Peptide Encyclopedia / TB-500
EncyclopediaTB-500 is a synthetic peptide sold as a fragment of thymosin beta-4, the actin-binding protein linked to tissue repair. Almost all of that repair evidence comes from animal models, human data on the marketed fragment is essentially absent, and it is not FDA-approved, sold only as a research chemical and banned in sport. Below you'll find reported dosing, reconstitution, cycling, and the safety and legal lines. Educational only, not medical advice.
| Also known as | TB-500, Thymosin Beta-4 fragment, T-beta-4 fragment, Tb4 fragment |
| Regulatory status | NOT FDA-approved for any indication. |
NOT FDA-approved for any indication. TB-500 is a synthetic peptide marketed as a fragment/analog of the actin-binding region of thymosin beta-4 (Tb4). It is sold only as an unapproved research chemical not intended for human use and is prohibited in sport. WADA includes TB-500 / thymosin beta-4-related substances under the Prohibited List section S2 (peptide hormones, growth factors and related substances), banned both in and out of competition. The full-length Tb4 molecule has been studied in registered clinical trials but is also not FDA-approved.
Thymosin beta-4 is a naturally occurring 43-amino-acid peptide and the major actin-sequestering molecule in mammalian cells. TB-500 corresponds to the actin-binding domain. Proposed mechanisms (from Tb4 research) include binding and regulating G-actin to promote cell migration, down-regulation of inflammatory chemokines and cytokines, promotion of angiogenesis (blood-vessel formation), cell survival, and stem-cell maturation, collectively supporting tissue repair and regeneration. Pharmacokinetics (half-life No verified definitive human pharmacokinetic half-life for TB-500 is established (unapproved agent). Pharmacokinetics of full-length Tb4 have been examined in early-phase studies but are not standardized into an FDA label.): Because TB-500 is an unapproved research chemical, no FDA-reviewed pharmacokinetic labeling exists. Human PK data come only from investigational studies of full-length thymosin beta-4 (e.g., intravenous dosing in cardiac trials), which may not translate directly to the marketed fragment.
Evidence for tissue-repair effects is predominantly from animal models; human evidence for the marketed TB-500 fragment is essentially absent. Full-length thymosin beta-4 has entered registered clinical trials (e.g., acute myocardial infarction, ophthalmic indications), but no completed pivotal trial supports approved use, and the specific 'TB-500' fragment sold to consumers has not been validated in human efficacy trials. Reported use: Reported (not approved) community and clinic use describes subcutaneous injection in milligram amounts, often with a 'loading' phase of several injections per week for a few weeks followed by less frequent 'maintenance' dosing, frequently stacked with BPC-157 for injury recovery. These regimens are not derived from any FDA label or controlled human efficacy trial, vary widely, and are not validated or prescriptive. Reported only.
Human safety of the marketed TB-500 fragment is not established. There are theoretical concerns that angiogenesis-promoting and pro-proliferative activity could be harmful in the setting of malignancy. Product identity, purity, sterility, and dose accuracy are unverified when obtained as a research chemical, posing infection and contamination risks. It is banned in sport (WADA S2). No FDA-reviewed safety labeling exists..
Active or suspected malignancy (theoretical concern via angiogenesis/proliferation; no verified clinical source), Pregnancy and lactation (not studied).
No verified source found for established drug-drug interactions
Log every dose and injection site, get the reconstitution and units math automatically, follow your cycle, and record how you feel, then export a provider report. TB-500 tracker, free to start.
PepWise is an informational and educational tracking tool, not medical advice and not a medical device. TB-500 may be experimental, restricted, or prescription-only; many research peptides are not FDA-approved. Consult a licensed healthcare provider before starting, changing, or stopping any protocol. Operated by STC Consulting, Inc.
