Research data · 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. Between the same two periods, all the animal research papers that mention any of the 90 tests we count rose 22%.
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
| Year | Papers |
|---|---|
| 2001 | 103 |
| 2002 | 75 |
| 2003 | 107 |
| 2004 | 110 |
| 2005 | 124 |
| 2006 | 122 |
| 2007 | 116 |
| 2008 | 115 |
| 2009 | 132 |
| 2010 | 161 |
| 2011 | 159 |
| 2012 | 154 |
| 2013 | 164 |
| 2014 | 169 |
| 2015 | 144 |
| 2016 | 139 |
| 2017 | 145 |
| 2018 | 117 |
| 2019 | 120 |
| 2020 | 134 |
| 2021 | 140 |
| 2022 | 127 |
| 2023 | 97 |
| 2024 | 97 |
| 2025 | 84 |
| 2026 (part year) | 79 |
Rats led every year from 2001 to 2010, and mice every year since 2011.
Papers that mention the formalin test, by species, 2001 to 2025
- Mouse
- Rat
Show the counts for each year and species
| Year | Mouse | Rat |
|---|---|---|
| 2001 | 45 | 67 |
| 2002 | 29 | 51 |
| 2003 | 43 | 79 |
| 2004 | 41 | 81 |
| 2005 | 46 | 87 |
| 2006 | 63 | 77 |
| 2007 | 59 | 73 |
| 2008 | 60 | 74 |
| 2009 | 68 | 78 |
| 2010 | 92 | 106 |
| 2011 | 100 | 89 |
| 2012 | 92 | 87 |
| 2013 | 110 | 83 |
| 2014 | 102 | 97 |
| 2015 | 94 | 65 |
| 2016 | 98 | 55 |
| 2017 | 98 | 63 |
| 2018 | 72 | 55 |
| 2019 | 76 | 65 |
| 2020 | 83 | 70 |
| 2021 | 95 | 54 |
| 2022 | 74 | 56 |
| 2023 | 60 | 39 |
| 2024 | 63 | 41 |
| 2025 | 61 | 40 |
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
“Other animals” counts papers that use none of the species this chart names.
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.
A paper indexed under two of these headings, such as knockout mice and a strain, counts under both.
Disease models in papers that mention the formalin test
Each bar is one disease model, with how many of the 545 papers from 2021 to 2025 that mention the formalin test use it, and what share that is. The model comes from the paper's MeSH terms, the subject headings the National Library of Medicine adds when it indexes a paper. A paper without MeSH terms gets its model from PubTator 3, NCBI's text-mining service, if PubTator 3 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 is one test, with how many of the 545 papers from 2021 to 2025 that mention the formalin test also mention it, and what share that is.
Papers from 2021 to 2025 that mention both tests
To count the papers that mention three or more tests together, start from the formalin test in the test battery tool.
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.
Neuronal basis for pain-like and anxiety-like behaviors in the central nucleus of the amygdala.
Pain, 2022. 47 citations.
Behav Pharmacol, 2021. 44 citations.
Cells, 2022. 42 citations.
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/resources/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/resources/data/behavioral-tests/formalin-test},
note = {Data set, released November 10, 2026},
}