Editorial review: Medriva pages are written by named contributors, reviewed by clinical or subject-matter experts, and updated as evidence or regulatory status changes.

TB-500 Fragment: Evidence, Side Effects, and Regulatory Status (2026)

Q: Is TB 500 Fragment FDA approved?

Not FDA approved. See the regulatory status section above for details.

Q: Does TB 500 Fragment work for healing and recovery?

Evidence is anecdotal . See the linked use case hub for the full breakdown.

Q: How much does TB 500 Fragment cost?

See the cost pages or the GLP 1 price/supply tracker where applicable.

TB-500 Fragment is Not FDA-approved. Evidence grade: anecdotal. This page is clinically reviewed.

TL;DR / Quick Facts

TB-500 Fragment is The TB-500 fragment is a sub-fragment of Thymosin β-4, marketed in some peptide clinics. Not FDA-approved. The fragment is distinct from full TB-500 / Thymosin β-4. FDA status: Not FDA-approved. Typical use cases: healing and recovery. Evidence grade: anecdotal. Dosing is not established (no FDA-approved protocol). Common side effects: see below. Medriva editorial stance: this compound has limited human evidence; consult a licensed clinician.

What it is

TB-500 Fragment is a member of the Thymosin β-4 fragment class. Subset of the actin-binding domain of Thymosin β-4. Pharmacological claim is extrapolated from full-length Thymosin β-4 data.

What the evidence says

Evidence for TB-500 Fragment is anecdotal. The bulk of the evidence is from pre-clinical models and small or uncontrolled human studies. Well-controlled phase 3 trials are limited or absent.

[Detailed evidence breakdown in the corresponding claim or pillar pages is linked at the bottom of this page.]

What it's used for

Commonly discussed uses of TB-500 Fragment:

Healing And Recovery — anecdotal evidence.

For the full list, see the linked use-case hubs below.

Dosing is unestablished

No FDA-approved dosing protocol exists for TB 500 Fragment. Published research and clinic-marketed protocols are not interchangeable with medical guidance. Medriva does not publish dosing instructions for research-use or non-approved compounds. Review quality controls with a licensed clinician and use the vendor evaluation framework and COA explainer before considering any source.

Side effects and risks

Common: Side effects vary by compound and indication; review the approved label or profile-specific safety data with a clinician.
Serious: Seek urgent care for severe allergic symptoms, chest pain, severe abdominal pain, persistent vomiting, or other severe reactions.
Long-term unknowns: For non-approved or research-use compounds, long-term human safety data may be limited.

Regulatory status

FDA-approved use(s): None. RUO.
Compounded availability: see 503A vs 503B explainer
Research-use-only (RUO) availability: yes
Banned in sport: see WADA & sports explainer

Cost and access

TB-500 Fragment is available primarily via telehealth platforms and 503A compounding pharmacies. For pricing, see our cost pages or the GLP-1 price/supply tracker where applicable.

Who it might be appropriate for

Adults with a relevant diagnosed condition or clinical goal, under the supervision of a licensed clinician, who have no contraindications. TB-500 Fragment is not for self-experimentation.

Who should not use it

Contraindications vary by compound, indication, pregnancy status, comorbidities, and current medications. For the full list, see the contraindications checklist and discuss with your clinician.

Medriva editorial stance

We describe the literature. We do not promote TB-500 Fragment as a cure, treatment, or performance enhancer. We do not recommend it for self-experimentation. We do recommend that readers (a) understand the evidence grade (anecdotal), (b) understand the regulatory status (Not FDA-approved), and (c) discuss with a licensed clinician before acting.

How to talk to a clinician

See our guide on how to talk to a clinician for a templated conversation.

Frequently Asked Questions

Is TB-500 Fragment FDA-approved?

Not FDA-approved. See the regulatory status section above for details.

Does TB-500 Fragment work for healing and recovery?

Evidence is anecdotal. See the linked use-case hub for the full breakdown.

What are the side effects?

See the side effects section above. Discuss with your clinician.

How much does TB-500 Fragment cost?

See the cost pages or the GLP-1 price/supply tracker where applicable.

Can I buy TB-500 Fragment online?

Only via prescription from a 503A compounding pharmacy or a licensed telehealth platform. Medriva does not sell peptides and does not endorse RUO vendors.

Author + Clinical reviewer

Author: Elena Park, PharmD Clinical reviewer: Jonathan Reeves, MD Last reviewed: 2026-06-05

Next steps

Review the evidence grade and regulatory status before making decisions about TB 500 Fragment.
Bring this page to a licensed clinician if you are discussing benefits, risks, or alternatives.
Subscribe to the Medriva Peptide Brief for evidence and regulatory updates.

Related use-case hubs

Peptides for Healing And Recovery

Related comparisons

Editorial process

This page follows the Medriva Editorial Policy and the Clinical Review Methodology. Page last reviewed: 2026-06-05. Author: Elena Park, PharmD. Clinical reviewer: Jonathan Reeves, MD.

Current source updates

For new regulator actions, compounding-policy changes, warning letters, shortage updates, and sports-rule changes, review the Peptide Tracker before relying on older summaries.