Back to the journal
Peptides
6 min read
Updated Oct 29, 2026.
Status, both: HHS won't act on licensed compounders, for now. Still not approved. On Oct 28, 2026 HHS filed an interim policy saying it won't take enforcement action against state-licensed pharmacies, federal facilities or licensed physicians compounding BPC-157 acetate or TB-500 acetate while the 503A list goes through rulemaking [13]. Both are covered. Off Category 2 since Apr 2026, each recommended 8 to 6 by FDA's advisory panel in Jul 2026, neither on the 503A bulks list, neither approved by FDA for any use. Sources: HHS policy filed Oct 28, 2026, publishing in the Federal Register Oct 30, 2026 [13]; FDA (Category 2 page as of Apr 22, 2026; 503A list as of May 14, 2026; panel votes Jul 23, 2026). As of Oct 29, 2026.
Part of The Sommar Peptide Guide. BPC-157 and TB-500 often get named together, and FDA's advisory panel voted on both the same day. Their regulatory status matches. Their evidence does not.
The short answer
Same vote, same HHS policy, different evidence. FDA found 5 small, short human studies of BPC-157 and none of TB-500 [3][4]. Both are in HHS's Oct 28, 2026 interim compounding policy. Neither is approved by FDA for any use, and neither is on the list pharmacies need to compound it [1][2][13].
Side by side
BPC-157 | TB-500 | |
|---|---|---|
What it is | 15 amino acids, a fragment of a protein first isolated from human gastric juice [3] | 7 amino acids, a fragment of thymosin beta-4, a tissue-repair protein [4] |
Nominated for | Ulcerative colitis [4] | Wound healing, type not stated [4] |
Nominated forms | Oral capsules, injection under the skin, nasal spray, rectal suppository, skin cream [4] | Injection under the skin or into muscle [4] |
Human studies found by FDA | 5, short and small [3] | None [4] |
Animal evidence | Many rat studies of tissue healing [5] | No published animal wound studies; lab and metabolism work only [4] |
Animal toxicity | Clotting and liver signals in 28-day rat and dog studies [3] | No toxicity studies found [4] |
Tumor question | Theoretical concern, not established in humans [6] | Concern about tumor progression raised by FDA reviewers and panel members [6] |
FDA staff recommendation | Leave off the 503A list [4] | Leave off the 503A list [4] |
Panel vote, Jul 23, 2026 | 8 to 6, 1 abstention [6][7] | 8 to 6, 1 abstention [6][7] |
HHS interim policy, Oct 28, 2026 | Covered: acetate, under the skin, into muscle, oral or topical [13] | Covered: acetate, under the skin or into muscle [13] |
WADA | Prohibited, S0 [8] | Prohibited, S2.3 [8] |
Where they match on status
Both came off FDA's Category 2 safety-risk list in Apr 2026, among 12 peptides whose nominators withdrew them [1][9]. Coming off that list put neither on the 503A bulks list. As of FDA's list dated May 14, 2026, neither is on it [2].
On Jul 23, 2026, FDA staff recommended against both. FDA's Pharmacy Compounding Advisory Committee voted 8 to 6, with 1 abstention, to recommend each anyway [6][7]. The votes are advice. FDA is not bound by them, and changing the list takes notice-and-comment rulemaking [6].
Both are in the HHS policy. On Oct 28, 2026, HHS filed the interim peptide policy it sent for review on Oct 14 [10][13]. AP had reported it would include BPC-157 [11]. The filed policy covers BPC-157 acetate and TB-500 acetate, among six peptides. HHS says it won't take enforcement action against state-licensed pharmacies, federal facilities or licensed physicians that compound them under its conditions [13][14]. It is interim and not binding, and it approves neither. Read the full breakdown in HHS's Oct 28 peptide policy. The FDA Peptide Tracker logs each step.
The gap between "off Category 2" and legal is covered in Are Peptides Legal?.
Where they split on evidence
BPC-157 has a little human data. FDA's briefing lists 5 human studies: two rectal enema studies (24 healthy adults; people with ulcerative colitis, 53 randomized, reported only as a meeting abstract), knee injections in 17 people, a bladder instillation in 12 and an IV infusion in 2 [3]. FDA called them short, small and likely exploratory in dose [3]. A 2025 systematic review found 35 preclinical studies and 1 human study in its scope, and said BPC-157's safety in people "remains unknown" [5].
TB-500 has none. "No studies were found in the literature in which TB-500 was administered to humans," FDA said [4]. In one lab study it did not promote wound closure in cultured cells [4]. The human trials often quoted for TB-500 used full-length thymosin beta-4, mostly as eye drops and for skin ulcers [12]. That is the 43-amino-acid protein. TB-500 is the 7-amino-acid fragment [12].
Neither has a combination study. Nobody has tested the two together in people. FDA found no human study of TB-500 at all [4].
Where they split on risks
Neither has enough human data for a real side effect list. The flags differ.
BPC-157 [3][6]:
Clotting times shifted and liver markers rose in 28-day rat and dog studies.
FDA said it "may pose a significant risk for immunogenicity," mainly by injection or nasal spray.
A theoretical tumor concern, "not established in humans."
No carcinogenicity studies.
TB-500 [4][6]:
No toxicity studies of any kind.
Immune reaction risk for injected peptides, raised by clumping and impurities.
A tumor-progression concern raised by FDA reviewers and some panel members, with no studies of TB-500 to answer it.
Poorly characterized, per FDA.
Both. Impurities and aggregation, and a WADA ban [3][4][8]. Both are widely sold online as "research use only," which is the seller saying the product is not for people [7].
More on each: What Is BPC-157?, What Is TB-500?. Same shelf: KPV.
FAQ
What is the difference between BPC-157 and TB-500? Different molecules from different proteins. BPC-157 is 15 amino acids from a gastric juice protein. TB-500 is a 7-amino-acid piece of thymosin beta-4 [3][4]. BPC-157 has 5 small human studies per FDA. TB-500 has none [3][4].
Is BPC-157 or TB-500 better? Nobody can say. They have never been compared in people, and TB-500 has never been studied in people at all [4].
Are BPC-157 and TB-500 legal? Both came off Category 2 in Apr 2026 and both got an 8 to 6 panel vote in Jul 2026. Neither is on the 503A bulks list or approved by FDA for any use [1][2][6]. On Oct 28, 2026 HHS filed an interim policy saying it won't take action against licensed compounders of either one, in acetate form, under its conditions. HHS can revise it [13]. This is not legal advice.
Is it safe to take BPC-157 and TB-500 together? There is no human data on the combination. FDA lists separate safety concerns for each [3][4].
Are BPC-157 and TB-500 banned in sports? Yes. WADA lists BPC-157 under S0 and TB-500 under S2.3 [8].
Sources
FDA. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (content current as of Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
FDA. Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act (content current as of May 14, 2026). https://www.fda.gov/drugs/human-drug-compounding/bulk-drug-substances-used-compounding-under-section-503a-fdc-act
FDA. Pharmacy Compounding Advisory Committee briefing document, BPC-157 (Jul 2026). https://www.fda.gov/media/193343/download
FDA. Presentation to the Pharmacy Compounding Advisory Committee (Jul 23, 2026). https://www.fda.gov/media/193773/download
Vasireddi N, et al. Emerging Use of BPC-157 in Orthopaedic Sports Medicine: A Systematic Review. HSS J. 2025;21(4):485-495. https://pmc.ncbi.nlm.nih.gov/articles/PMC12313605/
Bass Berry. FDA Advisory Committee Recommends Six Peptides for Compounding (Jul 31, 2026). https://bassberry.com/news/fda-advisory-committee-recommends-six-peptides-for-compounding-what-the-evaluation-criteria-tell-us-about-the-road-ahead/
AJMC. FDA Panel Backs 6 Peptides for Compounding (Jul 31, 2026). https://www.ajmc.com/view/fda-panel-backs-6-peptides-for-compounding
World Anti-Doping Agency. The 2026 Prohibited List. https://www.wada-ama.org/en/prohibited-list
Frier Levitt. FDA Peptides "Do Not Compound" List Update (Apr 16, 2026). https://www.frierlevitt.com/articles/fda-peptides-do-not-compound-list-update-2026/
Holland & Knight. Peptides at a Crossroads: What Wellness Providers Need to Know (Oct 16, 2026). https://www.hklaw.com/en/insights/publications/2026/10/peptides-at-a-crossroads-what-wellness-providers-need-to-know
AP via ABC News. Trump administration advances plan for peptide drugs (Oct 15, 2026). https://abcnews.com/Business/wireStory/trump-administration-advances-plan-peptide-drugs-favored-rfk-137299803
McGuire F, Hughes E, Maak T, Cushman DM. Thymosin Beta-4 and TB-500 in Tissue Healing, Regeneration, and Musculoskeletal Repair: A Scoping Review. Appl Sci. 2026;16(12):6202. Preprint: https://www.preprints.org/manuscript/202605.1124/v1
HHS. Enforcement Discretion Policy Regarding 503A Compounding Using Certain Peptide Bulk Drug Substances. Docket HHS-OASH-2026-0496, FR Doc 2026-22192 (filed for public inspection Oct 28, 2026; scheduled to publish in the Federal Register Oct 30, 2026). https://public-inspection.federalregister.gov/2026-22192.pdf
Hyman, Phelps and McNamara, FDA Law Blog. The PEPTIDE-L Wave Reaches HHS: Enforcement Discretion … Not the Finish Line (Oct 28, 2026). https://www.thefdalawblog.com/2026/10/the-peptide-l-wave-reaches-hhs-enforcement-discretion-not-the-finish-line/
Sommar Club does not prescribe or sell BPC-157 or TB-500. This page is for education only. It is not medical or legal advice. FDA statuses change; check the as-of dates and the FDA Peptide Tracker.
