Dashnaiv Peptides
Compounds·repair & anti inflammatory·thymosin beta-4 fragment; actin sequestration, angiogenesis

TB-500: what the thymosin beta-4 trials show, what the injected fragment has never been tested for, and its status

What 1,257 indexed publications and 7 randomized trials actually state about tb-500, sentence by sentence, each tied to its source and labeled by the kind of evidence it is.

Human clinical trial Reviewed 51 sources Updated

At a glance

Evidence availability
Human clinical evidence
Strongest tier in the indexed literature
Indexed publications
1,257
Europe PMC, title or abstract, 2026-09-14
Human studies in ledger
14
6 randomized; study count, not efficacy proof
Approval
none found
no registered development programme
Routes reported
intravenous, oral, topical
from studies in this ledger
Studied in
Humans, Mice, Rats
24 primary studies in the evidence table
Reviewed by Adam Mirando, PharmD, on . What changed

What TB-500 is and how it acts

TB-500 is a peptide in the repair & anti inflammatory class (thymosin beta-4 fragment; actin sequestration, angiogenesis). Europe PMC indexes 1,257 publications naming it or a listed alias in a title or abstract, including 7 randomized controlled trials and 6 clinical trials of any design, as of . The strongest evidence tier in that literature is human clinical trials.

This page reports what those studies state, sentence by sentence, with each statement tied to its source and labeled by the kind of evidence it is. It does not recommend use, and it does not translate study doses into anything personal.

What the evidence level means

Publication counts show what is indexed, not how strong the evidence is. The ledger below separates human clinical records from preclinical, analytical, and in-vitro work.

Human clinical studies in this ledger146 randomized · 8 other human clinical
Evidence strengthNot yet assessedSeparate from evidence availability
Efficacy signalNot yet assessedRead the study result, not the tier alone

Interpretation boundary: An indexed publication count is a discovery measure. It does not establish efficacy, safety, approval, or a personal treatment plan.

TB-500 in two minutes

What it is. Usually a seven-amino-acid fragment of thymosin beta-4, a protein in nearly every cell that regulates actin and cell movement. Some products sold as TB-500 are the full 43-amino-acid protein.

What the research actually shows. 1,257 indexed publications because the protein is a basic cell-biology molecule. Human trials exist for the full protein: eye drops for dry eye and corneal disease, a topical gel for chronic wounds, and an intravenous safety study in 40 volunteers. For the injected fragment: one rat tendon study, shared with BPC-157. No human trial.

Status. Not approved anywhere; WADA S2, prohibited at all times; under FDA compounding review in 2026.

Where the evidence is thinnest. Whether injecting the fragment does anything the full protein does, and everything about it in people.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

How TB-500 and thymosin beta-4 work

Written from general pharmacology and the development record, and marked as editorial synthesis; the measurements behind it are quoted in the biomarker section.

  • Thymosin beta-4 is a 43-amino-acid protein present in almost every human cell, where it binds actin and regulates how cells build their skeleton and move. What is sold as TB-500 is usually a short synthetic fragment, seven amino acids from the protein's actin-binding region (positions 17 to 23), although some vendors sell the full protein under the same name. This page's ledger indexes both under the compound's aliases, and the distinction matters for every sentence about evidence.Editorial synthesis
    Editorial synthesis from general knowledge
  • The proposed healing mechanism follows from actin biology: by binding actin, thymosin beta-4 promotes the migration of cells into a wound, encourages new blood-vessel formation, reduces inflammation and scarring, and in heart-attack models in animals protects cardiac muscle. These effects are documented for the full protein in animals and cells; whether the seven-amino-acid fragment reproduces them when injected has been tested in very few studies.Editorial synthesis
    Editorial synthesis from general knowledge
  • The human evidence belongs to the full protein, developed by RegeneRx under the names RGN-259 (eye drops), RGN-137 (topical gel) and RGN-352 (intravenous). Those trials span dry eye and neurotrophic keratopathy, chronic wounds and epidermolysis bullosa, and a phase 1 intravenous safety study in healthy volunteers. No trial has tested injected TB-500 fragment for any indication; the one indexed study of injected TB-500 for healing is the 2026 rat tendon study that also tested BPC-157.Editorial synthesis
    Editorial synthesis from general knowledge

What did the studies find?

Reported outcomes, almost all for the full protein. The injected fragment has one rat study. One row per primary study in this record's ledger. Fields are read from each paper's indexing and abstract. "Analytical method" marks papers about detecting or measuring the compound rather than about its effects.

24 primary studies in this record's ledger, strongest evidence first. A dash means the abstract did not state the value.
StudyDesignnSpeciesDoseRouteDurationReported outcomeTier
Wang 2021 Randomized controlled trial — Humans—intravenous10 days; 28 days The plasma concentration, maximum peak concentration (C max ) and AUC of each dose group increased with the increase in the dose. Human clinical trial
Pathak 2020 Clinical trial — Humans——— A subset model of 4 variables (kerosene uses, ventilation, workplace, and gender) based on significant AOR was adjudged acceptable for estimating the probability of TB incidences. Human clinical trial
Zhu 2016 Randomized controlled trial 5 Humans——6 months After 6 months of follow-up, the average 6-min walking distance was increased by 38.2 m (from 263 ± 42 m to 302 ± 34 m) in the control group and 75.7 m (from 264 ± 42 m to 340 ± 44 m) in the experimental group; the… Human clinical trial
Sosne 2015 Randomized controlled trial — Humans——56 day; 28 day Statistically significant differences in both symptom and sign assessments, were seen at various time points throughout the study. Human clinical trial
Ruff 2010 Randomized controlled trial — Humans——14 days Pharmacokinetic profile for single dose showed a dose proportional response, and an increasing half-life with increasing dose. Human clinical trial
Guarnera 2010 Randomized controlled trial 73 Humans——— Thymosin beta 4 (Tbeta4), a synthetic copy of the naturally occurring 43 amino-acid peptide, has been found to have wound healing and anti-inflammatory properties, and is thought to exert its therapeutic effect through… Human clinical trial
Guarnera 2007 Randomized controlled trial 72 Humans—topical84 days; 14 days The study is ongoing and a total of 21 patients have been enrolled so far in the first treatment group at the lower dose. Human clinical trial
Uyy 2026 Human study — Humans——— In diabetic ischemic mice, TLR4 inhibition was associated with altered abundance of several circulating proteins, including reductions in selected amyloid-associated proteins. Observational, human
Simiczyjew 2026 Human study — Humans——— Among the proteins secreted in significantly higher amounts by resistant cells (compared to the control group), which may be potential biomarkers or therapeutic targets in melanoma, plasminogen activator inhibitor 1,… Observational, human
Zhang 2025 Human study 43 Humans——7 day; 28 days In a randomized, placebo-controlled, double-blind trial involving 96 STEMI patients, the infarcted areas were significantly reduced in the rhTB4 group, which received the first dose of rhTB4 within 8 h after PCI (n =… Observational, human
Li 2025 Human study — Humans——— — Observational, human
Li 2024 Human study — Humans——— Tβ4 enhances adipose viability in AFG via facilitating ADSC proliferation and reducing apoptosis, and acts as a crucial positive regulator of ADSC-associated angiogenesis. Observational, human
Zhang 2021 Observational study 64 Humans——7 days; 28 days Lower Tβ4 stages were correlated with poor prognosis, including AKI(odds ratio [OR], 2.102 per stage lower; 95% confidence interval [CI], 1.448 to 3.050; P Conclusions Lower Tβ4 stages are associated with higher odds… Observational, human
Drum 2017 Human study 219 Humans——— Stratifying by sex, only women (1623 [1040-2625] ng/mL versus 942 [386-1891] ng/mL, P P =1.0), had significantly elevated TB4 in the setting of HFpEF. Observational, human
Biçer 2026 Animal study — Rats60 µg/kg/day—— Biomechanical testing revealed higher maximum load to failure values in the BPC-157 and TB-500 groups compared to controls, reaching statistical significance in the TB-500 group (p Conclusion In this exploratory rat… Animal, preclinical
Zhao 2026 Animal study — Mice—oral— Conversely, oral administration of recombinant human Tβ4 (rhTβ4) significantly improved survival, alleviated body weight loss, reduced epithelial injury, and suppressed inflammatory cytokine production in both… Animal, preclinical
Banga 2026 Animal study — ———— Although Tβ4 improved wound healing and barrier function, the disruptive effects of CPFX were not fully mitigated. Animal, preclinical
Ebrahim 2026 Animal study 6 Mice——— Adjunctive Tβ4 + ciprofloxacin treatment markedly improved visual acuity and contrast sensitivity and significantly enhanced corneal sensitivity and nerve regeneration compared with PBS, Tβ4, and ciprofloxacin… Animal, preclinical
Liang 2026 Animal study — Mice——— — Animal, preclinical
Keplinger 2026 Animal study — ———— Consistent with these findings, we demonstrate that IPO9 modestly decreases the rate of actin filament assembly, a process that requires both actin faces, and that IPO9 exhibits minimal binding to actin filaments. Animal, preclinical
Nguyen 2025 Animal study — Mice——— In vitro, tTB4 promoted increased hTCEpi viability and migration compared to TB4. Animal, preclinical
Zeng 2025 Animal study — Mice——— Interestingly, the expression level of the gene TMSB4X that encodes thymosin beta 4 (Tβ4) significantly decreased both in fAD organoids' neurons and AD patients' excitatory neurons. Animal, preclinical
Maar 2025 Animal study — Mice——— Our results revealed a significant increase in miR139-5p expression and identified ROCK1 as a potential target protein aligned. Animal, preclinical
Chen 2025 Animal study — Rats, Mice——— Furthermore, single-cell sequencing revealed a distinct subset of pro-inflammatory and pro-fibrotic corneal epithelial cells in the dry eye model, while glutamine treatment downregulated those subclusters, thereby… Animal, preclinical

Doses reported in studies

Each entry is a sentence quoted from the study's abstract, with the study's design, sample size and year in front of it. Comparator doses in the same sentence are not attributed to tb-500.

  • Animal study rats 2026 Animal, preclinical
    Doses stated in the abstract: 60 µg/kg/day
    Thirty-two male Sprague-Dawley rats, each aged 12 weeks and weighing approximately 330 g, underwent standardized Achilles tendon transection and repair and were randomly assigned to four groups, with eight rats in each group: control, BPC-157 (10 µg/kg/day), TB-500 (60 µg/kg/day), and combined BPC-157 + TB-500 (BPC + TB).
    Source pmid-42542926 · quoted verbatim from the abstract, emphasis added

TB-500 and thymosin beta-4 doses in studies

Almost every human figure is for the full protein by eye drop, gel or intravenous infusion. Injected fragment doses exist only in one rat study.

StudyDose and routeDurationFinding
Intravenous phase 1, full protein (Ruff 2010)42 to 1,260 mg, single then daily14 days40 healthy volunteers; no dose-limiting toxicity
Intravenous pharmacokinetics, full protein (Wang 2021)Escalating single dosesSingleExposure rose with dose
Eye drops, RGN-259 (Sosne 2015 and later trials)0.1% dropsWeeksSymptom and sign improvement in dry eye and neurotrophic keratopathy
Topical gel, RGN-137 (Guarnera 2007, 2010)Dose-ranging gelWeeksPressure ulcers and epidermolysis bullosa wounds; dose-ranging
Small cardiac study (Zhu 2016)Not stated in abstract6 months follow-up5 patients; walking distance increased; uncontrolled
Rat Achilles tendon (Biçer 2026)60 µg/kg/day, injectedWeeksHigher load to failure vs controls; also tested with BPC-157

Figures for this compound circulate on forums and vendor pages. None has been tested in a human study, so none is reproduced here; the table above holds every dose a study actually administered.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Who TB-500 is discussed for, and the cautions that recur

The interest. Tendon, ligament and muscle injuries, and recovery generally; the audience overlaps almost entirely with BPC-157's.

  • Cancer. Thymosin beta-4 promotes cell migration and blood-vessel growth and is elevated in several tumours; whether supplementing it matters in a person with a tumour is untested and is the caution every review lists first.
  • Athletes. Named on the WADA list, prohibited at all times, detectable.
  • Which molecule is in the vial. Fragment or full protein, at unknown purity; the two are not interchangeable and a certificate of analysis is the only check.
  • Pregnancy, children. No data.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Biomarkers measured in studies

Laboratory and clinical measures the studies report tracking, including which hormones did and did not change.

  • Human study humans 2026 Observational, human
    Among the proteins secreted in significantly higher amounts by resistant cells (compared to the control group), which may be potential biomarkers or therapeutic targets in melanoma, plasminogen activator inhibitor 1, thymosin beta-4, clusterin, interleukin-6, superoxide dismutase, and selected matrix metalloproteinases can be distinguished.
    Source pmid-41742019 · quoted verbatim from the abstract
  • Human study humans n = 43 2025 Observational, human
    Although thymosin beta 4 has shown cardioprotective effects in preclinical MI models, its impact on chronic cardiac functional recovery post ischemia/reperfusion (I/R), especially in STEMI, warrants further investigation.
    Source pmid-41229390 · quoted verbatim from the abstract
  • Human study humans 2024 Observational, human
    In previous studies, it was confirmed that thymosin beta 4 (Tβ4) could enhance fat survival in vivo, although the precise mechanism remains unclear.
    Source pmid-38409346 · quoted verbatim from the abstract
  • Animal study mice 2021 Animal, preclinical
    Tmsb4x (thymosin beta-4 X-linked), Hmox1, Ifitm3, Ldhb, and Itgb7 were identified as strong candidate genes that promote metastasis.
    Source pmid-34081824 · quoted verbatim from the abstract

Reported interactions

Sentences in which the compound is studied alongside another agent. Read the quotation: the word interaction can also be statistical.

  • Animal study rats 2026 Animal, preclinical
    Three independent reviewers searched the PubMed database using permutations of peptide search terms (BPC-157, TB-500, CJC-1295, MK-677 [ibutamoren], ipamorelin, and GHK-Cu) combined with musculoskeletal tissue search terms (bone, fracture, muscle, tendon, ligament, meniscus, and cartilage) following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.
    Source pmid-42578445 · quoted verbatim from the abstract

What is measured over time, and what is not

The full protein is cleared from plasma within hours after infusion. Eye and wound trials measured change over weeks. Nothing has been measured after injecting the fragment in a person; the recovery timelines that circulate are self-report over periods in which injuries heal anyway.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Escalation schedules used in studies

How trials stepped doses, reported as study design.

  • Randomized controlled trial humans n = 72 2007 Human clinical trial
    The objective of this double-blind, placebo-controlled, dose-escalation study is to evaluate safety, tolerability, and enhancement on healing of thymosin beta-4 (Tbeta-4) administered topically in patients with venous ulcers.
    Source pmid-17495250 · quoted verbatim from the abstract

Study durations

Treatment and follow-up periods as stated in each abstract.

  • Randomized controlled trial humans 2021 Human clinical trial
    Durations stated: 10 days; 28 days
    A total of 30 healthy subjects were randomly enrolled in the multiple-dose trial, and 3 cohorts (0.5, 2.0 and 5.0 μg/kg) were administered once human thymosin β4 daily for 10 days and observed for 28 days.
    Source pmid-34346165 · quoted verbatim from the abstract, emphasis added
  • Randomized controlled trial humans n = 5 2016 Human clinical trial
    Durations stated: 6 months
    After 6 months of follow-up, the average 6-min walking distance was increased by 38.2 m (from 263 ± 42 m to 302 ± 34 m) in the control group and 75.7 m (from 264 ± 42 m to 340 ± 44 m) in the experimental group; the average difference of the 6-min walking distance was 37.5 m (95% confidence interval [CI], 28.7-56.3 m; P Discussion Our pilot study suggested that Tβ4-optimized EPC transplantation appeared to be feasible and safe, and might have beneficial effects on exercise capacity and left ventricular function in patients with STEMI.
    Source pmid-27288307 · quoted verbatim from the abstract, emphasis added
  • Randomized controlled trial humans 2015 Human clinical trial
    Durations stated: 56 day; 28 day; 28 days
    A small, multicenter, randomized, double-masked, placebo-controlled 56-day phase 2 clinical trial including a 28-day follow-up at 2 US sites.
    Source pmid-25826322 · quoted verbatim from the abstract
  • Randomized controlled trial humans 2010 Human clinical trial
    Durations stated: 14 days
    Following safety review, subjects were given the same dose regimen daily for 14 days.
    Source pmid-20536472 · quoted verbatim from the abstract, emphasis added
  • Randomized controlled trial humans n = 72 2007 Human clinical trial
    Durations stated: 84 days; 14 days
    So, the study design comprehends 72 patients treated for 84 days and followed for 14 days at the end of treatment.
    Source pmid-17495250 · quoted verbatim from the abstract, emphasis added
  • Human study humans n = 43 2025 Observational, human
    Durations stated: 7 day; 28 days; 1 day
    Methods and results In C57BL/6J mice, 7-day rhTB4 treatment prevented cardiac dysfunction and fibrosis 28 days post-I/R surgery and significantly reduced plasma NT-proBNP levels at both 1 day and 28 days post-I/R.
    Source pmid-41229390 · quoted verbatim from the abstract, emphasis added

Routes used in the studies

Routes of administration named in each study.

  • Randomized controlled trial humans 2021 Human clinical trial
    administration by intravenous route reported
    The study evaluated the safety, tolerability, pharmacokinetics (PK) and anti-drug antibody (ADA) of the recombinant human thymosin β4 (NL005) for single and multiple intravenous injections in healthy subjects.
    Source pmid-34346165 · quoted verbatim from the abstract
  • Randomized controlled trial humans n = 72 2007 Human clinical trial
    administration by topical route reported
    The objective of this double-blind, placebo-controlled, dose-escalation study is to evaluate safety, tolerability, and enhancement on healing of thymosin beta-4 (Tbeta-4) administered topically in patients with venous ulcers.
    Source pmid-17495250 · quoted verbatim from the abstract
  • Animal study mice 2026 Animal, preclinical
    administration by oral route reported
    Conversely, oral administration of recombinant human Tβ4 (rhTβ4) significantly improved survival, alleviated body weight loss, reduced epithelial injury, and suppressed inflammatory cytokine production in both prophylactic and therapeutic colitis models.
    Source pmid-42606759 · quoted verbatim from the abstract

Weight-normalized doses, as published

Per-kilogram figures exactly as each study published them, for the species it studied.

  • Animal study rats 2026 Animal, preclinical
    Weight-normalized doses as published: 60 µg/kg/day
    Thirty-two male Sprague-Dawley rats, each aged 12 weeks and weighing approximately 330 g, underwent standardized Achilles tendon transection and repair and were randomly assigned to four groups, with eight rats in each group: control, BPC-157 (10 µg/kg/day), TB-500 (60 µg/kg/day), and combined BPC-157 + TB-500 (BPC + TB).
    Source pmid-42542926 · quoted verbatim from the abstract, emphasis added

Weight-normalized figures above are reproduced exactly as each study published them, for the species it studied. Dose does not scale linearly with body mass between species: metabolic rate, clearance and receptor density differ, and regulatory guidance uses allometric, not proportional, conversion. A mg/kg figure from a rat study is a fact about that rat study and nothing else.

What people report outside the literature

What circulates in user communities and clinic marketing, reported so a reader knows the figures and their origin. None of it has been tested in a trial, and none of it is a suggestion.

  • TB-500 circulates for injury recovery, tendon and ligament healing, hair and, more speculatively, heart health, injected subcutaneously or intramuscularly on a weekly schedule, and most often paired with BPC-157 as the Wolverine stack. Reported effects are faster recovery and reduced pain; reported side effects are injection-site reactions, transient fatigue, headache and light-headedness. None of this comes from a human study of the fragment. Figures for this compound circulate on forums and vendor pages. None has been tested in a human study, so none is reproduced here; the table above holds every dose a study actually administered.Editorial synthesis
    Editorial synthesis from general knowledge
Method note · shared across compounds

Reconstitution mathematics

Lyophilised peptide is supplied as a mass in a vial and dissolved in a stated volume of diluent. Two figures follow from that and nothing else:

  • Concentration = mass in vial ÷ diluent volume. A 5 mg vial in 2 mL is 2.5 mg/mL, or 2,500 mcg/mL.
  • Volume for a given mass = that mass ÷ concentration. 250 mcg at 2,500 mcg/mL is 0.1 mL. On a U-100 insulin syringe, where 1 mL is 100 units, that is 10 units.

Study doses on this page are quoted as published, in the units the authors used. Converting between mcg, mg and IU, or between a mass and a syringe volume, is arithmetic; deciding a mass is not, and this page does not do it. The reconstitution calculator performs the conversion with the formula shown.

Method note · shared across compounds

Reading a certificate of analysis

A certificate of analysis is a laboratory report on one batch. Reading it means checking four things in order.

  1. Identity. Mass spectrometry should report an observed molecular mass matching the peptide's theoretical mass within the instrument's stated tolerance. A certificate with no mass spectrometry, or one that lists only the expected value, has not confirmed identity.
  2. Purity. HPLC purity is the area of the main peak as a share of all peaks, at a stated wavelength. It says nothing about what the other peaks are, and it is not a measure of quantity.
  3. Quantity. Net peptide content, by amino acid analysis or UV, is the fraction of the vial's mass that is peptide rather than counter-ions and water. A 5 mg vial at 80% net content holds 4 mg of peptide, and every concentration figure above changes accordingly.
  4. Provenance. The batch number on the certificate should match the vial, the laboratory should be named and independent of the seller, and the test date should be recent.

This page rates no supplier and links to none. It describes how to read the document.

Method note · shared across compounds

Equipment described in studies

Published human studies of injectable peptides report the same small set of materials: single-use insulin syringes with fixed needles, most often U-100 with 29 to 31 gauge needles; bacteriostatic water or sterile water for injection as diluent, with the choice stated in the methods; alcohol swabs; and refrigerated storage of reconstituted solution. Animal studies more often report intraperitoneal or intragastric administration and state the vehicle used. Where a study in this record's ledger names its materials or vehicle, that sentence appears under storage or routes above; where it does not, nothing is assumed here.

Storage and handling

Powder refrigerated or frozen away from light; reconstituted solution refrigerated and used within about four weeks. Discard cloudy or discoloured solution. The full protein and the fragment have different molecular weights, so the same labelled mass is a different number of molecules.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Common mistakes in how TB-500 is discussed

  • Quoting thymosin beta-4 trials as TB-500 evidence. Eye drops and wound gels of the full protein say nothing about an injected fragment.
  • Counting 1,257 publications as support. Most are cell biology of a ubiquitous protein.
  • Reading the 2010 phase 1 study as safety data for what is sold. It was the full protein, intravenous, in healthy people, for two weeks.
  • Assuming the Wolverine stack was studied in people. One rat study.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

TB-500 vs BPC-157, GHK-Cu and KPV

CompoundMechanism (proposed)Human evidenceStatus
TB-500 / thymosin β4Actin binding; cell migration; angiogenesisTrials of the full protein in eyes and wounds; none of the fragmentNot approved; WADA S2
BPC-157Gastric-protein fragment; nitric oxide, growth factors3 uncontrolled pilotsNot approved; FDA Category 2; WADA S0
GHK-CuCopper tripeptide; collagen, gene expressionTopical trialsCosmetic ingredient
KPVα-MSH fragment; anti-inflammatoryNoneNot approved

Pages: BPC-157 vs TB-500, the Wolverine stack, and the records for BPC-157, GHK-Cu and KPV.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Other compounds in its class

Same class in the registry: BPC-157, GHK-Cu, KPV. Each row shows what that compound's own record states; nothing is inferred across rows. Head-to-head evidence, where any exists, is on the comparison page: BPC-157 vs TB-500.

4 compounds in the repair & anti inflammatory class. Each row states what that compound's own record says; nothing is inferred across rows.
CompoundTierPublicationsRCTsRecord
TB-500 Human clinical trial 1,257 7 draft
BPC-157 Observational, human 228 0 draft
GHK-Cu Human clinical trial 169 1 draft
KPV Animal, preclinical 138 0 draft

Studied in combination

Whether any indexed study tested TB-500 together with the compounds it is commonly combined with. A count of zero is the finding, not a gap in this page.

Regulatory status

Registry facts only. Jurisdiction-level status, compounding categories and sport prohibitions need their own cited documents before they appear here.

  • Not approved anywhere: neither the fragment nor the full protein has a marketing authorisation. Thymosin beta-4 products reached phase 2 and 3 trials in eye and wound conditions without approval. TB-500 is named on the WADA Prohibited List under S2 (peptide hormones, growth factors, related substances and mimetics), prohibited at all times. TB-500 was among the peptides scheduled for FDA's Pharmacy Compounding Advisory Committee in July 2026; secondary reports say the committee recommended adding it to the compounding list; that is unverified here until FDA's own record is in the ledger, and it does not make TB-500 prescribable yet.Editorial synthesis
    Editorial synthesis from general knowledge · primary document to be added to the ledger

Open questions and limitations

What is genuinely unknown, stated plainly. A missing field is not evidence that the outcome is safe, effective, or established.

  • No study in this record's ledger reports exclusion criteria for TB-500.
  • No study in this record's ledger reports adverse events or their frequency for TB-500.
  • No study in this record's ledger reports onset or duration of effects for TB-500.
  • No study in this record's ledger reports storage or stability for TB-500.

Questions people ask

What are the side effects of TB-500?

The intravenous phase 1 study of the full protein found no dose-limiting toxicity over two weeks. Community reports of the fragment describe injection-site reactions, fatigue and headache. Long-term effects are unknown.

Does TB-500 help hair growth?

Thymosin beta-4 promotes hair follicle cell migration in mice. No human study of TB-500 or the protein for hair exists.

What is TB-500?

Usually a seven-amino-acid fragment of thymosin beta-4, a protein present in nearly every cell that regulates actin and cell movement. Some products sold as TB-500 are the full 43-amino-acid protein.

Is TB-500 the same as thymosin beta-4?

Not usually. TB-500 is typically the actin-binding fragment; thymosin beta-4 is the full protein, which is what the human trials tested.

Has TB-500 been tested in humans?

The fragment has not. The full protein has phase 1 to 3 trials as eye drops, topical gel and intravenous infusion.

What does TB-500 do?

In animals and cells the full protein promotes cell migration into wounds, new blood vessels, and reduced scarring, and protects heart muscle in injury models. The fragment's injected effects rest on one rat tendon study.

Is there a TB-500 dose?

No human dose has been studied for the fragment. Trial doses of the full protein are listed above by route; figures that circulate for injection are untested and not reproduced here.

What are the side effects of TB-500?

The intravenous phase 1 study of the full protein found no dose-limiting toxicity over two weeks. Community reports of the fragment describe injection-site reactions, fatigue and headache. Long-term effects are unknown.

Is TB-500 FDA approved?

No, and neither is thymosin beta-4. TB-500 was considered by FDA's compounding advisory committee in July 2026; secondary reports say the committee recommended adding it to the compounding list. FDA's own record is not yet in this ledger, and a recommendation does not make it prescribable.

Is TB-500 banned in sport?

Yes. Named on the WADA Prohibited List under S2, prohibited at all times.

Can BPC-157 and TB-500 be used together?

Communities do, as the Wolverine stack. One 2026 rat tendon study tested the pair; no human study has.

Does TB-500 help hair growth?

Thymosin beta-4 promotes hair follicle cell migration in mice. No human study of TB-500 or the protein for hair exists.

Is TB-500 good for the heart?

The full protein protects heart muscle in animal injury models and one small uncontrolled human study reported improved walking distance. No controlled human evidence.

What is TB-500's half-life?

The full protein is cleared from plasma within hours after infusion. The fragment's half-life in people has not been measured.

How should TB-500 be stored?

Powder refrigerated or frozen away from light; reconstituted solution refrigerated and used within about four weeks.

TB-500 vs BPC-157: which is better?

Neither has controlled human evidence for healing; they act by different proposed mechanisms; one rat study tested both without ranking them.

How many TB-500 studies exist?

1,257 indexed publications for thymosin beta-4 and its aliases, mostly basic cell biology; 25 primary studies are tabulated here, 14 of them in humans and all of those on the full protein.

Who developed thymosin beta-4 as a drug?

RegeneRx, as RGN-259 eye drops, RGN-137 gel and RGN-352 intravenous, through phase 2 and 3 trials without approval.

Sources

Full citations. Every claim above links to one of these by its id.

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    Engineered Tandem Thymosin Peptide Promotes Corneal Wound Healing.
    pmid-41235866 · · peer-reviewed
  5. 17
  6. 18
    The Prognostic Significance of TMSB4X in Glioma Patients.
    pmid-40502330 · · peer-reviewed
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    The effect of thymosin treatment of venous ulcers.
    pmid-20536470 · · peer-reviewed
  33. 45
    Collateral circulation: past and present.
    pmid-19101749 · · peer-reviewed
  34. 46
  35. 47
  36. 48
  37. 49
    Actin binding proteins: regulation of cytoskeletal microfilaments.
    pmid-12663865 · · peer-reviewed
  38. 50
    beta-Thymosins, small acidic peptides with multiple functions.
    pmid-11311852 · · peer-reviewed
  39. 51

Reference card

Reference card · generated /compounds/tb-500
Compound
TB-500, repair and anti inflammatory
Evidence tier
Human clinical trial
Indexed publications
1,257 · 7 RCTs · 6 other clinical trials
Approval
no registered development programme found
Routes reported
intravenous, oral, topical
Reviewed
Adam Mirando, PharmD,

Study figures are as published in each source and are not recommendations. Print or save this card with its date.

Last reviewed and what changed

Newest first. These are the record's own revision dates, and the same dates feed the sitemap.

  1. · Reviewed by Adam Mirando, PharmD, on 2026-09-25.
  2. · Misattribution check: evidence_table (pmid-42578445): a review's collective sentence about six peptides is not one compound's evidence row. The sources stay in the ledger; only the claims that put another agent's result under this compound were removed.
  3. · Regulatory note updated: secondary reports of the July 2026 PCAC recommendation recorded as unverified pending FDA's record. Stage 2 competitors and information gain written to the intent map.
  4. · Written guide, FAQ to 16, mechanism, reported-use (no circulating figures reproduced) and regulatory editorial sections; fragment-versus-full-protein distinction made explicit throughout; intent-driven H1 and title.
  5. · Claims drafted extractively from 50 ledger sources by scripts/draft_claims.py: 17 claims, 25 evidence-table rows. Status researched -> draft.
  6. · Claims drafted extractively from 50 ledger sources by scripts/draft_claims.py: 36 claims, 25 evidence-table rows. Status researched -> draft.
  7. · Evidence fetched from Europe PMC and ChEMBL by scripts/fetch_evidence.py; claims not yet written.