Is TB-500 Fragment (17-23) Legal? FDA Status and Regulations Explained (2026)

Key Takeaways

• TB-500 Fragment (17-23) is not FDA-approved and is available for research purposes only.
• The peptide is not listed on the FDA's compounding bulk drug substance list, prohibiting its use in compounding pharmacies.
• It can be sold legally for research use, but not for therapeutic applications.
• Patients should verify that clinics offering TB-500 Fragment (17-23) are operating within legal boundaries.

Current FDA Status

TB-500 Fragment (17-23) is not approved by the FDA for any therapeutic use. It is classified as a research-only compound, meaning it is primarily used in laboratory settings to study its effects on wound repair, tissue remodeling, and regenerative signaling. The peptide is derived from the actin-binding region of Thymosin Beta-4 and modulates actin polymerization to regulate cell migration and angiogenesis. As of the last update, TB-500 Fragment (17-23) is not included in the FDA's compounding bulk drug substance list (Category 1, 2, or 3) as per the Federal Register FDA-2016-D-1307.

Compounding Status

TB-500 Fragment (17-23) is not eligible for compounding under either 503A or 503B pharmacy regulations due to its exclusion from the FDA's approved list of bulk drug substances. This exclusion is based on the lack of sufficient safety and efficacy data required for such a designation. Compounding pharmacies are prohibited from using substances not listed in Category 1 of the FDA's list, which includes substances that are eligible for compounding based on clinical need and safety data.

Enforcement Actions

To date, there have been no specific DOJ prosecutions or FDA warning letters directly related to TB-500 Fragment (17-23). However, the FDA has issued warnings to companies marketing unapproved peptides for therapeutic use, which could potentially apply to TB-500 Fragment (17-23) if marketed inappropriately. For instance, the FDA's warning letter to a peptide supplier in 2024 highlighted the illegal marketing of research peptides for non-research purposes (FDA Warning Letter, 2024).

Prescription vs. Over-the-Counter vs. Research Use

TB-500 Fragment (17-23) is available legally for research use only, which means it can be purchased by laboratories and researchers for scientific studies. It cannot be prescribed by healthcare providers for therapeutic use, nor can it be sold over-the-counter. "Research use only" implies that the peptide is not intended for human consumption or therapeutic application, and any sale or use outside this scope is considered illegal.

State-Level Variations

Currently, there are no significant state-level variations in the regulation of TB-500 Fragment (17-23). Most states adhere to federal guidelines regarding the sale and use of research chemicals. However, state-level enforcement may vary, and it is advisable to check specific state regulations if considering research applications.

What "Off-Label" Actually Means

The term "off-label" applies to FDA-approved drugs prescribed for non-approved indications. Since TB-500 Fragment (17-23) has never received FDA approval, it cannot be prescribed off-label. Any prescription of this peptide constitutes the use of an unapproved drug, which is not permissible under current regulations.

What This Means for Patients

Patients seeking peptide therapy involving TB-500 Fragment (17-23) should exercise caution. Verify that any clinic offering this peptide is compliant with legal standards and operating as a research facility rather than a therapeutic provider. Red flags include clinics claiming therapeutic benefits or offering the peptide without clear research protocols.

Legal Alternatives

Given the legal limitations of TB-500 Fragment (17-23), patients may consider FDA-approved alternatives for similar conditions. For instance, BPC-157 is another peptide with regenerative properties under investigation, though it also remains in the research phase.

FAQ

Is TB-500 Fragment (17-23) approved for human use?

No, TB-500 Fragment (17-23) is not approved for human use and is available for research purposes only.

Can TB-500 Fragment (17-23) be compounded by pharmacies?

No, it is not listed on the FDA's approved compounding list, prohibiting its use in both 503A and 503B compounding pharmacies.

What does "research use only" mean for TB-500 Fragment (17-23)?

"Research use only" means the peptide can be used in laboratory settings for scientific studies but not for therapeutic applications or human consumption.

Are there any legal alternatives to TB-500 Fragment (17-23)?

While TB-500 Fragment (17-23) is not approved, peptides like BPC-157 are under research for similar uses.

How can I ensure a clinic is legally offering TB-500 Fragment (17-23)?

Ensure the clinic is registered as a research facility and does not advertise therapeutic benefits of TB-500 Fragment (17-23).

Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice. Consult a licensed healthcare provider before starting any treatment. Legal status can change and was last verified February 2026.