Peptide Sentinel

Data-led reporting on the peptide research record

Investigation

5 flagged titles in 902

A screen for negative findings across every record title this corpus holds returned 5 candidates out of 902. That measures the screen as much as the literature, and the first version of the screen was wrong about roughly half of what it found.

Published 13 October 2026Subject: 902 record titles across 77 compoundsCounted 13 October 2026

  1. 5 of 902 titles were flagged as reporting an absent, failed or negative effect: 0.55%, on 5 of 77 compounds.
  2. 72 compounds returned nothing. The honest reading of that is "nothing in the titles", not "nothing negative exists".
  3. Only titles were read. A null result reported inside a paper whose title is neutral is invisible to this method, and most titles are neutral.
  4. The first version of the screen was roughly half false positives, because "heart failure" and "kidney failure" name conditions rather than failed studies. Three corrections followed; the current marker list is printed in full below.
  5. A further 1 record was separated out rather than counted as negative: a non-effect on a pharmacokinetic or tolerability measure is usually a reassuring result.

What the screen is

Every record this corpus carries has a title. A short list of negation markers was matched against all 902 of them. A match makes the record a candidate: a title that reads as reporting an absent, failed or negative effect. It is not a finding about the compound, and it is not a judgement on the study.

Across 77 compounds, the screen returned 5 candidates, on 5 compounds. 72 compounds returned nothing. That is 0.55% of titles screened.

The markers the screen matches, and how many titles each one caught
MarkerWhat it matchesTitles caught
no effecta title stating no effect, with or without a qualifier such as apparent or significant1
does not actdoes, did or do not, followed within two words by an effect verb4
failed tothe phrase failed to, which cannot be a condition name0
without effectwithout effect, benefit or improvement0
negative resultnegative result, finding, trial or study0
no benefitno benefit, improvement, difference, association or change0
ineffectiveineffective, or lack of effect or efficacy0
not associatednot associated, superior or effective0
unaffectedunchanged or unaffected0
retractionretracted or retraction0

Two of the ten markers caught anything. The other eight returned nothing across all 902 titles, which is itself a result about the screen.

The five

These are the five candidates in full. The titles are quoted exactly as the records carry them. Read them as what the screen found, not as what the literature says: a title is a sentence an author wrote about one experiment, and the piece makes no claim about what any of these papers concluded or how they were received.

Every discordance candidate in the corpus
Named in the titleMarkerYearRecord
Capromorelindoes not act2025The 4 prokinetic drugs metoclopramide, cisapride, pyridostigmine, and capromorelin do not increase fecal output or food intake in healthy New Zealand rabbits (Oryctolagus cuniculus)
PMID 40179972
Mechano growth factorno effect2014Mechano-growth factor peptide, the COOH terminus of unprocessed insulin-like growth factor 1, has no apparent effect on myoblasts or primary muscle stem cells
PMID 24253050
Noopeptdoes not act2019Drug with Neuroprotective Properties Noopept Does Not Stimulate Cell Proliferation
PMID 30788746
Thymosin beta 4does not act2012Thymosin beta 4 treatment after myocardial infarction does not reprogram epicardial cells into cardiomyocytes
PMID 21907210
Vasoactive intestinal peptidedoes not act2008Vasoactive intestinal peptide causes marked cephalic vasodilation, but does not induce migraine
PMID 18254893

Each row is one bibliographic record retrieved by the compound's own literature query. No full text was read.

The first pass was wrong about roughly half of what it found

This matters more than the count. The first version of the screen used a bare match on failure and a bare match on does not. It was roughly half false positives, and the reason is specific: in clinical titles "failure" almost always names a condition rather than a failed study.

It flagged a trial of semaglutide in patients with obesity-related heart failure, and a trial comparing early vasopressin with norepinephrine on kidney failure. Neither is a negative result. Both are titles containing the word. A reader shown that output would have learned, correctly, to ignore the whole signal.

Three corrections followed, and they are the reason the current list looks the way it does in the table above. The marker failure was removed entirely, leaving only failed to, which cannot name a condition. A bare does not was required to be followed within two words by an effect verb. And a non-effect on a pharmacokinetic or safety measure was moved out of the negative category altogether.

The record that was moved out

The screen moved 1 record out of the negative category: it matched a marker in a pharmacokinetic and tolerability context, so it is reported separately rather than as a negative finding.

Non-effect on a pharmacokinetic or safety measure, counted separately
Named in the titleYearRecord
Cagrilintide2026Renal or Hepatic Impairment Does Not Affect Pharmacokinetics, Safety, or Tolerability of Subcutaneous Cagrilintide
PMID 42228334

A title reporting that something does not alter exposure or tolerability is usually a reassuring result. Counting it as discordance would invert its meaning, so the dataset carries it in a separate category column.

What a rate of this size can and cannot mean

0.55% of titles is a measurement of the screen at least as much as of the literature. Three things would each produce it on their own, and this analysis cannot tell them apart.

A null result can be reported in a paper whose title is neutral, which is the normal case: most titles name the subject and the model, not the direction of the result. A null result can go unpublished, which is a well-documented pattern in the research literature generally and is not something a title screen can observe. Or the records here can simply be the most-cited work under each name, which is what the retrieval was sorted by, and heavily cited papers are not a random sample of outcomes.

So the defensible statement is narrow, and it is the one this publication makes: of the 902 titles this corpus carries, 5 are phrased as reporting an absent or negative effect. Anything stronger would need the full texts, and this publication does not read them.

What this cannot show