TB-500 regulatory status: Category 2 and the path forward

The proposal to return TB-500 to Category 1 is real. The reclassification itself is not yet effective.

TL;DR

• TB-500 was placed in FDA Category 2 following the 2023 PCAC vote, restricting its use in 503B bulk outsourcing facilities — pharmacies that manufacture larger batches without patient-specific prescriptions.
• A February 2026 HHS announcement proposed returning seven peptides — including TB-500 — to Category 1 for bulk compounding purposes, but the formal FDA Federal Register notice had not been published as of April 2026.
• TB-500 is available through Halftime Health under physician prescription through our licensed 503A compounding pharmacy partner, which prepares patient-specific medications on demand.

What it is

The FDA evaluates bulk drug substances for use in 503B outsourcing facilities — large-batch compounders that produce without patient-specific prescriptions. TB-500 was placed in Category 2 following the Pharmacy Compounding Advisory Committee’s 2023 review, meaning it is not approved for that bulk production pathway. The classification reflects an evidentiary determination — that adequate human safety and efficacy data was not available — rather than a finding of specific harm. 503A compounding pharmacies, which prepare individualized prescriptions on demand under physician supervision, operate under separate regulatory provisions.

How it works procedurally

The procedural pathway for moving a peptide between categories is the same as for any bulk drug substance: PCAC review and recommendation, FDA proposed rule or guidance published in the Federal Register, public comment period (typically 30–60 days), final FDA rule, and only then does the change become legally effective.

The February 2026 HHS announcement signaled the department’s intent to propose returning seven Category 2 peptides — including TB-500 — to Category 1. As of April 2026, the formal Federal Register notice initiating that process had not been published, and the next significant procedural milestone is the July 2026 PCAC meeting.

Who asks about it

People come to this topic when they have read news coverage suggesting TB-500 is “back” or “approved again” and want to know whether that is accurate as of today. The accurate answer is that the regulatory direction has shifted in a meaningful way, but the legal status has not yet changed.

What to know before considering it

TB-500 is available at Halftime Health under physician prescription, prepared patient-specifically by our licensed 503A compounding pharmacy partner. Vendors marketing TB-500 for human use through online or research-chemical channels without a valid prescription are not operating within the licensed clinical framework. The proposed reclassification to Category 1 — if finalized — would additionally open up 503B bulk production; Halftime Health will update this post when that change becomes effective.

The Halftime POV

The TB-500 reclassification process matters and is worth following. The distance between “proposed” and “effective” is also real. Both can be described accurately at once, and that is the position we take in our content.

Related reading:

• Category 1 vs Category 2 peptides: the access framework
• The February 2026 HHS announcement on peptide reclassification
• BPC-157 and the FDA: Category 2 status and what comes next

FAQ

Q: Is TB-500 legal in the United States? A: TB-500 is classified as Category 2, meaning it is not on the FDA’s approved list for 503B bulk outsourcing facilities. However, 503A compounding pharmacies — which prepare medications patient-specifically on demand under a valid physician prescription — operate under separate regulatory provisions. TB-500 is available through Halftime Health under physician prescription through our licensed 503A compounding pharmacy partner.

Q: What is the difference between 503A and 503B compounding? A: 503A pharmacies prepare individualized prescriptions on demand for a specific patient under physician supervision. 503B facilities are outsourcing facilities that manufacture larger batches without patient-specific prescriptions. The FDA’s Category 1/2 list primarily governs 503B bulk production. Halftime Health works with 503A pharmacies only — every prescription is prepared for the individual patient.

Q: Did the February 2026 HHS announcement change TB-500 status? A: The HHS announcement proposed returning TB-500 (and six other Category 2 peptides) to Category 1 for 503B bulk compounding purposes, but a proposal is not the same as an effective regulatory change. As of April 2026, the formal FDA Federal Register notice required to make the reclassification effective had not been published. Halftime Health will update this post if and when the formal status changes.

Disclaimer

TB-500 is available at Halftime Health under physician prescription, prepared patient-specifically by our licensed 503A compounding pharmacy partner. The FDA’s Category 2 classification restricts 503B bulk outsourcing production of TB-500; a February 2026 HHS announcement proposed returning it to Category 1 for bulk purposes, pending formal FDA Federal Register notice. This article is educational only and is not medical advice. Halftime Health only prescribes through licensed clinicians in states where our partner physicians are credentialed.

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Sources

• FDA. “Bulk Drug Substances That May Be Used in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act.” FDA.gov
• FDA. PCAC Meeting Materials, 2023. FDA.gov
• HHS Press Release. February 2026 peptide reclassification announcement. HHS.gov

This article discusses compounds that are currently under FDA Category 2 review (see our FDA categorization explainer). These compounds are not currently part of Halftime Health’s published protocol catalog. This article is provided for educational purposes only and does not constitute medical advice or an offer to sell.