Research data ยท Pain and nociception

Formalin test

From 2021 to 2025, 545 animal research papers mentioned the formalin test in their title or abstract, ranking it 23rd of the 90 tests we track.

That is 31% fewer than the 790 papers of 2011 to 2015. Papers that mention any of the 90 tests rose 22% over the same span.

545 animal research papers from 2021 to 2025 mentioned the test
31% fewer papers than in 2011 to 2015
23rd of the 90 tests by papers from 2021 to 2025
65% of these papers used mice and 42% used rats

Papers by year

Animal research papers that mention the formalin test, by year, 2001 to 2026

The 2026 bar counts papers added to PubMed by November 8, 2026.

  • Papers in a full year
  • 2026 so far
Show the counts for each year
Papers by year
YearPapers
2001103
200275
2003107
2004110
2005124
2006122
2007116
2008115
2009132
2010161
2011159
2012154
2013164
2014169
2015144
2016139
2017145
2018117
2019120
2020134
2021140
2022127
202397
202497
202584
2026 (part year)79

Rats led every year from 2001 to 2010, and mice every year since 2011.

Papers that mention the formalin test in mice and in rats, by year, 2001 to 2025

  • Mouse
  • Rat
Show the counts for each year and species
Papers by year, mice and rats
YearMouseRat
20014567
20022951
20034379
20044181
20054687
20066377
20075973
20086074
20096878
201092106
201110089
20129287
201311083
201410297
20159465
20169855
20179863
20187255
20197665
20208370
20219554
20227456
20236039
20246341
20256140

Which species the papers used

Each bar is a share of the 545 papers from 2021 to 2025. A paper can use more than one species, so the shares can add to more than 100%.

Species

Mouse
353 papers 65%
Rat
230 papers 42%
Other animals
17 papers 3%
Zebrafish
4 papers 1%

โ€œOther animalsโ€ counts papers that use none of the other species in this chart.

Strains and genetic lines

Strain names come from the MeSH terms PubMed adds when it indexes a paper. PubMed has indexed 436 of the 545 papers, so each bar is a share of those 436.

Wistar rats
67 papers 15%
Sprague-Dawley rats
61 papers 14%
C57BL mice
30 papers 7%
ICR mice
11 papers 3%
BALB/c mice
10 papers 2%
Transgenic mice
5 papers 1%
Knockout mice
2 papers under 1%
Wistar Kyoto rats
1 paper under 1%

A paper indexed under two of these headings, such as knockout mice and a strain, counts under both.

Disease models these papers study

Each bar counts the papers from 2021 to 2025 that mention the formalin test and study that disease model, with its share of the 545 papers. The model comes from a paper's MeSH terms. For a paper PubMed has not indexed, it comes from PubTator 3, NCBI's text-mining service, when that service finds the disease in the title or abstract. A paper can count under more than one model.

Papers from 2021 to 2025 by disease model

Tests mentioned alongside the formalin test

Each bar counts the papers from 2021 to 2025 that mention both tests, with its share of the 545 papers that mention the formalin test.

Papers from 2021 to 2025 that mention both tests

127 papers 23%
108 papers 20%
65 papers 12%
38 papers 7%
34 papers 6%
26 papers 5%
18 papers 3%

The most cited papers from 2021 to 2025

These papers from 2021 to 2025 mention the formalin test and have the most citations, as counted by NIH's iCite on November 5, 2026. We show four of the five most cited papers and leave out one because of words in its title.

  1. Neuronal basis for pain-like and anxiety-like behaviors in the central nucleus of the amygdala.

    Pain, 2022. 47 citations.

  2. Investigation of the anti-inflammatory effects of stigmasterol in mice: insight into its mechanism of action.

    Behav Pharmacol, 2021. 44 citations.

  3. Antagonism of CGRP Receptor: Central and Peripheral Mechanisms and Mediators in an Animal Model of Chronic Migraine.

    Cells, 2022. 42 citations.

  4. Characterization of the peripheral FAAH inhibitor, URB937, in animal models of acute and chronic migraine.

    Neurobiol Dis, 2021. 41 citations.

How we counted

A count is the number of animal research papers whose title or abstract mentions one of the test's search terms. It is not a count of experiments, labs or animals.

A paper that mentions the formalin test only in its methods is missed, so the count runs low. The count includes 2 reviews. For 109 of the 545 papers, PubMed's indexing gave no species, so the species came from PubTator 3 finding one in the title or abstract.

The test's search terms are in the test list download. The full method, with each source and its terms of use, is on our main page, Behavioral tests in published research.

More pain and nociception tests

These pain and nociception tests also have a page, with their papers from 2021 to 2025. Each test with 30 or more papers gets one.

How to cite

APA

ConductScience. (2026, November 10). Formalin test in published research [Data set]. https://conductscience.com/data/behavioral-tests/formalin-test

BibTeX

@misc{conductscience_formalin_test_2026,
  author = {{ConductScience}},
  title = {Formalin test in published research},
  year = {2026},
  month = nov,
  url = {https://conductscience.com/data/behavioral-tests/formalin-test},
  note = {Data set, released November 10, 2026},
}