--- title: "TB-500: what sources report" url: https://humanpeptides.fyi/peptides/tb-500 site: humanpeptides.fyi last_reviewed: 2026-10-11 --- # TB-500 > humanpeptides.fyi makes no claims of its own. Every statement below reports what a cited source says, with its link. Not medical advice. 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. ## At a glance - **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 ## 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; most research is on full Tβ4, not TB-500; not FDA-approved and prohibited by WADA (S2). Sources: , 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. Source: ## What is TB-500 researched for? ### 1. Wound healing, mostly preclinical - Wound/soft-tissue healing: Tβ4 promotes cell migration, angiogenesis and wound closure; human evidence mostly ocular (cornea) and skin wounds, musculoskeletal data sparse; direct TB-500 evidence limited to one study (scoping review of 80 studies, mostly preclinical) Sources: , - Goals: [Healing & Recovery](https://humanpeptides.fyi/objectives/healing), [Skin & Glow](https://humanpeptides.fyi/objectives/skin) ### 2. Cardiac repair, preclinical - Cardiac repair: Tβ4 reduced fibrosis/scarring after cardiac injury in mice; recombinant Tβ4 in a 96-patient STEMI RCT reduced infarct area only in the early-dosed subgroup (overall not significant) (animal + human RCT, mixed) Sources: , , - Goals: [Heart, Liver & Kidney](https://humanpeptides.fyi/objectives/organs) ### 3. Injury recovery, anecdotal - Anecdotal injury recovery (usually stacked with BPC-157): Reddit users report less pain/swelling over 3-12 weeks for tendon, meniscus, ankle injuries; some no benefit (anecdotal/Reddit) Sources: , - Goals: [Healing & Recovery](https://humanpeptides.fyi/objectives/healing) ## What do researchers and users say about TB-500? > "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." > > McGuire F, et al., Thymosin Beta-4 and TB-500 in Tissue Healing, Regeneration, and Musculoskeletal Repair: A Scoping Review (Applied Sciences, 2026). Context: Scoping review of 80 studies on thymosin beta-4 and TB-500, most of them preclinical. > "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." > > Ray Murrihy, Racing NSW chief steward, Even horses don't use banned drug (Daily Telegraph, via news.com.au, 2013). Context: 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" > > Russell Wesdyk, associate director, FDA drug center, FDA advisory panel narrowly backs use of several peptides favored by RFK Jr. (AP via PBS NewsHour, 2026). Context: 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-prohibited Sources: , , - Possible immune reactions (immunogenicity) from aggregation or peptide impurities in compounded products; FDA identified no human exposure data (FDA assessment) Sources: ## 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. - **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. - **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. - **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. ## What does the research say, system by system? ### Body & tissues - Skin/wounds, cornea, blood vessels, bone most studied; tendon, ligament, muscle, cartilage data sparse (scoping review) Sources: - Reduced liver fibrosis and lung damage in animal models Sources: ### Hormones & physiology - Anti-inflammatory: Tβ4-sulfoxide disperses inflammatory macrophages and inhibits interferon-gamma in human immune-cell co-cultures (in vitro/animal) Sources: - Pro-angiogenic via VEGF, HIF, PI3K/Akt/eNOS signaling Sources: ### Cells & mitochondria - Actin sequestration drives cell migration; Tβ4 reported to act via ATP synthase receptor (purinergic signaling); reduced cardiomyocyte apoptosis via ErbB2 (in vitro/animal) Sources: , ### Brain, mood & sleep - Tβ4 has shown preclinical efficacy in brain injury models with repeated dosing (animal, cited in review) Sources: ### Muscle - No direct data; musculoskeletal/muscle repair evidence is comparatively sparse (scoping review) Sources: ### Also notable - Tβ4-overexpressing mice had increased hair growth (animal) Sources: - Bell-shaped dose response: higher doses sometimes less effective Sources: ## How strong is the evidence for TB-500? **Preclinical** (2 of 5). 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._ ## Street names and stacks - Street names: [TB](https://humanpeptides.fyi/street-names#nick-tb) - Appears in community stacks: [The Wolverine Stack](https://humanpeptides.fyi/street-names#wolverine-stack) ## 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. --- Family: [Repair & Recovery](https://humanpeptides.fyi/peptides?cat=repair). HTML version: . Disclaimer: