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Research peptide — not a dietary supplement
TB-500 is a research compound, not a regulated dietary supplement. It is typically administered by injection and sold “for research use only.” The evidence below is largely preclinical (animal and in-vitro) or early-stage, so no evidence score is assigned. This page is provided for transparency and education — it is not a recommendation to use. Consult a qualified healthcare provider, and be aware that purity, dosing, and legal status vary by jurisdiction.
What the evidence says
Most TB-500 studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from mixed-quality randomised trials published 1990–2022 with a typical study size of 18 participants.
Based on 13 studies · 2 RCTs · 701 total participants
Confidence
LowBy outcome
The current evidence for TB-500 is insufficient to assign an evidence score, based on 13 indexed studies. A grey-market injectable peptide sold as a synthetic fragment of thymosin β-4 (Tβ4), an endogenous actin-sequestering protein. Honest appraisal: the regenerative claims rest almost entirely on animal and cell studies of the parent peptide Tβ4 (cardiac, wound, tendon, liver, eye). There are NO published human efficacy-safety RCTs of 'TB-500' itself — only early-phase Tβ4 trials in dermal ulcers and the eye, a tiny retrospective injection case-series, and biomarker cohorts. Research-use-only; banned in sport (WADA). Representative study: PMID 36613994.
The commonly studied dose of TB-500 is No validated human dose. Grey-market protocols (subcutaneous, e.g. 2-2.5 mg twice weekly) are anecdotal and not supported by any human trial.. Individual needs vary — start at the lower end of the range and adjust based on how you respond.
Semaglutide
Mostly mechanism / observationalAn FDA-approved GLP-1 receptor agonist (Ozempic/Rybelsus for type 2 diabetes, Wegovy for chronic weight management) with genuinely strong, large-RCT evidence for glycemic control and substantial weight loss, plus a cardiovascular-outcomes benefit. Honest appraisal: this is a real prescription medicine with real efficacy AND real risks — a boxed warning for thyroid C-cell tumors, pancreatitis and gallbladder risk, very common GI side effects, and growing concern about grey-market/compounded versions. It is included here for reference only, not as a supplement and not auto-recommended.
Last reviewed June 2026 · evidence from 13 studies · how we score
This information is for educational purposes only. It is not a substitute for professional medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication.
TB-500 (Thymosin β-4 fragment)
A grey-market injectable peptide sold as a synthetic fragment of thymosin β-4 (Tβ4), an endogenous actin-sequestering protein. Honest appraisal: the regenerative claims rest almost entirely on animal and cell studies of the parent peptide Tβ4 (cardiac, wound, tendon, liver, eye). There are NO published human efficacy-safety RCTs of 'TB-500' itself — only early-phase Tβ4 trials in dermal ulcers and the eye, a tiny retrospective injection case-series, and biomarker cohorts. Research-use-only; banned in sport (WADA).
Regenerative claims rest almost entirely on animal and cell studies of the parent peptide Tβ4; there are no human RCTs of injectable TB-500 for its marketed musculoskeletal uses.
TB-500 is a research peptide marketed to athletes and biohackers as a synthetic, more 'stable' fragment of thymosin β-4 (Tβ4) — a small (~5 kDa), naturally occurring actin-sequestering peptide released by platelets and many cell types after injury.
The honest evidence picture is that essentially all of the regenerative biology attributed to TB-500 comes from preclinical work on the parent peptide Tβ4: it binds G-actin and modulates cell migration, promotes angiogenesis, reduces inflammation and myofibroblast-driven scarring, and in animal models improves cardiac repair after infarction, accelerates dermal wound healing, and modulates liver fibrosis.
These are predominantly animal and in-vitro findings. Human data are minimal and do NOT concern the grey-market 'TB-500' product: pharmaceutical-grade Tβ4 (e.g.
RGN-259) reached Phase 2/3 trials for dermal ulcers and ocular surface disease (dry eye, neurotrophic keratopathy), endogenous circulating TB4 has been studied as a cardiovascular biomarker, and there is one small retrospective chart review of intra-articular BPC-157 ± TB4 for knee pain.
There are no adequately powered, published randomized controlled trials establishing the efficacy or safety of injectable TB-500 in humans for muscle/tendon recovery — the uses for which it is actually sold.
Because Tβ4 is pro-angiogenic and can promote tumor cell migration and chemoresistance in cancer-cell models, there is a genuine theoretical oncologic concern. TB-500 is not a regulated dietary supplement, carries the sourcing/purity risks of any grey-market injectable, and is prohibited in sport by WADA.
Overall human evidence for the marketed product is effectively absent; the score reflects preclinical-only signal.
Tβ4 forms a 1:1 complex with monomeric G-actin, buffering the pool of polymerizable actin and thereby regulating the actin cytoskeleton and cell motility. This is the only Tβ4 activity with a well-defined molecular mechanism.
By remodeling the actin cytoskeleton, Tβ4 promotes migration of endothelial and progenitor cells and new blood-vessel formation in preclinical models — central to its proposed repair effects but also the basis of a theoretical tumor concern.
In animal and cell studies Tβ4 lowers inflammatory mediators and reduces myofibroblast numbers and scarring; it is also the precursor of the regulatory tetrapeptide AcSDKP.
How TB-500 works — from molecular targets to health outcomes. Click an edge to see supporting research.This visualization is in beta — pathways are being refined and expanded.
Tap node to isolate • Pinch to zoom • Tap edge for research
No validated human dose. Grey-market protocols (subcutaneous, e.g. 2-2.5 mg twice weekly) are anecdotal and not supported by any human trial.
Can be taken without food
| Form | Type |
|---|---|
| 💊Lyophilized peptide for subcutaneous injection | Recommended |
Pharmaceutical-grade thymosin β-4 (e.g. RGN-259) used in clinical trials is not the same as grey-market 'TB-500'.
Minimum: 4 weeks
Optimal: 8 weeks
Cycling: Not required
Note: Injectable; no validated timing. All dosing guidance is anecdotal.
Dose-response data unavailable. The current published research for TB-500 does not provide sufficient dose-specific outcome data to generate reliable dose-response curves.
Refer to the Dosage & Timing section above for recommended dose ranges based on available evidence.
Accelerated cardiac, dermal and other tissue repair — demonstrated in animal/cell models of Tβ4, not in controlled human trials of TB-500.
No published randomized controlled trials of injectable TB-500 for muscle/tendon recovery — the marketed use. Human Tβ4 trials exist only for skin ulcers and the eye.
Tβ4 is pro-angiogenic and promotes tumor-cell migration / chemoresistance in cancer-cell models — a real theoretical risk in anyone with or at risk of cancer.
Avoid — Tβ4 is pro-angiogenic and promotes tumor-cell migration in models.
Avoid — not established as safe in human pregnancy.
Prohibited by WADA — use risks an anti-doping violation.
Cell-model data show Tβ4 can inhibit caspase-3 activation and confer paclitaxel resistance — a theoretical antagonism of chemotherapy and a pro-tumor concern. Avoid in anyone with or at risk of cancer.
Tip: Inherent to any self-injected grey-market peptide; sterility cannot be assured.
Tip: No human safety data for the marketed product — effects are unquantified.
Timing is flexible for TB-500 — consistent daily use matters more than the time of day. TB-500 is injected subcutaneously; no validated schedule exists.
TB-500 should be used with caution — talk to a healthcare provider before taking it. The most commonly reported side effects are injection-site reaction / infection, unknown long-term effects. Use caution if any of these apply to you: Pregnancy / breastfeeding; Active or prior cancer, or high cancer risk (theoretical pro-angiogenic / pro-metastatic concern); Competitive athletes subject to anti-doping (WADA-prohibited).
Tirzepatide
Mostly mechanism / observationalAn FDA-approved prescription medication (Mounjaro for type 2 diabetes, Zepbound for obesity and obstructive sleep apnea), not a dietary supplement. Honest appraisal: in head-to-head phase-3 trials it is the most effective approved weight-loss drug to date — up to ~21% body-weight loss over 72 weeks and superior to semaglutide — but it is a real medicine with real risks: a boxed warning for thyroid C-cell tumors, common GI side effects, and pancreatitis/gallbladder signals. Do not source or use it outside a prescription.