KPV, TB-500, and MOTS-c Have No Human Trial Data: What FDA's Own Reviewers Wrote

What FDA Staff Posted Before the July 2026 PCAC Meeting

The 503A bulks list is the list of bulk drug substances that compounding pharmacies operating under section 503A of the Federal Food, Drug, and Cosmetic Act may legally use in compounded preparations. Getting a substance onto that list is a formal process, and PCAC is the advisory committee that reviews nominations and votes on recommendations.

Before each meeting, FDA career staff publish briefing documents that walk through the evidence for each nominated substance. The framework has four parts: how well the substance is characterized chemically, what safety data exists, what evidence of effectiveness exists for the specific nominated use and route, and what history of use in compounding can be documented. Ahead of the July 23-24, 2026 meeting, staff posted those packages for all seven nominated peptides, which were BPC-157, KPV, TB-500, MOTS-c, epitalon, semax, and emideltide (also known as DSIP). Staff recommended against adding every one of them.

That recommendation drew attention for a political reason as well as a scientific one. Reporting on June 30, 2026 from NPR and The Washington Post framed the staff reviews as FDA career scientists publicly contradicting HHS Secretary Robert F. Kennedy Jr.'s push to widen access to compounded peptides. Separate reporting also raised questions about industry ties among members of the advisory panel itself. For anyone tracking a protocol, though, the more useful part is not the politics. It is that the reviews put a specific, citable federal finding behind a question the peptide market usually answers with marketing copy.

The Three Peptides Where Reviewers Found No Human Studies

Across the seven reviews, three peptides stood apart. For KPV, TB-500, and MOTS-c, FDA staff reported finding no human clinical trial data at all for the nominated uses. Not weak data, not mixed data, not underpowered data. None.

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This is the distinction that most peptide content blurs. Preclinical data is not human trial data. A compound can have a large and genuinely interesting literature in rodents and in cultured human cells while having zero controlled trials in living people. KPV is a clear example: the published anti-inflammatory work exists, it is real, and it is preclinical. Reviewers looking for human studies did not find them.

TB-500 is the starkest case in the set. Reviewers reported that the nomination itself included no clinical data, that they could find no published literature in which TB-500 had been administered to patients for any condition, and that one cited in vitro experiment did not show wound healing in fibroblast cultures. They also flagged that subcutaneous and intramuscular peptide injection carries immunogenicity risk from aggregation and impurities, and that no data existed showing TB-500 avoids that risk.

The same logic applies to MOTS-c, which was nominated for injectable metabolic uses. MOTS-c is a peptide encoded in mitochondrial DNA, and the mechanistic literature around mitochondrial signaling is active. That is not the same as a randomized trial in humans, and FDA staff reported that no such human data was found.

BPC-157 Shows What "Some Human Data" Actually Looks Like

BPC-157 is the most tracked compound in this category, and its review is worth reading closely because it shows what "there are human studies" turns into once you inspect it.

Reviewers identified a single item: a conference meeting abstract reporting a study in 46 people, in which the peptide was given as an enema rather than by injection. The nominated use was ulcerative colitis. That distinction matters more than it looks. A meeting abstract is a short conference submission, not a peer-reviewed trial report, and it sits well below a published randomized controlled trial on any evidence hierarchy.

On that basis, FDA staff wrote that there is a lack of evidence to support the effectiveness of BPC-157 for the nominated use, that the substance is not well characterized, and that quality standards cannot be established for it. In the meeting itself, an FDA representative put the characterization problem bluntly, asking what BPC-157 actually is and noting that quality standards cannot be set without better answers. Reviewers also noted that adverse event reports involving BPC-157 exist in FAERS, the FDA Adverse Event Reporting System, including reports tied to compounded injectable product, though causality in those reports was confounded.

Three separate points are stacked there, and each one matters on its own. Effectiveness for the nominated use was not established. Characterization, meaning knowing exactly what the substance is at a chemical level, was inadequate. And quality standards, meaning the specifications a pharmacy would need to reliably make the same thing twice, could not be set.

Note also the route mismatch. The one human report reviewers found used an enema. The community protocol conversation around BPC-157 is overwhelmingly about injection. Evidence for one route is not automatically evidence for another, and FDA reviews evaluate the specific nominated route for exactly that reason.

### The findings that repeated across every review

Read as a set, the seven reviews share a small number of recurring problems rather than one isolated complaint.

Inconsistent naming deserves a moment. If the same compound is sold and described under several names and specifications, and the acetate salt, the free base, and various fragments are discussed interchangeably, then "the evidence for X" becomes an unstable claim. Reviewers named that problem directly, and it is the same problem a person faces when trying to compare a study to a vial.

The Vote Went the Other Way. The Evidence Did Not Change.

On July 23 and 24, 2026, PCAC voted to recommend six of the seven peptides for the 503A bulks list, against the staff position. As reported, BPC-157, KPV, and TB-500 each passed 8 to 6 with one abstention, and MOTS-c passed 7 to 5 with two abstentions. Epitalon and semax also passed. Emideltide was the single rejection, failing on a 6 to 7 vote with one abstention.

Committee members who voted no said so on evidentiary grounds. PCAC member Dr. Elizabeth Rebello, an executive director in anesthesiology, critical care, and pain medicine at the University of Texas MD Anderson Cancer Center, flagged the lack of efficacy data during deliberations and was reported as saying the committee risked "responding to a market-induced demand rather than a decision based in solid science." Member Todd Durham raised a different concern, that adding peptides to the list could mislead consumers about their FDA approval status. Members who voted yes largely framed it as harm reduction, reasoning that refusing the compounding pathway pushes people toward an unregulated gray market.

Two procedural facts matter for anyone reading headlines about this. First, PCAC recommendations are advisory and not binding on the FDA. Second, nothing changes for compounding until FDA completes formal notice-and-comment rulemaking. That pathway runs from an FDA decision to a proposed rule, then a public comment period typically lasting 60 to 90 days, then a final rule, a sequence that legal analysts estimate commonly takes 12 to 24 months. A favorable vote is not an approval, not an indication, and not a statement that a compound works. It is a recommendation about whether pharmacies may compound a bulk substance under a prescription, and it sits near the beginning of that process, not the end.

### Corrections to three of our earlier posts

The federal record also forces us to correct our own coverage, which is worth doing in the open.

Our earlier preview of this meeting, [PCAC July 23, 2026 Vote: 4 Peptides on the Docket](/blog/pcac-july-2026-peptide-vote), was written in April 2026 and described a four-peptide docket. The final docket was seven, adding epitalon, semax, and emideltide alongside BPC-157, KPV, TB-500, and MOTS-c. We are noting that here rather than leaving the earlier framing to stand on its own.

Our post [TB-500 Cardiac Recovery: What the 2026 Human Trial Data Shows](/blog/tb-500-cardiac-recovery-2026) presents human trial findings for thymosin beta-4 in cardiac recovery, including effect sizes and dose ranges. That framing does not match what FDA staff reported when reviewing TB-500 for the nominated wound-healing use, which was that they could find no literature in which TB-500 had been administered to patients for any condition. Part of the gap is a naming problem of exactly the kind reviewers criticized: thymosin beta-4 is the full-length peptide, while TB-500 as sold and as nominated is commonly described as a shorter fragment, and evidence about one is routinely presented as evidence about the other. We have not verified that post's specific trial figures against a primary source. Treat those numbers as unverified pending a rewrite, and treat the FDA staff finding as the current defensible statement about TB-500's human evidence base.

Similarly, our [MOTS-c protocol guide](/blog/mots-c-protocol-guide) describes metabolic effects associated with MOTS-c in language that reads as human outcomes. Those descriptions reflect preclinical and mechanistic work, not human trial results, and the FDA staff review found no human clinical trial data for the nominated injectable metabolic use. We are flagging the distinction rather than letting the earlier phrasing imply more than the evidence supports.

WADA Prohibited Status for MOTS-c and TB-500

The FDA reviews also noted World Anti-Doping Agency prohibited status for MOTS-c and TB-500. This is a completely separate regulatory system from compounding, and it is the one that carries immediate consequences for anyone in a tested sport.

On the 2026 Prohibited List, TB-500 falls under section S2 as a growth factor, in the entry covering thymosin beta-4 and its derivatives, and MOTS-c is named under section S4 among metabolic modulators. Competitive eligibility is governed by the WADA Code and that annual list, not by the 503A bulks list. A compound can move toward legal compounding availability in the United States and remain fully prohibited for a tested athlete at the same time. Enforcement in that system is also not limited to positive tests, since use, attempted use, and possession can each be established through non-analytical evidence. Our reporting on the [2026 WADA Prohibited List and peptides](/blog/peptides-wada-drug-testing-2026) covers how that works in more detail. Any athlete should confirm their own status with their sport's anti-doping authority, which is the only definitive source.

What People Track Around These Compounds

If you are working with a clinician on anything in this category, the value of a tracking record goes up precisely when the evidence base is thin. When published human outcome data does not exist, your own longitudinal labs are the only data specific to you, and a clean record is what makes a provider conversation productive rather than speculative. None of the following is a recommendation to test or to run any protocol. It is a description of what people commonly log, so you can organize your own record and discuss it with a qualified professional.

Consistency is what makes any of this usable. Same fasting conditions, same lab where possible, dates logged, and a trend read over months rather than a reaction to any single value. [Keep your labs, protocols, and dates in one organized record with MyProtocolStack.](/auth/login?mode=signup)

For coaches, trainers, and anyone advising clients inside a non-clinical scope, the FDA staff finding is unusually useful because of what it is and is not. Saying "federal reviewers found no human clinical trial data for KPV, TB-500, or MOTS-c for the nominated uses" is a statement about the evidence base. It is not a claim that a compound works, does not work, is safe, or is unsafe. That keeps the conversation inside scope while still setting an honest expectation, and it is sourced to a government document rather than to an opinion. A client asking whether a compound will produce a result is asking a clinical question for a licensed clinician. A client asking what is actually known is asking an evidence question, and that one has a documented answer today. If you work with tested athletes, the WADA prohibited status for MOTS-c and TB-500 is the second thing to raise, because that consequence is immediate and does not wait on any rulemaking.

The regulatory picture will keep moving. Rulemaking takes time, comment periods open and close, and the staff position and the committee vote currently point in opposite directions. What does not change with the news cycle is the record you keep. Bring consistent, well-organized data to the people qualified to interpret it, and let the evidence base be described accurately in the meantime.

Frequently Asked Questions

Is there any human trial data for KPV, TB-500, or MOTS-c?

According to FDA staff briefing documents posted ahead of the July 23-24, 2026 PCAC meeting, no. Reviewers reported finding no human clinical trial data at all for KPV, TB-500, or MOTS-c supporting the uses they were nominated for. For TB-500, staff reported they could find no published literature in which the peptide had been administered to patients for any condition. The published record behind these three is preclinical, meaning animal models and cell studies, which is not the same as evidence from controlled trials in living people.

What did FDA staff conclude about BPC-157?

FDA staff wrote that there is a lack of evidence to support effectiveness for the nominated use, ulcerative colitis, that the substance is not well characterized, and that quality standards cannot be established for it. The only human data reviewers identified was a conference meeting abstract describing a study in 46 people, administered as an enema rather than by injection. A meeting abstract is not a peer-reviewed trial report. Adverse event reports involving BPC-157 also exist in FAERS, the FDA Adverse Event Reporting System.

If FDA staff recommended against all seven peptides, why did the committee vote yes on six?

PCAC voted on July 23 and 24, 2026 to recommend six of the seven despite the staff position, on narrow margins. As reported, BPC-157, KPV, and TB-500 each passed 8 to 6 with one abstention, and MOTS-c passed 7 to 5 with two abstentions. Epitalon and semax also passed, and emideltide was rejected 6 to 7 with one abstention. Members voting no cited the lack of efficacy data. Members voting yes largely framed it as harm reduction relative to an unregulated gray market. The votes are advisory and not binding.

Does the PCAC vote mean these peptides are now approved or legal to compound?

No. PCAC recommendations are advisory only and are not binding on the FDA, and nothing changes for compounding pharmacies until FDA completes formal notice-and-comment rulemaking, which runs from a proposed rule through a public comment period to a final rule and commonly takes 12 to 24 months. A favorable vote is not an FDA approval, does not create an approved indication, and does not say a compound is effective. It is a recommendation about whether a bulk substance may be used in compounded preparations under prescription.

Are MOTS-c and TB-500 banned for tested athletes?

The FDA reviews noted World Anti-Doping Agency prohibited status for both MOTS-c and TB-500. On the 2026 Prohibited List, TB-500 sits under section S2 as a growth factor and MOTS-c is named under section S4. Anti-doping status is a separate system from compounding rules, so a compound can move toward legal compounding availability and still be fully prohibited in tested sport. Enforcement also includes non-analytical violations such as use, attempted use, and possession, so detectability on a test is not the relevant question. Confirm your own status with your sport's anti-doping authority.

Sources

1. U.S. Food and Drug Administration, 2026 Meeting Materials, Pharmacy Compounding Advisory Committee (briefing packages for the July 23-24, 2026 meeting). https://www.fda.gov/advisory-committees/pharmacy-compounding-advisory-committee/2026-meeting-materials-pharmacy-compounding-advisory-committee

2. Orrick, "FDA Peptide Compounding Vote: What to Watch at the July PCAC Meeting," July 2026. https://www.orrick.com/en/Insights/2026/07/FDA-Peptide-Compounding-Vote-What-to-Watch-at-the-July-PCAC-Meeting

3. NPR, "FDA scientists flag concerns with peptides, the trendy molecules RFK Jr. supports," June 30, 2026. https://www.npr.org/2026/06/30/nx-s1-5876301/peptides-fda-panel-compounding-rfk

4. The Washington Post, "RFK Jr.'s plan to boost peptide access just got more complicated," June 30, 2026. https://www.washingtonpost.com/health/2026/06/30/fda-staff-recommendation-undercuts-rfk-jrs-push-expand-peptides/

5. TIME, "An FDA Committee Just Voted in Favor of Peptides, Despite the Agency's Opposition," July 23, 2026. https://time.com/article/2026/07/23/fda-committee-peptides/

6. Regulatory Affairs Professionals Society (RAPS), "FDA advisory committee backs two controversial peptides," July 2026. https://www.raps.org/resource/fda-advisory-committee-backs-two-controversial-peptides.html

7. Regulatory Affairs Professionals Society (RAPS), "FDA advisory committee backs two more peptides, rejects one for compounding list," July 24, 2026. https://www.raps.org/resource/fda-advisory-committee-backs-two-more-peptides-rejects-one-for-compounding-list.html

8. Mintz, "FDA's Advisory Committee Votes on Peptides: What It Does and Doesn't Do," July 29, 2026. https://www.mintz.com/insights-center/viewpoints/2146/2026-07-29-fdas-advisory-committee-votes-peptides-what-it-does-and

*MyProtocolStack is a tracking and education tool, not medical advice, diagnosis, or treatment, and you should always consult a qualified healthcare professional before making any changes to your health protocol.*