TB-500
TB-500 (synthetic thymosin beta-4 fragment)
What is TB-500?
TB-500: Synthetic peptide based on the active actin-binding region of thymosin beta-4 (Tβ4), a natural 43-aa protein that regulates actin, cell migration and angiogenesis. The sources cited here most often discuss it for: Wound healing, mostly preclinical; Cardiac repair, preclinical; Injury recovery, anecdotal. Evidence label: Preclinical.
- Type
- Peptide
- Family
- Repair & Recovery
- Evidence label
- Preclinical (2 of 5)
- Regulatory status
- Not FDA-approved; in July 2026 an FDA advisory panel voted 8-6 to recommend letting pharmacies compound TB-500, reviewed for wound healing, a nonbinding recommendation that still requires formal FDA rulemaking and is not approval.
- Goals discussed
- Healing & Recovery, Skin & Glow, Heart, Liver & Kidney
- Also called
- Ac-LKKTETQ, Thymosin beta-4 fragment (LKKTETQ), TB500, horse peptide, TB (as "BPC/TB")
- Last reviewed
- 2026-10-11
- Synthetic peptide based on the active actin-binding region of thymosin beta-4 (Tβ4), a natural 43-aa protein that regulates actin, cell migration and angiogenesis; most research is on full Tβ4, not TB-500; not FDA-approved and prohibited by WADA (S2).12
TB-500 is sold as a synthetic fragment of thymosin beta-4 (identified in WADA-funded work as Ac-LKKTETQ); most published research tests full-length thymosin beta-4, not TB-500.
Regulatory status Not FDA-approved; in July 2026 an FDA advisory panel voted 8-6 to recommend letting pharmacies compound TB-500, reviewed for wound healing, a nonbinding recommendation that still requires formal FDA rulemaking and is not approval. 3
Names as used in gyms, forums and gray-market listings. Reported, not endorsed; stacks have not been studied as combinations.
Human evidence was concentrated in ocular/cornea and wound/skin/soft tissue settings, whereas direct TB-500 evidence was limited to a single included study.
Scoping review of 80 studies on thymosin beta-4 and TB-500, most of them preclinical.
What is TB-500 researched for?
The three outcomes most discussed for TB-500 in the sources below, as those sources report them. humanpeptides.fyi makes no claims of its own: a listed benefit can be unproven or can have failed in trials, and the label on each line says which.
What do researchers and users say about TB-500?
This drug has no place in racing, its use is easily detected in the thoroughbred and its administration to a racehorse would be viewed very seriously.
Australian racing regulator on TB-500 during 2013 allegations that NRL players had been given the peptide.
There's no way to know what the substance actually is, was or will be tomorrow because that name has no legal meaning
Said at FDA's July 2026 compounding advisory meeting about substances such as TB-500 that are not recognized pharmaceutical ingredients in the U.S.
What side effects of TB-500 are reported?
- No completed human safety data for injectable TB-500; user-reported injection reactions, fatigue, headache, nausea, dizziness; theoretical tumor-growth concern from angiogenesis/cell migration; WADA-prohibited21213
- Possible immune reactions (immunogenicity) from aggregation or peptide impurities in compounded products; FDA identified no human exposure dataFDA assessment14
What do peptide guides say about TB-500?
- Dr. Axe Dr. Axe's guide rates TB-500 as insufficient evidence, stressing that it is a fragment distinct from full-length thymosin beta-4 and that FDA reports no identified human exposure data for it. 15
- PepEdHub PepEdHub's profile describes TB-500 as a synthetic version of thymosin beta-4 that upregulates actin to drive cell migration, promotes new blood vessels, lowers inflammatory cytokines and activates muscle satellite cells. 16
- Seek Peptides Seek Peptides promotes TB-500 mainly for tendon, ligament and chronic injury healing, also claiming better flexibility, less scar tissue and, as a secondary effect, hair growth. 17
- NCBI PMC Human data mostly involve full-length thymosin beta-4: in a 72-person dry eye trial of eye drops, both primary endpoints were missed, some secondary measures improved, and no adverse events occurred. 18
What does the research say, system by system?
How strong is the evidence for TB-500?
Tβ4: animal + some human phase 2 (eye, skin, heart); TB-500 itself: almost no direct evidence, mainly anecdotal
Mostly cell and animal studies. Human effects unknown. How tiers work
Questions about TB-500
What is TB-500?
Synthetic peptide based on the active actin-binding region of thymosin beta-4 (Tβ4), a natural 43-aa protein that regulates actin, cell migration and angiogenesis. TB-500 is sold as a synthetic fragment of thymosin beta-4 (identified in WADA-funded work as Ac-LKKTETQ); most published research tests full-length thymosin beta-4, not TB-500.
Is TB-500 FDA-approved?
Not FDA-approved; in July 2026 an FDA advisory panel voted 8-6 to recommend letting pharmacies compound TB-500, reviewed for wound healing, a nonbinding recommendation that still requires formal FDA rulemaking and is not approval.
What is TB-500 researched for?
The sources cited on this page most often discuss three outcomes: Wound healing, mostly preclinical; Cardiac repair, preclinical; Injury recovery, anecdotal. Each line above shows what the source reports and how strong that evidence is.
What side effects of TB-500 are reported?
Reported in the cited sources: No completed human safety data for injectable TB-500; user-reported injection reactions, fatigue, headache, nausea, dizziness; theoretical tumor-growth concern from angiogenesis/cell migration; WADA-prohibited; Possible immune reactions (immunogenicity) from aggregation or peptide impurities in compounded products; FDA identified no human exposure data. The list is not complete, and few listed risks does not mean a compound is safe.
How strong is the evidence for TB-500?
Evidence label: Preclinical. Tβ4: animal + some human phase 2 (eye, skin, heart); TB-500 itself: almost no direct evidence, mainly anecdotal.
What else is TB-500 called?
Names used for it include Ac-LKKTETQ, Thymosin beta-4 fragment (LKKTETQ), TB500, horse peptide, TB (as "BPC/TB").
Does humanpeptides.fyi recommend TB-500?
No. humanpeptides.fyi makes no claims and no recommendations of its own. It summarizes and links to what others have published and posted. Nothing here is medical advice; talk to a licensed clinician.