TB-500 (Ac-LKKTETQ) Dosage Guide, Benefits & Side Effects

Commonly reported mild effects include fatigue, dizziness, headache, and redness or irritation at the injection site. Less common but more serious reports include fever, rash, hives, blistering at the injection site, muscle aches, or gastrointestinal upset. There are no controlled human clinical trials establishing a full safety profile, so both the short- and long-term risks remain poorly characterized; any adverse reaction is generally advised to prompt discontinuation and medical evaluation.

As sold, TB-500 is typically a lyophilized (freeze-dried) powder that must be reconstituted with bacteriostatic or sterile water before use. Vendor and research-community guidance commonly recommends storing the unreconstituted powder frozen or refrigerated, and once reconstituted, keeping the vial refrigerated (roughly 2-8°C) and using it within about 2-4 weeks, avoiding freeze-thaw cycles and vigorous shaking of the solution.

TB-500 is not approved by the FDA (or equivalent regulators elsewhere) for human medical use and is sold in most markets labeled 'for research purposes only, not for human consumption.' It is also on the World Anti-Doping Agency (WADA) prohibited list, meaning it cannot be used by athletes subject to anti-doping testing. Buying, possessing, or using it as a human drug outside of a licensed research or clinical context may carry legal and regulatory risk depending on jurisdiction.

Most of the evidence for TB-500's healing effects comes from preclinical (animal and cell culture) studies of thymosin beta-4 and its fragment, which suggest roles in cell migration, angiogenesis, and reduced scarring. Human evidence is largely anecdotal, drawn from user reports and unregulated clinical use rather than peer-reviewed controlled trials, so claims of efficacy in humans have not been rigorously established and should not be treated as proven medical benefits.