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TB-500: what the studies show, status and safety

Status at a glance

MarketStatusDate
United StatesNot approved—
European UnionNot approved—
GermanyNot approved—
United KingdomNot approved—
AustraliaScheduled substance2024-06-01
CanadaNot approved—
SwitzerlandNot established—
Development stage
Preclinical
Strongest evidence
Animal study
WADA status
Prohibited (S2.3, 2026)
Last verified
2026-09-30
Version
1.1

TB-500: what the studies show, status and safety

Summary

This page uses TB-500 for Ac-LKKTETQ, the synthetic, N-acetylated seven-amino-acid fragment of thymosin β4. TB-4 is the full-length, 43-amino-acid peptide; unacetylated LKKTETQ is a third substance. Products and publications use the name TB-500 inconsistently. Human trials of TB-4 do not establish the efficacy, safety or dose of this fragment. The FDA identified no clinical studies of the fragment in its 2026 evaluation.

Key findings at a glance

  • Clinical evidence is missing. The FDA’s 2026 review found no assessable clinical studies of Ac-LKKTETQ [35].
  • The molecule matters. Human trials of full-length TB-4 are not trials of Ac-LKKTETQ. Findings for the unacetylated fragment also need separate attribution [10], [35].
  • Both large late-stage trials of the parent protein failed. One of them enrolled 601 people and the other 700, and neither showed a difference on either of its two main questions [3], [4].
  • Uncertain material in the tendon study. The rat study does not establish whether the product labelled TB-500 contained Ac-LKKTETQ or full-length TB-4 [5].
  • In the dish, a breakdown product closed wounds, not TB-500 itself. In a 2024 study, only one of the fragments the body cuts the peptide into showed a clear effect [6].
  • Most of the samples tested contained no peptide at all. A university racing laboratory reported that most products labelled TB-500 held no proteins, no peptides and no amino acids [7].
  • Banned in sport around the clock. Section S2.3 of the 2026 list names "Thymosin-β4 and its derivatives e.g. TB-500", and files it in the stricter of the two categories [8].

What it is

Here, TB-500 means Ac-LKKTETQ, following its analytical identification and the FDA’s 2026 definition [10], [35]. The trade name alone does not establish a product’s identity. TB-4 (thymosin β4) has 43 amino acids; unacetylated LKKTETQ / fequesetide has seven, but a different chemical structure. The dedicated TB-500 vs. TB-4 comparison separates their evidence.

In 2012, the doping control laboratory in Ghent identified Ac-LKKTETQ in a product sold as TB-500. The researchers used high-resolution mass spectrometry and synthesized the same peptide to confirm its identity. This established the contents of the tested product, not every product sold under that name [10].

The authorities treat the fragment and the complete protein as two different substances. Australia lists them separately in its poisons schedule [11], and the FDA lists the fragment apart from the programmes for the whole protein [1].

Quick facts

FieldValueRef
Common namesTB-500, TB500, Ac-LKKTETQ[9]
Name used by the authoritiesThymosin beta-4, fragment (LKKTETQ)[1]
ClassLab-made peptide of seven building blocks, a piece of a human protein[9], [10]
SequenceAc-Leu-Lys-Lys-Thr-Glu-Thr-Gln[9]
Formula and massC38H68N10O14, 889.0 g/mol[9]
The protein it comes fromThymosin β4, 43 building blocks, about 4.9 kilodaltons[12]
How long it lasts in peopleNever published[6]
StatusNo approval in the markets reviewed by FDA[1], [11]
Who developed itNo verified clinical development programme[1]
CAS registry number885340-08-9[9]
UNIIQHK6Z47GTG[9]
PubChem CID62707662[9]

TB-500: what the studies show, status and safety

How it works

Nothing about how it works has ever been measured in a person, so every point below is a hypothesis carried over from cells and animals [1].

  • Gripping the cell scaffold. The stretch LKKTET is the part of thymosin β4 that grips actin, the building material of the cell scaffold, so a peptide carrying it may grip actin too and affect how cells crawl [12]. How firmly it grips depends heavily on what surrounds the stretch, so the piece on its own need not behave like the whole protein [13].
  • New blood vessels and repair. Within the complete protein, this region has been linked to the growth of new blood vessels, to wound healing and to cell movement [12].
  • A stand-in for the whole protein. In old mice, the uncapped version of the peptide healed skin about as well as the complete protein did [14]. That single comparison from 2003 carries much of the reasoning that came afterwards.
  • Possibly a breakdown product does the work. A 2024 study of how the body cuts the peptide up suggests that the wound-healing effect may belong to one of those fragments rather than to the peptide that was given [6].
  • Not the part that calms inflammation. The calming effect of thymosin β4 on inflammation is attributed to a completely different piece of the protein, one that TB-500 does not contain [12], [7].
  • Not the route described for the heart. The chain of proteins that was said to protect the heart in mice was described for the complete protein, not for this fragment [15].

That split matters. Much of what is claimed for TB-500 is attributed in the original literature to parts of thymosin β4 that this fragment leaves out entirely.

What the trials found

Research on TB-500 consists mainly of chemical analyses and animal or cell experiments. The FDA’s 2026 review found no assessable clinical studies of the defined fragment Ac-LKKTETQ [35].

Tendon

Animal data; chemical identity unresolved Biçer and colleagues studied 32 rats in four groups, with only four tendons per group allocated to each endpoint. The material called TB-500 was associated with higher load to failure (p < 0.05) and lower Bonar and Movin scores (p = 0.016 and p = 0.017); the combination added no benefit [5]. However, the methods give a catalogue reference without a sequence, CAS number or analytical identity check. This study therefore cannot be assigned confidently to Ac-LKKTETQ or to full-length TB-4.

Skin wounds

Animal data In mice aged 26 months, the uncapped peptide of seven building blocks healed skin about as well as the complete protein did [14]. That peptide is not the same molecule as the capped fragment sold as TB-500. For the complete protein in rats, the new skin covering the wound grew 42 percent further along by day 4 and up to 61 percent further by day 7 than with salt water, and the wounds had pulled themselves at least 11 percent tighter by day 7 [16].

Which molecule is active

In vitro A 2024 study followed TB-500 and the fragments it breaks into, in human blood serum, in enzyme mixtures and in rats. One short fragment dominated the first six hours, and another could still be found after 72 hours. In the wound-healing test, only one particular fragment produced a clear effect, and the peptide that had been given produced none [6].

Cornea and brain

Other molecules and preparations The corneal hydrogel study uses the name TB500 for a modified peptide preparation [17]. The brain study examines thymosin β4-derived peptides [18]. Neither establishes that ordinary Ac-LKKTETQ has the reported effects. The preparation and chemical identity must be checked before either result is attributed to TB-500.

The parent protein in people

Full-length TB-4, phase 1 A placebo-controlled study enrolled 40 healthy volunteers and reported no dose-limiting toxicity [19]. This was a different molecule; its findings and human doses do not establish safety or dosing for Ac-LKKTETQ. Details are in the TB-4 monograph.

Phase 2 Two trials with 72 patients each tested a gel applied to the skin, and both were designed above all to check safety. By day 84, pressure sores had closed in 8 of 54 patients receiving active treatment and 3 of 18 receiving placebo. In the leg-ulcer trial, the corresponding figures were 12 of 55 and 4 of 17. The pooled treatment groups were larger, so the raw counts do not show a benefit [20].

A review written by the developers reports healing almost a month sooner, but only among those wounds that closed at all [21]. Neither line of work went on to a late-stage trial.

Phase 3 One late-stage trial tested 0.1% eye drops in a condition where the cornea loses its nerve supply and stops healing. After four weeks the surface had healed completely in 6 of 10 treated eyes against 1 of 8 on dummy drops, a difference that just missed the usual threshold for being more than chance (p = 0.0656). The trial stopped after 18 participants [22].

Endpoints that were missed

One large trial assigned 601 people with dry eyes by chance to treatment or dummy drops, and it failed on both of its two main questions [3]. Its successor did the same with 700 people and also failed on both, with the damage to the lower cornea improving by 0.41 points against 0.46 points on the dummy drops [4].

ARISE-2 co-primary endpoints at day 29
Eye discomfort, drops
0.07 points
Eye discomfort, placebo
−0.04 points
Corneal staining, drops
0.07 points
Corneal staining, placebo
−0.01 points

Neither primary endpoint was met. Late-stage trial with 601 participants, using drops of the complete protein and not the TB-500 fragment. Source [3].

An independent Cochrane review looked at SEER-1 and calculated that healing was nine times as likely under treatment (relative risk 9.00), but the range around that figure runs from far below to far above it (0.57 to 141.88), so the evidence counts as weak [23]. A European late-stage trial also failed on its main question according to the trade press [24]. The registry entry for a further trial, retrieved on 6 September 2026, listed it as recruiting. That entry does not confirm that recruitment was still taking place [25].

What is still unknown

  • Human efficacy and safety. Assessable clinical studies of Ac-LKKTETQ are missing [35].
  • Whether the evidence for the whole protein carries over. Several of the things thymosin β4 does are attributed to parts of it that the fragment does not copy [12], [15].
  • Which molecule would actually do the work. The finding about the breakdown products leaves it open which substance is the active one [6].
  • Questions about cancer and blood vessels. Something that encourages new vessels and makes cells move raises obvious questions about undetected tumours, and no study has looked at them [12], [26].
  • What happens over the long run. For the fragment, no cancer study and no standard set of tests for damage to genetic material has ever been published.

Side effects and safety

Without assessable clinical data, the frequency and severity of TB-500 adverse effects cannot be established. Missing data are not evidence of safety [35].

The FDA’s 2026 review also mentions two reports about products labelled as TB-500/BPC-157 blends in its food complaint system, but neither contained a safety assessment. These reports do not identify the responsible molecule or establish safety, efficacy or an adverse-event rate [35].

  • Immune reactions and impurities. The FDA names both as risks for pharmacy-made preparations of the fragment, pointing to possible clumping and to impurities that come with the peptide itself [1].
  • No damage to skin cells in one test. Neither the peptide nor its breakdown products killed cells in a single laboratory test [6]. One cell line is not a safety assessment.
  • Full-length TB-4, phase 1 · A placebo-controlled study enrolled 40 healthy volunteers and reported no dose-limiting toxicity [19]. This was a different molecule; its findings and human doses do not establish safety or dosing for Ac-LKKTETQ. Details are in the TB-4 monograph.
  • A product name does not verify its contents. A university racing laboratory reported that many samples sold under this name contained neither thymosin β4 nor any peptide derived from it. Most held no proteins, peptides or amino acids at all, and only a single sample actually contained the capped fragment [7].
  • A second laboratory found the same. In 2023, a French racing laboratory examined products sold as TB500 and TB1000 as wrongly labelled and adulterated medicines, and found that the contents did not reliably match the descriptions [27].
  • Reviews emphasise the evidence gaps. A 2026 sports medicine review notes encouraging animal results but scarcely any safety data from people, and the possibility of serious harm [26]. A systematic overview found that 67 percent of the publications are laboratory work, and advises against using the peptide alongside standard orthopaedic care [28].

Major safety questions remain unanswered. Nothing is known about injecting it repeatedly, about pregnancy, about children, or about people whose liver or kidneys work poorly, because nobody has looked [1].

Doses used in studies

These are reported research conditions, not advice for human use. Only studies identifying Ac-LKKTETQ are listed. Human doses of full-length TB-4 and experiments with unacetylated LKKTETQ do not establish doses of TB-500.

StudySubstanceModelDoseRouteDurationRef
Ho 2012, detection methodThe fragmentHorseOne dose of a preparation containing 10 mgNot statedOnce[29]
Rahaman 2024, breakdownThe fragmentRat, and in the dishNot given in numbers in the abstractNot statedSamples taken up to 72 h[6]

The clinical programmes for full-length thymosin β4 concern a different molecule. Their results and doses cannot be assigned to Ac-LKKTETQ, and findings for unacetylated LKKTETQ cannot be directly assigned to the acetylated fragment either [19], [35].

Development and approval status

How the field developed

  1. 1999The complete protein speeds up wound healing in ratsNew skin covered 42% more of the wound by day 4, ref [16]
  2. 2003LKKTETQ (847 g/mol)Mouse skin study of unacetylated fragment and full-length TB-4; not evidence for Ac-LKKTETQ. [14], [35]
  3. 2004Paper in Nature on heart repair by the complete proteinA chain of signalling proteins in mice, ref [15]
  4. 2010Different effects traced to different parts of the proteinOne piece calms inflammation, another drives new vessels, ref [12]
  5. 2012Doping laboratories identify Ac-LKKTETQ in a marketed productGhent and Hong Kong, refs [10], [29]
  6. 2013Racing bulletin reports that most labelled samples hold no peptideThe strictest penalty class recommended, ref [7]
  7. 2016Sports court bans 34 Australian footballers over thymosin beta-4Not one positive test was involved, ref [30]
  8. 2018-2021Two large eye trials miss both primary endpoints601 and 700 participants, refs [3], [4]
  9. 2022A small trial reports 6 of 10 healed against 1 of 8Stopped after 18 participants, and the result just missed significance, p = 0.0656, ref [22]
  10. 2024Australia lists TB-500 separately from thymosin β4Prescription-only, plus the appendix that bans possession, ref [11]
  11. 2025-2026The anti-doping lists name TB-500, and Cochrane rates the evidence weakRefs [8], [23]
  • 1999 to 2004 — the complete protein produces results in animals, for wounds and for the heart [16], [15].
  • 2003 — Unacetylated LKKTETQ (847 g/mol) is compared with full-length TB-4 in mice. The results do not establish effects of Ac-LKKTETQ [14], [35].
  • 2012 — doping laboratories identify Ac-LKKTETQ in a product marketed as TB-500 [10], [29].
  • 2013 — the racing bulletin documents wrongly labelled product and advises the strictest penalty class [7].
  • 2018 to 2022 — the three eye trials of the complete protein come back negative or inconclusive [3], [4], [22].
  • 2024 — Australia lists TB-500 by name, separately from thymosin β4 [11].
MarketStatusNoteRef
United StatesNot approvedFDA evaluation of the fragment[1], [35]
European UnionNot approvedNo centrally authorised products according to FDA[35]
GermanyNot approvedExplicitly included in the FDA review[35]
United KingdomNot approvedNo approved products according to FDA[35]
AustraliaRestrictedSchedule 4 and Appendix D; not product approval[11], [35]
CanadaNot approvedNo approved products according to FDA[35]
SwitzerlandNot independently verifiedNot covered by the FDA country review—

The earlier review of 6 September 2026 used the FDA page dated 22 April 2026 for the US entry [1]. The additional FDA evaluation supports the entries for the other named markets; it does not cover Switzerland [35]. Australia's Poisons Standard, effective 1 June 2026, retains the entry from June 2024. Clause 5 of Appendix D also regulates possession without appropriate authority [11].

Anti-doping

TB-500 is banned at all times, both in and out of competition. Section S2.3 of the 2026 Prohibited List names "Thymosin-β4 and its derivatives e.g. TB-500", and the heading of that section states that everything in it counts as non-specified, the stricter of the two categories [8]. That is harsher than the treatment of BPC-157, which sits in another section as a specified substance. The American college sports association names TB-500 as well [31].

Detecting it is not the obstacle it is often made out to be. Methods have existed since 2012, and the peptide is part of the routine screening laboratories run for small peptides, including in dried drops of blood [10], [32].

In horses, the reported detection limits are 0.02 ng/mL in blood plasma and 0.01 ng/mL in urine [29]. The racing body advises testing outside competition, because the peptide can only be found for a short while [7]. The wider picture is at peptides banned in sport.

One case shows that a positive sample is not even needed. In January 2016 the Court of Arbitration for Sport banned 34 Australian footballers over a supplement programme built around thymosin beta-4. Not one of them had ever tested positive [30].

Compared with related peptides

Here, TB-500 means Ac-LKKTETQ, following its analytical identification and the FDA’s 2026 definition [10], [35]. The trade name alone does not establish a product’s identity. TB-4 (thymosin β4) has 43 amino acids; unacetylated LKKTETQ / fequesetide has seven, but a different chemical structure. The dedicated TB-500 vs. TB-4 comparison separates their evidence.

PeptideWhat it isHuman evidenceStatus in sportStrongest result in its own study
TB-500Lab-made fragment of 7 building blocksNo assessable clinical studiesBanned, S2.3, stricter category [8]Analytical and metabolism studies; no significant parent-peptide effect in one scratch assay [6], [10]
Thymosin β4Human protein of 43 building blocksClinical trials through phase 3; trial findings are separate from approvalBanned, S2.3, named [8]6 of 10 eyes healed against 1 of 8, in only 18 participants [22]
BPC-157Lab-made sequence of 15 building blocksA few small and weak observations in peopleBanned, S0, milder category [8]No clear change in the overall score in the same rat study [5]
GHK-CuA short peptide bound to copperUsed in cosmetics, no approved medicineNot named on the 2026 list [33]Assessed as a cosmetic ingredient, not as a trial result [34]

The clinical programmes for full-length thymosin β4 concern a different molecule. Their results and doses cannot be assigned to Ac-LKKTETQ, and findings for unacetylated LKKTETQ cannot be directly assigned to the acetylated fragment either [3], [4], [35].

The single study that tested TB-500 and BPC-157 against each other and in combination found no advantage in combining them [5]. GHK-Cu sits in an entirely different regulatory world, as a cosmetic ingredient rather than a drug under investigation [34].

Common misconceptions

  • “TB-500 and TB-4 are the same.” Ac-LKKTETQ has seven amino acids and a mass of about 889 g/mol, whereas TB-4 has 43 amino acids and a mass of about 4.9 kDa. However, TB-500 is used inconsistently as a trade name, including for full-length TB-4; the label alone does not identify the molecule [10], [35].
  • “TB-4 trials also prove the fragment works.” The clinical programmes for full-length thymosin β4 concern a different molecule. Their results and doses cannot be assigned to Ac-LKKTETQ, and findings for unacetylated LKKTETQ cannot be directly assigned to the acetylated fragment either [12], [35].
  • “A registry entry proves a trial is running.” No verified ongoing clinical trial of Ac-LKKTETQ was identified in the checked sources. A registry listing alone does not demonstrate that a study is real or that it provides clinical results [2], [35].
  • “FDA committee review means approval.” The FDA’s 2026 evaluation found no approved TB-500 medicine in the USA or the other markets it checked, including the EU, UK, Australia and Canada. A compounding discussion is not a marketing authorisation. No FDA-approved equine use was identified [1], [35].
  • "What the label says is what is in the vial." Two specialist laboratories on two continents report the opposite, with most samples containing no peptide whatsoever [7], [27].
  • "It is legal because it is sold for horses." It is not approved for horses either, and the racing body treats giving it to a horse at all as a prohibited act [7].

Frequently asked questions

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

Chemically, no: Ac-LKKTETQ has seven amino acids and a mass of about 889 g/mol, whereas TB-4 has 43 amino acids and a mass of about 4.9 kDa. However, TB-500 is used inconsistently as a trade name, including for full-length TB-4; the label alone does not identify the molecule.

Has TB-500 ever been tested in people?

No verified clinical study of Ac-LKKTETQ was identified. The FDA’s 2026 review found no assessable clinical safety or efficacy data. That is a finding about the evidence, not proof that no person has ever used a product labelled TB-500.

Is TB-500 approved anywhere?

The FDA’s 2026 evaluation found no approved TB-500 medicine in the USA or the other markets it checked, including the EU, UK, Australia and Canada. A compounding discussion is not a marketing authorisation. No FDA-approved equine use was identified.

Is TB-500 banned in sport?

Yes, at all times, both in and out of competition. Section S2.3 of the 2026 Prohibited List names thymosin-beta-4 and everything derived from it, and gives TB-500 as the example. Every substance in that section counts as non-specified, which is the stricter of the two categories.

Can TB-500 be detected in a doping test?

Yes. Methods for finding it have existed since 2012, and the peptide is part of the routine screening that laboratories run for small peptides, including in dried drops of blood. In horses, the reported detection limits are 0.02 ng/mL in blood plasma and 0.01 ng/mL in urine.

Do the thymosin beta-4 trials apply to TB-500?

No. The clinical programmes for full-length thymosin β4 concern a different molecule. Their results and doses cannot be assigned to Ac-LKKTETQ, and findings for unacetylated LKKTETQ cannot be directly assigned to the acetylated fragment either.

Is there a clinical trial of TB-500 running?

No verified ongoing clinical trial of Ac-LKKTETQ was identified in the checked sources. A registry listing alone does not demonstrate that a study is real or that it provides clinical results.

What is in products sold as TB-500?

Often not what the label says. A university laboratory reported that many samples sold under this name contained neither thymosin beta-4 nor any peptide derived from it, and that most contained no proteins, peptides or amino acids whatsoever. A French racing laboratory came to the same conclusion in 2023.

Does combining TB-500 with BPC-157 work better?

No reliable human evidence establishes an added benefit for Ac-LKKTETQ combined with BPC-157. A 2026 rat study found no added benefit, but did not report a sequence or analytical confirmation of the material it called TB-500.

Sources

  1. US Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks; entry "Thymosin beta-4, fragment (LKKTETQ), also known as TB-500", listed under bulk drug substances nominated but withdrawn. Content current as of 22 April 2026, retrieved 6 September 2026. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
  2. ClinicalTrials.gov. NCT07487363, sponsor Hudson Biotech. Its summary explicitly describes a fictional example; excluded as clinical evidence. Record checked 30 September 2026. https://clinicaltrials.gov/study/NCT07487363
  3. ClinicalTrials.gov. NCT02974907, ARISE-2, RGN-259 in dry eye disease, phase 3, n = 601; results section, both co-primary endpoints. Retrieved 6 September 2026. https://clinicaltrials.gov/study/NCT02974907
  4. ClinicalTrials.gov. NCT03937882, ARISE-3, RGN-259 in dry eye disease, phase 3, n = 700; results section, both co-primary endpoints. Retrieved 6 September 2026. https://clinicaltrials.gov/study/NCT03937882
  5. Biçer O, Adanir O, Güleryüz Y, Balci EC, Dinçel YM, Yenigün MY, Aydin C, Bayrak BY (2026). Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: a histopathological and biomechanical study. Joint Diseases and Related Surgery 37(3):822-837. PMID 42542926. DOI 10.52312/jdrs.2026.2951
  6. Rahaman KA, Muresan AR, Min H, Son J, Han HS, Kang MJ, Kwon OS (2024). Simultaneous quantification of TB-500 and its metabolites in in-vitro experiments and rats by UHPLC-Q-Exactive orbitrap MS/MS and their screening by wound healing activities in-vitro. Journal of Chromatography B 1235:124033. PMID 38382158. DOI 10.1016/j.jchromb.2024.124033
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  23. Kruoch Z, Choo AY, Kemp A, Gonzales M, Yim TW, McCann P, Liu SH, Ting DSJ, Kuo IC (2025). Medical and surgical interventions for neurotrophic keratopathy. Cochrane Database of Systematic Reviews 12(12):CD015723. PMID 41347649. DOI 10.1002/14651858.CD015723.pub2
  24. Ophthalmology Times. HLB Therapeutics misses primary end point in phase 3 SEER-3 trial of RGN-259. Secondary source; full text not retrievable on 6 September 2026 (HTTP 403).
  25. ClinicalTrials.gov. NCT05555589, SEER-2, 0.1% RGN-259 in neurotrophic keratopathy, phase 3, n = 70; recruiting since 11 April 2023. Retrieved 6 September 2026. https://clinicaltrials.gov/study/NCT05555589
  26. Mendias CL, Awan TM (2026). Safety and efficacy of approved and unapproved peptide therapies for musculoskeletal injuries and athletic performance. Sports Medicine 56(8):1921-1935. PMID 41966639. DOI 10.1007/s40279-026-02437-0
  27. Delcourt V, Garcia P, Chabot B, Barnabé A, Bouscarel M, Loup B, Popot MA, Bailly-Chouriberry L (2023). TB500/TB1000 and SGF1000: a scientific approach for a better understanding of misbranded and adulterated drugs. Drug Testing and Analysis 15(4):458-464. PMID 36482504. DOI 10.1002/dta.3421
  28. Tewari K, Liu TP, Im C, Hamad C, Petrigliano F, Cheung EC, Kremen TJ Jr (2026). Peptide supplements and their therapeutic applications in sports medicine. American Journal of Sports Medicine. PMID 42578445. DOI 10.1177/03635465261464420
  29. Ho EN, Kwok WH, Lau MY, Wong AS, Wan TS, Lam KK, Schiff PJ, Stewart BD (2012). 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. Journal of Chromatography A 1265:57-69. PMID 23084823. DOI 10.1016/j.chroma.2012.09.043
  30. Court of Arbitration for Sport decision of 12 January 2016 in the Essendon Football Club matter, banning 34 current and former players over a thymosin beta-4 supplement programme; no player had returned a positive sample. Secondary sources: ABC News, AFL.com.au, Sports Integrity Initiative. https://www.abc.net.au/news/2016-01-12/cas-upholds-wada-appeal-essendon-anti-doping-verdict/7081874
  31. National Collegiate Athletic Association. 2026-27 NCAA banned substances, class 6, peptide hormones, growth factors, related substances and mimetics. Full text extracted 6 September 2026. https://ncaaorg.s3.amazonaws.com/ssi/substance/2026-27/2026-27NCAA_BannedSubstances.pdf
  32. Multi-analyte screening methods including TB-500: Drug Testing and Analysis 2016 (PMID 26472487); Journal of Chromatography A 2022 (PMID 35802965); Analyst 2026, dried and liquid blood matrices (PMID 42328738)
  33. PubChem. Compound CID 139035031, GHK-Cu (copper tripeptide), C14H21CuN6O4, 400.9 g/mol, retrieved 6 September 2026; full-text search of the 2026 Prohibited List returned no entry for GHK or glycyl-histidyl-lysine on 6 September 2026. https://pubchem.ncbi.nlm.nih.gov/compound/139035031
  34. Pickart L, Margolina A (2018). Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. International Journal of Molecular Sciences 19(7):1987. PMID 29986520. DOI 10.3390/ijms19071987
  35. US Food and Drug Administration (2026). Evaluation of TB-500-related Bulk Drug Substances, briefing dated 15 May 2026 for the July 2026 Pharmacy Compounding Advisory Committee meeting. Chemical identity pp. 7–10; nonclinical evidence pp. 24–28; human data and two unevaluated blend reports pp. 29–30. Checked 30 September 2026. https://www.fda.gov/media/193349/download

Cite this page

Chemical identity and the attribution of study findings were reviewed again on 30 September 2026. The status table identifies its sources; Swiss authorisation status remains unverified.

myPeptides Research & Editing. (2026). TB-500: what the studies show, status and safety. Version 1.1, 30 September 2026. myPeptides Peptide Register. Retrieved from https://mypep.app/peptides/tb-500

How pages in this register are compiled and graded is described under methodology; the full register is at peptides.

VersionDateChange
1.02026-09-06Initial publication
1.12026-09-30Identity and evidence audit: separate TB-4, qualify trade names and tendon material, remove unrelated dose rows.

Last verified: 30 September 2026. Next review: on publication of any human study of the fragment, on a change in the anti-doping classification, or on a change in the FDA or Poisons Standard entries.

Identifiers

IdentifierValue
CAS number885340-08-9
PubChem CID62707662
UNIIQHK6Z47GTG
InChIKeyADKDNDYYIZUVCZ-ZQNQAVPYSA-N
WikidataQ137400007
Molecular formulaC38H68N10O14
Molecular weight889
SequenceAc-LKKTETQ

Related peptides

Comparisons

Cite this page

Use this reference when you quote the page, and the JSON export when you process it automatically.

myPeptides Research & Editing (2026). TB-500: what the studies show, status and safety (Version 1.1). myPeptides. https://mypep.app/peptides/tb-500

Machine-readable version (JSON)

Last reviewed: September 2026

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