12 Peptides FDA Is Moving Off Category 2: Complete 2026 List

Category 2 historically denoted substances that FDA identified as raising significant safety risks sufficient to recommend against their use in 503A compounding. The April 15, 2026 Federal Register notice lists 12 peptides for advisory committee review. Reclassification would alter the status of these compounds within the pharmaceutical compounding framework. Research peptide supply channels operate separately under research-use-only labeling.

BPC-157 (Body Protection Compound-157) is a synthetic 15-amino acid peptide with the sequence GEPPPGKPADDAGLV, derived from a portion of human gastric juice protein. Its molecular weight is approximately 1419 Da. Preclinical literature focuses on gastrointestinal tissue models and tendon cell culture studies. Media attention has been elevated since 2023, contributing to its inclusion in the current review.

LL-37 is a 37-amino acid cathelicidin antimicrobial peptide, the active C-terminal fragment of human hCAP18. Sequence: LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES. Molecular weight approximately 4493 Da. Research focuses on host defense biology, biofilm interactions, and epithelial signaling. Published peer-reviewed literature is extensive in immunology and infectious disease journals.

DiHexa (N-hexanoic-Tyr-Ile-(6) aminohexanoic amide) is a hexapeptide derivative of angiotensin IV with extensive preclinical literature on hepatocyte growth factor receptor (c-Met) signaling in neuronal cell culture. It is structurally small, orally-available in rodent models, and has been studied in academic neuroscience programs. Molecular weight approximately 545 Da.

Delta Sleep-Inducing Peptide (DSIP) is a nonapeptide with sequence WAGGDASGE, molecular weight approximately 849 Da. First isolated in 1977 from rabbit cerebral venous blood, it has a lengthy academic literature in neurochemistry and sleep research. Its mechanism is incompletely characterized, which is one factor that has kept it in Category 2 during prior reviews.

Epitalon (also Epithalon) is a synthetic tetrapeptide Ala-Glu-Asp-Gly with molecular weight approximately 390 Da. Developed in the former Soviet Union by gerontology researcher Vladimir Khavinson, it has a Russian-language preclinical literature on pineal-derived peptide bioregulators. Western peer-reviewed literature is more limited, which has complicated prior FDA reviews.

GHK-Cu is the copper complex of the tripeptide glycyl-L-histidyl-L-lysine, molecular weight approximately 340 Da for the peptide and 402 Da for the copper complex. Topical GHK-Cu is widely documented in dermatological and wound healing literature. The current review specifically addresses injectable formulations of GHK-Cu, which raise additional safety questions distinct from topical preparations.

KPV is the C-terminal tripeptide Lys-Pro-Val of alpha-melanocyte-stimulating hormone. Molecular weight approximately 342 Da. Preclinical literature focuses on epithelial inflammatory signaling and intestinal cell models. Small size and oral bioavailability in rodent models make it a recurrent subject of compounding nominations.

PEG-MGF is a pegylated version of Mechano Growth Factor, the E-domain alternative splice variant of insulin-like growth factor-1. The pegylation increases plasma half-life in animal models. Molecular weight varies by PEG chain length, typically 5-10 kDa. Its status in prior reviews has reflected concerns about growth-factor-related signaling.

Melanotan II is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone. Sequence: Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2. Molecular weight approximately 1024 Da. Peer-reviewed literature on melanocortin receptor signaling is extensive. Media attention and non-research use have contributed to its regulatory profile.

MOTS-C is a 16-amino acid mitochondrial-derived peptide encoded within the 12S rRNA region of mitochondrial DNA. Sequence: MRWQEMGYIFYPRKLR. Molecular weight approximately 2174 Da. Academic literature emphasizes mitochondrial signaling and metabolic stress responses. It was first described in 2015 by Lee et al.

Semax is a synthetic heptapeptide Met-Glu-His-Phe-Pro-Gly-Pro, molecular weight approximately 814 Da. It is a synthetic analog of a fragment of adrenocorticotropic hormone (ACTH 4-10). Russian literature documents preclinical neurotrophic signaling studies. Its inclusion reflects the same evidentiary profile challenges as Epitalon.

TB-500 refers to a synthetic fragment (amino acids 17-23) of the full-length Thymosin Beta-4 protein. The full protein contains 43 amino acids with molecular weight approximately 4963 Da; the TB-500 fragment is approximately 890 Da. Preclinical literature examines actin-binding biology and cellular migration in culture models. Media attention over the past decade has kept it in ongoing review cycles.

If one or more of these peptides moves from Category 2 toward a posture that permits 503A compounding, the change would affect the pharmacy compounding channel only. Research peptide vendors supply substances labeled for in vitro and in vivo laboratory investigation, operate under research-use-only commercial terms, and are outside the compounding framework. Research institutions should maintain consistent procurement documentation regardless of the outcome.

• Pharmacy compounding: directly affected by Category 2 status changes
• Research peptide vendors: largely unaffected by compounding category decisions
• Research labeling, Certificates of Analysis, and purchase records remain the primary compliance artifacts for institutional procurement
• Advisory committee recommendations are not final agency actions; formal rulemaking would follow

This article is informational and references official U.S. government sources and peer-reviewed scientific literature.