TB-500
Promoted for wound healing and recovery, but NOT FDA-approved and on the FDA safety-risk list. Robust human evidence is lacking.
This peptide is not FDA-approved for any indication. Human use outside of clinical trials is not recommended.
The basics
- Generic Name
- thymosin beta-4 fragment (TB-500 / LKKTETQ)
- Brand Names
- None (not an approved product)
- Regulatory Status
- Early Research
- Therapeutic Areas
- Musculoskeletal, Immune & Recovery
Wellness Goals
Important: This peptide is not yet FDA-approved
TB-500 has not been approved by the FDA for any use in humans. That means it hasn't gone through the rigorous testing process that confirms a drug is safe and effective. Products sold online have not been evaluated by any regulatory body.
Heads up: The FDA has flagged some safety concerns with this one. That doesn't mean it's definitely dangerous, but it means we don't know enough yet.
What it does
TB-500 (thymosin beta-4 fragment (TB-500 / LKKTETQ)) is a synthetic peptide that researchers are studying, but it's not yet FDA-approved for any human use. A synthetic fragment of thymosin beta-4. Proposed to promote wound healing and tissue repair through effects on cell migration and angiogenesis, but robust human evidence is lacking.
The research is still early. Most studies so far are in animals or lab settings, so we don't know for sure how well this translates to real-world results in people.
How it's taken
Subcutaneous injection
How people access it
Category 1 compounding-eligible since February 2026. Requires a doctor's prescription sent to a licensed compounding pharmacy. Not available at retail pharmacies.
Regulatory Status
Not FDA-approved. FDA lists thymosin beta-4 fragment (LKKTETQ) among substances that may present significant safety risks for compounding.
FDA Safety-Risk Designation
This substance appears on the FDA's list of substances that may present significant safety risks when used in compounding. This designation indicates that the FDA has identified concerns about the safety of this substance that have not been adequately addressed through clinical testing.
Any use in humans outside of an FDA-authorized clinical trial would require an Investigational New Drug (IND) application. Products marketed as “for research use only” are not legally intended for human administration.
What the Evidence Shows
The evidence base for TB-500 consists primarily of preclinical studies (animal models and in vitro experiments). There are no completed, large-scale, peer-reviewed clinical trials establishing safety or efficacy in humans. The gap between promising animal data and proven human benefit is substantial — many compounds that show effects in animal studies fail to demonstrate safety or efficacy in human trials.
Marketing claims made by online sellers and “peptide clinics” frequently overstate the evidence and omit critical information about risks and unknowns.
Other options to consider
Depending on what you're hoping to achieve, there may be FDA-approved treatments that have been rigorously tested and proven to work. Discuss evidence-based options with your own healthcare provider to find what fits your specific goals.
Browse our full peptide directory to see FDA-approved options that might work for you.
Common Questions
TB-500 is not an FDA-approved drug and cannot be legally marketed for human use in the United States. It is sometimes sold labeled "for research use only," but this label does not make it legal for human consumption. The FDA has listed thymosin beta-4 fragment among substances that may present significant safety risks for compounding.
The evidence for TB-500 in humans is extremely limited. Most studies involve thymosin beta-4 (the parent protein) in animal models or cell culture. There is insufficient clinical evidence to support claims about wound healing, recovery, or tissue repair in humans. Marketing claims far exceed the available scientific evidence.
The FDA maintains a list of substances that present significant safety risks when used in compounding. TB-500 (thymosin beta-4 fragment LKKTETQ) appears on this list because of insufficient characterization data, lack of adequate safety studies in humans, and concerns about the quality and consistency of compounded preparations.
Curious about what IS approved?
Check out FDA-approved peptides that address similar goals — with established safety profiles and real clinical evidence.
See Approved Options