 mg content, consistent with the full-length molecule. The distinction matters because the fragment and the full peptide are structurally different, and most of the published animal and human data, including the cardiac and corneal studies cited below, used the full-length form. A CoA that reports the correct molecular mass, not just a purity percentage, is the only way to know which one is actually in a given vial.

Question 6

How does TB-500 (thymosin beta-4) work, according to the published research?

Accepted Answer

Thymosin beta-4 is an actin-sequestering protein: it binds G-actin, the building block of a cell's internal skeleton, which lets cells change shape and migrate toward damaged tissue. In a mouse model of heart attack, it formed a complex with integrin-linked kinase (ILK) and the adaptor protein PINCH that activated the survival kinase Akt, increasing cardiomyocyte and endothelial cell migration and survival after coronary artery ligation (PMID 15565145). The same actin-handling activity is the proposed basis for the angiogenesis, reduced inflammation, and faster wound closure reported in the skin and corneal studies below. These are cell and tissue-level mechanisms measured in cultured cells and animals, not a description of what happens in a person.

Question 7

What has TB-500 (thymosin beta-4) actually been studied for (condition, model, species)?

Accepted Answer

Published research covers four separate indications, mostly in animals: cardiac protection after a heart attack, tested in mice with a positive result (PMID 25015963), in pigs with a negative result at a higher dose (PMID 27199757), and in human heart-attack patients with an overall-negative phase 2b trial (NCT05984134, PMID 41229390); corneal wound healing after a chemical burn in mice (PMID 11950239); severe dry eye in a small 9-patient human trial (PMID 25826322); and dermal or burn wound healing in rats and diabetic mice (PMID 10469335, PMID 25230158). Each study used its own dose, route, and duration, and the pig and human cardiac results show that the positive mouse finding did not transfer to larger animals or to people.

Question 8

What dose did the TB-500 (thymosin beta-4) studies use (species, route, frequency, duration), and is there a published human dosing protocol?

Accepted Answer

In the mouse heart-attack study, mice received 1.6 mg/kg per day of thymosin beta-4, delivered continuously by intraperitoneal osmotic minipump, for either 7 days or 5 weeks (PMID 25015963); other animal studies used different systemic amounts, from 5 mg/kg intradermally twice weekly for 2 weeks in diabetic mice (PMID 25230158) to 6 mg/kg intravenously in pigs (PMID 27199757). In humans, a 2021 phase 1 trial gave healthy volunteers intravenous recombinant thymosin beta-4 at single doses up to 25 micrograms per kg, or repeated daily doses of 0.5 to 5 micrograms per kg for 10 days (PMID 34346165), and a phase 2b trial gave heart-attack patients 0.5 or 1.0 micrograms per kg intravenously over 7 days after the procedure (NCT05984134, PMID 41229390). Those are the only published human dosing figures for an injectable form of thymosin beta-4, they used a recombinant protein rather than the synthetic peptide sold as TB-500, and the amounts were far lower per kilogram than the systemic doses used in the rodent studies above. A separate human trial used a topical, non-injectable 0.1% eye-drop solution six times daily for 28 days, which cannot be compared on a mg/kg basis (PMID 25826322). No dosing protocol intended for a person to follow has been published for TB-500 itself: what is published are the amounts these specific animal and clinical trials administered, nothing more.

Question 9

What did the TB-500 (thymosin beta-4) studies observe as the outcome, and how quickly did the effect appear?

Accepted Answer

In the mouse heart-attack model, thymosin beta-4 reduced early deaths from cardiac rupture, and after 5 weeks of continuous dosing it had lessened left-ventricular dilation and increased capillary density and cardiac function versus vehicle (PMID 25015963). In the human dry-eye trial, effects were measured at day 56 of a 56-day protocol: a 35.1% reduction in ocular discomfort (P=0.0141) and a 59.1% reduction in corneal fluorescein staining (P=0.0108) versus vehicle (PMID 25826322). In the rat wound model, topical or intraperitoneal thymosin beta-4 increased re-epithelialization by 42% over saline controls by day 4 and up to 61% by day 7 (PMID 10469335). Timeframes therefore ranged from days (skin, cornea) to weeks (cardiac remodeling), and all figures above are what the studies measured in animals or in a 9-patient trial, not a claim about what any vial does for a person.

Question 10

What side effects or adverse events were reported in the TB-500 (thymosin beta-4) studies, with rates and citations where available?

Accepted Answer

The clearest documented signal comes from the pig cardiac study at a high intravenous dose (6 mg/kg): thymosin beta-4 produced vasoconstriction in mesenteric arteries, vasodilation in coronary arteries, and reduced blood clot firmness when combined with an antiplatelet drug (PMID 27199757). The best human safety data comes from a 2021 phase 1 trial in 84 healthy volunteers given intravenous recombinant thymosin beta-4 at single doses up to 25 micrograms per kg: adverse events were mild to moderate, with no serious adverse events or dose-limiting toxicities (PMID 34346165). A separate 9-patient human dry-eye trial of topical 0.1% RGN-259 also reported the treatment as safe and well tolerated, though that abstract does not list specific adverse events or rates (PMID 25826322). None of the mouse or rat wound-healing studies (PMID 25015963, PMID 11950239, PMID 25230158, PMID 10469335) reported any adverse events at all, so their silence reflects what was measured and disclosed, not a demonstrated absence of risk. The only quantified vascular and clotting signal in the literature remains the pig study, at a dose well above both the human IV trial doses and the amounts used in the wound-healing work.

Question 11

What is not known about TB-500 (thymosin beta-4) long-term safety, i.e. what is the honest evidence gap?

Accepted Answer

There is no published long-term human safety data for thymosin beta-4 at any dose or route: the longest completed human trial is a 9-patient, 56-day topical eye-drop study (PMID 25826322), and the only completed trials of an injectable form are a short phase 1 safety study in 84 healthy volunteers, 10 days of dosing (PMID 34346165), and a phase 2b trial in heart-attack patients, 7 days of dosing (NCT05984134, PMID 41229390), that was overall negative on its primary infarct-size endpoint, with a positive signal only in the subgroup that received its first dose within 8 hours. Separately, RegeneRx's own intravenous program (RGN-352) never completed a phase 2 heart-attack trial after a 2011 manufacturing-related clinical hold at its contract manufacturer. A separate 2025 phase 3 trial of the topical eye-drop form (SEER-3) also missed its primary corneal-healing endpoint. In short: no completed trial of an injectable thymosin beta-4 formulation has shown a clear positive result in a general patient population, no long-term human exposure data exists beyond 28 days of dosing, and no regulator anywhere has approved any form of it.

Question 12

Is TB-500 (thymosin beta-4) approved by the FDA, EMA, or any regulator, or is it strictly an unapproved research compound?

Accepted Answer

No. Thymosin beta-4 is not approved by the FDA, EMA, or any other medicines regulator for any indication, in TB-500 form or otherwise. The ophthalmic form (RGN-259) holds US FDA orphan drug designation for neurotrophic keratopathy, granted in December 2013, which speeds up regulatory review but is not a marketing approval, and its most recent phase 3 trial (SEER-3, 2025) missed its primary endpoint. The intravenous systemic form (RGN-352) had its phase 2 program placed on clinical hold in 2011 over a manufacturing (cGMP) issue at the contract manufacturer and was never completed. TB-500 as sold in the research market is not a drug and is not intended for human administration.

Question 13

How does TB-500 compare to BPC-157 in mechanism and evidence, since the two are often studied and sold together?

Accepted Answer

The two peptides work through different mechanisms: TB-500 (thymosin beta-4) acts on the actin cytoskeleton to drive cell migration and angiogenesis, while BPC-157 is proposed to act through growth-factor and blood-vessel-signaling pathways; our BPC-157 research page carries its own PMID-cited evidence for that separate mechanism. TB-500 has a handful of small completed human trials: a 9-patient topical dry-eye study (PMID 25826322), a phase 1 intravenous safety study in 84 healthy volunteers (PMID 34346165), and a phase 2b cardiac trial in heart-attack patients that was overall negative (NCT05984134, PMID 41229390). We have not found a published study that tests the two peptides administered together. The pairing sold as Wolverine is a research-market combination, not one validated by a co-administration trial in the literature reviewed here, and both peptides remain unapproved with no established human dosing protocol for either.

Question 14

Do the published TB-500 (thymosin beta-4) studies actually support a cardiac benefit in humans?

Accepted Answer

Not yet, and the evidence is directly contradictory across species. A mouse heart-attack model found thymosin beta-4 reduced cardiac rupture and improved cardiac function after 5 weeks of continuous dosing (PMID 25015963), but a well-controlled pig ischemia-reperfusion study at a higher intravenous dose found no reduction in cardiomyocyte death and no improvement in cardiac function or blood flow versus control (PMID 27199757). The only trial conducted in heart-attack patients themselves, a phase 2b study of intravenous recombinant thymosin beta-4 in 96 patients (NCT05984134, PMID 41229390, Cardiovascular Research 2025), was overall negative on its primary infarct-size endpoint, with a positive signal only in the subgroup that received its first dose within 8 hours. The positive mouse finding has therefore not been confirmed in either a large animal or the general human patient population.

Question 15

What does our own third-party CoA show for TB-500, and how can a specific batch be verified?

Accepted Answer

Our current TB-500 batch (Black, 10 mg vial) was tested by Janoshik on 17 April 2026 at 99.94% purity and 10.09 mg content, and the report can be checked online at verify.janoshik.com under test 136568. Janoshik is a third-party laboratory, but the test is commissioned and paid for by the manufacturer, not by us, and we publish the report unchanged rather than running our own independent panel on every batch. Two earlier 10 mg batches (White and an earlier Black batch) were also tested by Janoshik, at 99.4% and 99.8% purity respectively, so batch-to-batch purity has stayed in a similar range. If a vial's printed batch code does not match what is currently listed on the product page, the matching report can still be located by contacting support with that code.

Question 16

Is there any published evidence on TB-500 (thymosin beta-4) interacting with blood thinners or antiplatelet drugs?

Accepted Answer

Yes, one study reported it. In the pig ischemia-reperfusion study, a high intravenous dose of thymosin beta-4 (6 mg/kg) reduced blood clot firmness when tested in combination with an antiplatelet agent, alongside vasoconstriction in mesenteric arteries and vasodilation in coronary arteries (PMID 27199757). This is the only published data we found on thymosin beta-4 and clotting or antiplatelet interactions, it comes from a single large-animal study at a dose far above the amounts used in the wound-healing literature, and it has not been studied in humans taking blood thinners. No other study reviewed here measured a bleeding or clotting endpoint.

Question 17

Is combining TB-500 with BPC-157 (the Wolverine stack) based on a published study, or is it a research-market practice?

Accepted Answer

It is a research-market practice, not something tested in a published co-administration trial that we have found. Each peptide has its own separate literature: TB-500's cardiac, corneal, and dermal wound studies are cited throughout this page, and BPC-157 has its own PMID-cited evidence on our BPC-157 research page, but no paper in either set administers the two together and measures a combined effect. The two peptides are proposed to act through different mechanisms, actin-cytoskeleton signaling for TB-500 and growth-factor and vascular signaling for BPC-157, which is the mechanistic rationale offered for combining them, not a demonstrated result. A pre-mixed vial is sold for convenience, but that reflects market demand for the combination, not a clinical or trial basis for it.

Question 18

Has TB-500 (thymosin beta-4) been studied specifically for tendon or ligament injuries, which is a common reason people search for it?

Accepted Answer

There is at least one such study: in rats, a single local dose of 1 microgram of thymosin beta-4, placed directly into a surgically created medial collateral ligament gap via fibrin sealant, produced more evenly organized collagen fibers and significantly better mechanical properties than untreated controls at 4 weeks (PMID 23523891). That is one small rat study using a local, not systemic, dose, evaluated at a single 4-week timepoint. No human tendon or ligament trial has been published for thymosin beta-4, and none of the cardiac, corneal, or dermal studies covered elsewhere on this page extend to tendon or ligament tissue. Tendon and ligament evidence is therefore its own separate, thin category, distinct from the rest of the literature on this peptide.

Question 19

Is TB-500 banned by WADA (or other sports anti-doping bodies), and can it lead to a sanction even without a lab-confirmed positive test?

Accepted Answer

Yes. Thymosin beta-4, sold under the research name TB-500, is named on the World Anti-Doping Agency's Prohibited List under category S2.3 (Growth Factors), a classification it has carried since 2018. Like the rest of category S2, it is banned at all times, in and out of competition, not only on competition day. WADA's code also allows an anti-doping rule violation to be established through non-analytical evidence, such as possession, admissions, or documented records, so a sanction does not always depend on an athlete failing a lab test. This is a sports anti-doping classification, separate from TB-500's legal status here as an unapproved research compound sold strictly for in-vitro laboratory use.

Question 20

How much bacteriostatic water should be used to reconstitute a given TB-500 vial size, and how long does the reconstituted solution stay stable, fridge vs freezer?

Accepted Answer

TB-500 is sold in a 10 mg vial, and it is typically reconstituted with 1 to 3 mL of bacteriostatic water, which gives roughly 3.3 to 10 mg per mL depending on how concentrated the resulting stock needs to be. The water volume only sets that concentration: it does not change the vial's total peptide content or make the dissolved peptide more or less stable. Once reconstituted, keep it refrigerated at 2-8°C, protected from light, and do not freeze it, since freeze-thaw cycles stress a dissolved peptide's structure more than steady refrigeration does. As a conservative guideline consistent with other reconstituted lyophilized peptides we carry, reconstituted TB-500 is best used within about 4 weeks. No published stability study covers reconstituted TB-500 specifically, so this is standard peptide-handling practice, not a validated study finding.

Question 21

TB-500/thymosin beta-4 promotes angiogenesis (new blood vessel growth) as part of its healing mechanism, does that pose a theoretical risk for someone with an active or recent cancer history?

Accepted Answer

The rat dermal-wound study cited above found that thymosin beta-4 enhanced collagen deposition and angiogenesis alongside faster re-epithelialization (PMID 10469335), and the mouse cardiac study attributed part of its effect to increased capillary density (PMID 25015963). Angiogenesis is a normal part of tissue repair, but the wider research literature on angiogenesis-promoting compounds has long noted a theoretical, not demonstrated, concern: that stimulating new blood vessel growth could in principle also support the vascular supply a tumor needs. None of the TB-500 studies referenced on this page were designed to test cancer risk, and none enrolled people with a cancer history, so there is no research finding either way for this specific peptide. This is literature context, not medical guidance: anyone with a personal or family cancer history should raise the question with a physician rather than rely on this page.

Question 22

Is it legal to buy and import TB-500 as a research chemical within the EU, given it is not an approved medicine anywhere?

Accepted Answer

We sell TB-500 explicitly as a laboratory research chemical, not for human or animal use, and that stated research-use framing, matched by how the product is labeled and marketed, is what keeps the sale itself lawful in the EU: it is not sold, marketed, or described as a medicine, so the pharmaceutical approval rules that apply to a licensed drug do not apply to it. That said, we are not a law firm, and this is not country-specific legal advice: import, possession, and research-chemical rules differ across EU member states and can change over time, so we cannot guarantee every country treats an unapproved research peptide the same way. Complying with your own country's import and possession rules when a shipment crosses the border is the buyer's responsibility, not something we can promise on your behalf.

Question 23

Because TB-500 distributes systemically rather than acting locally like BPC-157, does the injection/administration site actually matter for TB-500 the way it's said to for BPC-157?

Accepted Answer

There is real support for that in how the studies are designed, though not from a trial comparing the two peptides directly. In the mouse cardiac study, thymosin beta-4 was infused intraperitoneally (PMID 25015963), well away from the heart, yet its measured effect, higher capillary density and improved cardiac function, showed up in the heart itself, consistent with the peptide circulating and acting at a distance from where it was placed rather than staying local to an injection point. A separate pig study dosed it intravenously (PMID 27199757), systemic by route. We have not found a biodistribution study placing thymosin beta-4 and BPC-157 side by side to compare how localized each is, so this is a route-and-outcome pattern read from TB-500's own animal literature, not guidance on where or how a person should administer anything, a question none of these studies address.

TB-500

What is TB-500

How it works

Often studied alongside

Documentation

Storage and stability

Frequently Asked Questions

Technical data sheet

Frequently bought together

BPC-157

GHK-Cu

KPV

Bacteriostatic Water

Lab Measuring Syringe + Prep Wipes Set (1 mL 31G)

Graduated Measuring Syringe 1 mL 31G x 6 mm

Alcohol Prep Pads 30 x 65 mm

Peptide Storage Box (10 Compartments)

Peptide Vial Case 30 Slots