- subcutaneous
- intramuscular
TB-500
Thymosin Beta-4 Fragment
TB-500 at a glance
Nomination withdrawnHow studies gave it
Injected into the fat under the skin, or injected into a muscle
Evidence on this page
2 peer-reviewed papers, published 2007 to 2016
FDA compounding lists
It was nominated for compounding use and the nomination was withdrawn.
Mixing it
TB-500 reconstitution calculatorWhat it is
TB-500 is a synthetic fragment of thymosin beta-4, a naturally occurring peptide present in most human and animal cells. It has been studied in animal models in the context of wound healing, tissue repair, and inflammatory response modulation. Preclinical research has explored its interactions with actin regulation and cell migration. It is widely discussed in biohacking communities focused on recovery.
Published research
Thymosin beta-4, the parent molecule of TB-500, has been studied in preclinical and limited clinical contexts. Animal studies have investigated its role in wound healing, cardiac tissue repair after injury, corneal healing, and modulation of inflammatory responses. Research has focused on its interaction with actin-binding and cell migration processes.
Some early-phase human studies have examined thymosin beta-4 in wound healing contexts, though TB-500 as a specific fragment has been studied primarily in animal models. Community-reported dosing is extrapolated from these research contexts.
What the terms on this page mean3 termsHide
- peptide
- A short chain of amino acids, the building blocks of proteins.
- animal model
- A test in animals standing in for the human condition. Results often fail to carry over to people.
- preclinical
- Laboratory and animal work done before any testing in people.
Compounding status
Nomination withdrawn- FDA lists it as
- Thymosin beta-4, fragment (LKKTETQ), also known as TB-500
- What that means
- These substances are not eligible for the policy that applies to substances in category 1. FDA would consider taking action against a compounder for compounding drug products with this bulk drug substance under its general enforcement policies.
Source: Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks, FDA. Content current as of 2026-04-22; read 2026-09-05. This describes what a compounding pharmacy may supply. It is not advice about your own use.
Also given subcutaneous
- TesamorelinTesamorelin Acetate (TH9507)Not on either FDA list
- Thymosin Alpha-1Thymosin Alpha-1 (Thymalfasin / Zadaxin)Nomination withdrawn
- Thymosin Beta-4Thymosin Beta-4 (Tβ4 / Timbetasin)Not on either FDA list
- ThymulinThymulin (Facteur Thymique Sérique / FTS / Nonathymulin)Not on either FDA list
- TirzepatideTirzepatide (dual GIP/GLP-1 receptor agonist)Not on either FDA list
- ACE-031Ramatercept (ActRIIB-IgG1 Fc Fusion Protein)Not on either FDA list
Where this came from2 referencesHide
Each one was resolved at PubMed and confirmed to be the work this page cites. Author, title, journal and year come from the PubMed record, not from the page text.
- Thymosin β4 Promotes Dermal Healing
Kleinman HK, Sosne G. Vitamins and hormones (2016). PMID 27450738.
- Development of thymosin beta4 for treatment of patients with ischemic heart disease
Crockford D. Annals of the New York Academy of Sciences (2007). PMID 17947592.
About this page
Reviewed 2026-08-11. This page reports what published studies and FDA documents say. It carries no dose, cycle length or stack, and it does not tell you whether a substance is appropriate for you. Side-effect reports circulating on forums are self-reported rather than measured, so they are not republished here.
See the editorial policy for how corrections are handled.