TB-500 is a synthetic version of the naturally occurring peptide thymosin beta-4, aka timbetasin. Research on TB-500 usually refers to it as synthetic thymosin beta-4.
Human studies on TB-500 are lacking, but the peptide is the subject of active research due to the regenerative properties of thymosin beta-4.
Thymosin beta-4 is found in every cell in the human body except erythrocytes, and is thought to play a role in angiogenesis, wound healing, and cell proliferation, differentiation, and migration.
For researchers looking to incorporate TB-500 into their work, this guide provides the latest information on TB-500′s mechanism of action, uses, and side effects.
We also include details on how to dose and administer TB-500 in research settings, as well as where to source 99% purity TB-500 online.
What is TB-500?
TB-500 is a synthetic form of thymosin beta-4 (TB4), an endogenous human peptide that is made of 43 amino acids and can be found in virtually all cells of the body, especially in platelets and white blood cells [1]. TB4 was first isolated in 1981 by Low and Goldstein from bovine thymus gland extract [2].
The synthetic version, TB-500, has not been approved for human use and is available solely as a research chemical. It was first manufactured in the early 2010s for veterinary use. TB-500 has been used as a doping agent in horse racing and consecutively banned for providing an unfair advantage in that sport [3, 4].
Thymosin beta-4 and its derivatives, including TB-500, are likewise banned by the World Anti-Doping Agency (WADA) and thus prohibited for use by competitive athletes subject to the WADA Code and comparable national and regional regulatory bodies [5].
TB-500 is nonetheless under active research for its potential effects on cell migration and tissue repair, formation of new blood vessels, maturation of stem cells, survival of various cell types, and anti-inflammatory action [1, 6].
TB-500 and thymosin beta-4 have poor oral bioavailability, and thus can only be administered via injections in experimental settings.
Yet, a naturally occurring fragment of thymosin beta-4, called N-acetyl seryl-aspartyl-lysyl-proline (Ac-SDKP), is an orally active peptide thought to possess similar antifibrotic, anti-inflammatory, angiogenic properties, and effects on cell migration and survival [7, 8].
It has been investigated as an inhibitor of hematopoietic stem cell proliferation and a chemoprotective agent [9, 10]. Researchers may find the TB-500 fragment included in innovative TB-500 capsule formulas intended for tissue repair and recovery.
(Peptides.org, sponsored) TB-500 peptide therapy: uses, dosage, and safety
What Does TB-500 Do?
The mechanisms of action of TB-500 are still under investigation, but scientists already have some insight into the workings of its natural counterpart, thymosin beta-4.
Thymosin beta-4 appears to work as an actin-binding protein that inhibits the polymerization of globular actin (G-actin) into filamentous actin (F-actin) [11, 12]. The process is called actin sequestration and results in upregulated G-actin levels [13].
Actin is a major component of the cellular cytoskeleton that provides structural support to cells and is involved in various cellular processes, including cell motility. Thymosin beta-4 appears to bind with actin primarily (but not only) via its central actin-binding domain (aa 17-23), also known as Ac-LKKTETQ [14].
The prevention of F-actin polymerization by thymosin beta-4 alters the cellular cytoskeleton, which affects the ability of cells to move and change shape. This process has implications for various physiological and pathological processes where cell motility is crucial, such as wound healing, tissue regeneration, and cancer metastasis [15].
In addition, thymosin beta-4 can be found outside of cells (extracellularly) in blood plasma or in wound fluid. Research in blood vessel cells suggests that the application of extracellular thymosin beta-4 may also regulate processes such as cell motility and angiogenesis. It was found to act extracellularly by interacting with cell surface-located ATP synthase enzymes, cellular enzymes involved in the energy production of the cell [16, 17].
Extracellular thymosin beta-4 may also get oxidized in sites of inflammation to thymosin beta-4 sulfoxide, and the latter is thought to have potent anti-inflammatory properties [18].
Thymosin beta-4 may likewise reduce inflammation by increasing the expression of microRNA-146a (miR-146a), thought to decrease the expression of two pro-inflammatory cytokines called L-1 receptor-associated kinase 1 (IRAK1) and tumor necrosis factor receptor-associated factor 6 (TRAF6) [19].
TB-500 Benefits | State of Research
Research on TB-500 and its natural counterpart, thymosin beta-4, is still in the early stages.
Limited clinical trials available, and the majority of studies are laboratory experiments performed in vitro or in test animals.
With that in mind, explore some of the potential benefits associated with TB-500 and thymosin beta-4.
TB-500 for Wound Healing
Due to its potential effects on cell migration, TB-500 has been proposed to facilitate the mobilization and differentiation of progenitor cells, which may speed up the healing of wounds in various tissues, including the skin, blood vessels, and cornea.
Among the few trials conducted in human subjects was a double-blind, placebo-controlled, dose-escalation study involving 73 patients with venous stasis ulcers given local thymosin beta-4 for 84 days.
The trial was conducted across eight European sites, and upon analysis of the results, the researchers reported that the peptide was safe and well-tolerated, with a placebo-comparable safety profile.
Efficacy results from this phase-2 study suggest that a topically administered thymosin beta-4 dose of 0.03% has the potential to accelerate wound healing, having achieved complete wound healing within three months in approximately 25% of patients. It was further reported to decrease the median time to healing by 45% among those whose wounds completely closed [20].
Another phase-2 study examined the effect of thymosin beta-4 as an ophthalmic solution in 72 subjects with moderate to severe dry eye receiving either 0.1% TB4 or a placebo for 28 days.
Damage to the eye cornea related to the dry eye syndrome was measured via corneal staining. The results showed significant improvements in central and superior corneal staining, while no side effects were reported [21].
Similarly, a 56-day phase-2 clinical trial included nine patients with severe dry eye who were treated with either thymosin beta-4 ophthalmic solution or placebo for 28 days, followed by a 28-day follow-up.
At day 56, the six patients taking thymosin beta-4 demonstrated a 35.1% reduction in ocular discomfort compared to a 59.1% reduction in total corneal fluorescein staining compared to the control group [22].
A trial by the same researchers also reported that thymosin beta-4 as an ophthalmic solution was applied to nine patients with chronic nonhealing neurotrophic corneal ulcers and reported that amongst six of the patients who had geographic corneal defects, there was significant healing without neovascularization [23].
TB-500 for Muscle Recovery
Scientists have reported increased expression of thymosin beta-4 in murine models of skeletal muscle injury and regeneration, especially in the early stages.
Notably, the peptide has been found to contribute to wound healing and promotes chemotaxis of myoblasts, accelerating wound closure. Its sulphoxide form is particularly effective in attracting myoblasts derived from muscle satellite cells, facilitating skeletal muscle regeneration [24].
Clinical studies have also investigated the effects of thymosin beta-4 in repairing cardiac muscle rather than skeletal muscle tissue.
In one clinical trial, researchers aimed to investigate the role of thymosin beta-4 in patients with ischemic cardiomyopathy who were receiving intracardiac injections of bone marrow-derived stem cell (BMSC) therapy. There were 13 patients and 14 controls included.
The results showed a significant increase in plasma thymosin beta-4 levels 24 hours after intracardiac injection of BMSCs. Moreover, the increase in TB4 levels was associated with an improvement in the patients’ symptom score and severity [25].
Another clinical trial investigated the effect of thymosin beta-4 pre-treated endothelial progenitor cell (EPC) transplantation via an intravascular catheter in patients with acute myocardial infarction (STEMI).
Ten patients with STEMI were included and randomly assigned to two groups: a EPC transplantation group (control) and a thymosin beta-4 pre-treated EPC transplantation group.
After six months of follow-up, the experimental group showed a significant increase in average six-minute walking distance compared to the control group. Additionally, the thymosin beta-4 group exhibited significant improvement in cardiac function compared to the control group, without any severe complications noted [26].
TB-500 for Reducing Inflammation
As previously noted, thymosin beta-4 and especially its oxidized form provide potent anti-inflammatory benefits when acting extracellularly [18].
In one experiment, researchers used a murine model of liver injury to investigate the potential effects of thymosin beta-4 on inflammation and oxidative stress.
The results showed that one week of intraperitoneal thymosin beta-4 injections reduced markers of liver injury and prevented changes in liver pathology.
TB4 decreased reactive oxygen species (ROS) and lipid peroxidation while increasing antioxidant levels. It inhibited the activation of nuclear factor kappa B, thus suppressing pro-inflammatory cytokine production and preventing liver fibrosis [27].
Scientists have also hypothesized that the peptide may provide benefits in clinical trials with patients suffering from non-alcoholic fatty liver disease (NAFLD), although no research has investigated this potential in humans [28].
TB-500 Side Effects
As of writing, there has been no consensus among researchers as to what, if any, side effects may occur from administering TB-500. This is due primarily to the notable lack of clinical research on the adverse effects of TB-500 or thymosin beta-4.
One of the few trials on the topic was published in 2010 and included 10 healthy volunteers. The study reported that the side effects of synthetic thymosin beta-4 were infrequent, and mild to moderate in intensity [29].
There were only a few cases of headache, dizziness, and feverish feelings that were deemed to potentially be associated with thymosin beta-4. There were no dose-limiting toxicities or serious adverse events reported.
The study found that synthetic TB4 was well-tolerated when administered intravenously as a single dose or in multiple daily doses for 14 days at a dose range of 42-1260mg. Despite these high doses, no clinically significant findings were observed in vital signs, ECG evaluations, or physical exams [29].
A more recent trial included 54 healthy participants and also reported no serious side effects after 10 days of intravenous thymosin beta-4 administration.
The cohorts received ascending doses ranging from 0.05-25.0mcg/kg in a single-dose trial, and then 30 of the subjects were randomly enrolled in the multiple-dose trial receiving 0.5, 2.0 and 5.0μg/kg daily for 10 days with a 28 day follow-up. There were only mild to moderate adverse reactions with similar incidence and severity in both the treatment and control groups [30].
Researchers should also note that the process of administering TB-500 via injection may lead to local side effects. These may include injection site pain, reddening, bleeding, and inflammation.
(Peptides.org, sponsored) TB-500 peptide therapy: uses, dosage, and safety
Is TB-500 Safe?
Researchers should keep in mind that neither TB-500 nor thymosin beta-4 have been evaluated for safety by the United States Food and Drug Administration (FDA) or comparable regulatory body.
Any statements or findings related to TB-500 should thus be approached with caution.
Further, researchers should remember to exercise proper care when administering TB-500 to test subjects, as with any experiment involving research peptides.
Nonetheless, all published pre-clinical and clinical studies involving TB-500 and thymosin beta-4 have shown limited incidence of only mild to moderate adverse effects, which have not differed significantly from placebo.
TB-500 Dosage Calculator and Chart
It’s worth noting that due to the lack of published research on TB-500, there are currently no specific dosage recommendations for research purposes.
The available research primarily involves animal models or test subjects, and the findings from these studies cannot be directly applied to humans.
The limited human studies conducted with injectable thymosin beta-4 report TB-500 dosing that varies greatly and administered at a maximum duration of 14 days. There are no clinical studies involving TB-500 peptide therapy courses longer than two weeks [29, 30].
Alternatively, thymosin beta-4 has also been effectively used topically in clinical trials at concentrations of 0.03% for over three months. Topical use has also shown excellent safety and tolerability [20].
Based on current information, TB-500 injections for injury recovery may be administered based on the following schedule:
For more detailed information on TB-500 dosing, see our detailed TB-500 Dosage Calculator and Chart.
Where to Buy TB-500 Online?
When procuring TB-500 online for research purposes, peptide buyers should meticulously assess different vendors in regards to pricing, dependability, customer reviews, product quality, accepted payment methods, and the level of customer service offered.
Based on our extensive experience, we wholeheartedly endorse Limitless Life as a reliable source for research-grade TB-500. Their track record of consistently delivering quality products makes them an excellent choice for researchers seeking TB-500 online.
This supplier offers a plethora of advantages that include:
How to Reconstitute TB-500
Injectable TB-500 is commonly shipped in the form of lyophilized powder that needs to be reconstituted with a sterile solvent. While sterile water can be used, most researchers instead opt for bacteriostatic water, which contains 0.9% benzyl alcohol to prevent microbial growth.
After reconstitution with bacteriostatic water, the peptide may be administered for up to four weeks. On the other hand, if sterile water is used, the reconstituted peptide is only usable for 24 hours, even when refrigerated, as sterile water does not inhibit microbial growth.
To reconstitute TB-500 correctly, researchers will need the following materials:
After obtaining all materials needed for reconstitution, follow the following guidelines on how to reconstitute TB-500:
If available, use sonication or let the TB-500 vial rest. Avoid forceful tapping or shaking, as this can damage the peptide structure. Also, avoid tapping the syringe before injection.
Check the clarity of the liquid and look for any particles. If the solution is cloudy, discard it. Lastly, remember not to freeze reconstituted peptides, as this damages the peptide and may render it inactive regardless of the solvent used.
TB-500 Injections | A-Z Guide
According to the available research, injectable TB-500 has been studied in a variety of ways, including intravenous and intraperitoneal applications.
One of the easiest and safest ways to apply peptides for research is the subcutaneous route. Researchers who plan on using reconstituted peptides for research should familiarize themselves with the proper technique for subcutaneous administration:
By following these guidelines, researchers can safely conduct experiments with research peptides such as TB-500.
(Peptides.org, sponsored) TB-500 peptide therapy: uses, dosage, and safety
Is TB-500 Legal?
TB-500 is not approved for human use. The peptide is a research chemical strictly intended for laboratory experimentation. It is legal to buy and possess only for a researcher or qualified laboratory professional who intends to use it in in vitro experiments.
Since the majority of research on thymosin beta-4 and TB-500 is currently in the preclinical stage, and clinical research is scarce, the peptide should not be procured or used for personal use.
As mentioned, the peptide is currently banned by WADA as well as in competitive horse racing.
WADA categorizes TB-500 as a prohibited substance in class S2, which includes growth factors and growth factor modulators. According to this prohibition, athletes should avoid the peptide at all times, including in and out of competition, training, and off-season [5].
TB-500 | FAQ
How to take TB-500
TB-500 is administered to test subjects via injection. Animal and human studies report subcutaneous, intramuscular, and intravenous administration. It has also been applied topically and as pre-treated implants. The TB-500 fragment Ac-SDKP is also included in capsule-based formulations.
How is TB-500 delivered?
TB-500 for research purposes typically comes as lyophilized powder in sterile vials that require reconstitution before administration to test subjects.
Does TB-500 increase testosterone?
No, there is no data to suggest that TB-500 increases or affects testosterone levels.
Does TB-500 build muscle?
No, there is no data to suggest that TB-500 stimulates muscle building, but it may stimulate muscle tissue regeneration.
Does TB-500 cause weight gain?
No, there is no data suggesting that TB-500 causes weight gain.
Is TB-500 a steroid?
No, TB-500 is not a steroid and does not possess any similarities with anabolic-androgenic steroids in terms of structure or mechanisms of action.
TB-500. Just. Works.
TB-500 is a synthetic version of thymosin-beta 4, a protein that occurs naturally in almost all human and animal cells and plays key roles in cell migration, differentiation, tissue repair, angiogenesis, and managing inflammation.
The potential benefits of TB-500 include muscle regeneration, wound healing, anti-inflammatory benefits, and more! Extensive human studies are lacking, as research on this compound is still in its early stages.
It is banned by WADA for use in competitive athletics and prohibited in competitive horse racing due to its perceived performance-enhancing effects.
Qualified scientists who plan to use TB-500 in in vitro testing may legally obtain it as a reference material.
To ensure product quality and consistency, we recommend purchasing TB-500 from a reputable source like Limitless.