Is TB-500 considered natty?

TB-500 is generally regarded as compatible with natural bodybuilding. Most sanctioning bodies do not prohibit its therapeutic use, though rules vary by federation.

Is TB-500 on the WADA prohibited list?

As of the current prohibited list, TB-500 is not explicitly banned by WADA, though regulations can change. Always verify against the current year's WADA prohibited list before competition.

How is TB-500 administered?

TB-500 is typically administered via: subcutaneous injection. Dosage and administration protocols vary; see the Dosage section for details.

TB-500 - Retapedia | Natty or Not?

Medical disclaimer. This article is for informational purposes only and does not constitute medical advice. Consult a qualified clinician before considering any compound discussed below. See Retapedia : Medical disclaimer.

TB-500
Structure of TB-500. Marketed TB-500 is the N-acetylated heptapeptide Ac-LKKTETQ, corresponding to residues 17–23 of human thymosin β-4. Source: PubChem CID 62707662.
Identification
Class	Modified peptide
PubChem CID	62707662
Other names	TB-500 · Thymosin Beta-4 · Tβ4
Trade names	TB-500 Peptide Thymosin Beta-4 TB-500 Injectable
Administration
Routes	Subcutaneous injection
Status
Verdict	Natty
WADA	Not prohibited^[3]
Article meta
Slug	`tb-500`
Last edited	May 25, 2026
Tags	healing, recovery, tissue repair, anti-inflammatory, injectable, subcutaneous

TB-500 (also known as TB-500 or Thymosin Beta-4 or Tβ4) is a therapeutically researched peptide studied for its effects on healing, recovery, tissue repair. Synthetic peptide based on thymosin beta-4 promoting tissue repair, wound healing, and muscle recovery through actin regulation. Strong animal research, limited human data. Not FDA-approved.

TB-500 is a synthetic 43-amino acid peptide modeled after thymosin beta-4 (Tβ4), a naturally occurring protein found throughout the human body that plays critical roles in tissue regeneration, wound healing, and inflammation modulation. Its primary mechanism involves binding to actin, a protein essential for cell structure and movement, thereby promoting cell migration, angiogenesis (new blood vessel formation), and tissue remodeling. TB-500 has demonstrated significant potential in preclinical studies for accelerating soft tissue repair, enhancing wound closure, improving cardiovascular function post-injury, supporting muscle and tendon recovery, and promoting neuroregeneration.

Natty status

TB-500 is generally regarded as compatible with natural bodybuilding, though competitive federations may differ. See § Natty status.

Contents [hide]

1 Overview
2 Mechanism of action
3 Reported effects
4 Dosage and administration
5 Natty status
6 Research
7 Related compounds
8 References
9 External links

Overview

The peptide works by reducing pro-inflammatory cytokines while promoting anti-inflammatory mediators, creating an optimal regenerative environment.

Research has shown benefits in cardiac protection following myocardial infarction, enhanced muscle fiber repair after strain or trauma, accelerated dermal and epithelial wound healing with reduced scarring, improved joint flexibility and tendon resilience, and potential neuroprotective effects in models of spinal cord and peripheral nerve injury.

However, like BPC-157, TB-500 lacks substantial human clinical trial data and is not FDA-approved for therapeutic use.

It is classified as a prohibited substance by the World Anti-Doping Agency (WADA) and remains designated for research use only.

Quality control concerns exist as it is an unregulated compound in most jurisdictions.

While animal studies suggest it is generally well-tolerated, comprehensive human safety data is limited.

Mechanism of action

Speeds wound healing, muscle and tendon recovery. Reduces inflammation, improves joint mobility, minimizes scar tissue formation.

Reported effects

Effects reported in the literature and from preclinical models include:

TB-500 (thymosin beta-4 fragment) demonstrates favorable tissue repair and musculoskeletal healing outcomes in animal models, supporting its use as a soft-tissue recovery agent in preclinical sports medicine research. ^[2] Preclinical
Identified in a 2026 gerontology review as one of nine therapeutic peptides targeting aging hallmarks, with TB-500 specifically noted for tissue repair applications and promising preclinical evidence. ^[1] Preclinical
Unapproved peptide therapies including TB-500 are increasingly used for accelerated injury recovery and performance enhancement, though rigorous human safety and efficacy data remain scarce. ^[2] Anecdotal

Evidence grades: FDA approved Phase III Phase II Phase I Preclinical Anecdotal

Dosage and administration

⚠

Dosage information is included for encyclopedic purposes only. Retapedia does not provide medical advice. See Retapedia : Medical disclaimer.

Subcutaneous

Loading Phase: 2-2.5mg twice weekly for 4-6 weeks
Maintenance: 2mg once weekly or 5mg every 2 weeks
Acute Injury: 2.5mg twice weekly for 2-4 weeks, then reduce

Can be combined with BPC

157 for enhanced tissue repair

Typical cycle

4-8 weeks loading, followed by maintenance or off-period

General

Inject subcutaneously in abdomen, thigh, or near injury site
Reconstitute with bacteriostatic water, store refrigerated 2-8°C
Use within 30 days after reconstitution

Natty status

See also: Peptide § Natty status

TB-500 is generally regarded as compatible with the natty designation, particularly when used for therapeutic healing purposes. Opinions vary across natural bodybuilding federations, and athletes who compete should consult the rulebook of their respective sanctioning body.^[3]