Why the FDA banned 19 peptides from compounding in 2023

In 2023 the FDA placed 19 peptides on its Category 2 list. The legal effect is sharp: licensed compounding pharmacies in the United States cannot lawfully produce them. Among the 19 are BPC-157 and CJC-1295 — two of the most-discussed regenerative peptides in wellness communities.

The decision is often described in absolute terms (a "ban") and treated as proof of harm. The actual reasoning is more procedural, and worth understanding.

Category 2 in plain language

The FDA can authorize a compounding pharmacy to use a bulk drug substance only if it appears on a USP monograph (a third-party-certified recipe), is a component of an FDA-approved drug, or appears on the FDA’s positive "503A Bulks List." Substances under review go onto Categories 1 (likely safe to compound), 2 (significant safety risk), or 3 (more data needed). The 2023 decision moved 19 peptides — none of which has a USP monograph — into Category 2.

Category 2 is not a finding that a substance has caused harm. It is a finding that two specific risk dimensions cannot be ruled out:

• Immunogenicity. Synthetic peptides — especially modified ones — can trigger anti-drug antibodies. The reactions reported in the literature range from rashes to anaphylaxis. The FDA cannot screen for this from a sequence alone.
• Absence of human clinical data. Most peptides on the list have rodent efficacy signals and small pilot studies. None have the multi-arm Phase II/III data that would be required for an approved drug.

The political dimension

HHS Secretary Robert F. Kennedy Jr. has publicly framed the 2023 ruling as an "illegal war on peptides," arguing that the FDA should act on documented safety signals rather than a generalized lack of efficacy data. The legal critique is real even if the framing is sharp: Category 2 is functionally a ban that does not require proof of harm, only the absence of proof of safety.

Compounding-pharmacy associations have echoed the critique, particularly for peptides that have been used clinically in other jurisdictions. Both sides agree on the structural fact at the heart of the dispute: the gray market for these peptides is enormous, and the labels on online vials are often false. What they disagree on is whether the right response is regulatory closure or regulated channels with QC.

Category 2 does not say a peptide is dangerous. It says we cannot, with the data we have, say it is safe.

What changes in 2026–2027

The pivotal regulatory moment is not behind us — it is ahead. The FDA Pharmacy Compounding Advisory Committee (PCAC) is scheduled to revisit the 503A Bulks List in 2026–2027. That review will determine which of the 19 peptides stay in Category 2, which move to Category 1 or 3, and what data thresholds the agency wants before re-evaluating any of them.

For the regenerative-peptide market in particular, this review is likely to be the most consequential regulatory event in a decade. Stay close to it.