The ARRIVE guidelines, explained.
A plain-English guide to the reporting checklist behind reproducible in vivo research: what the Essential 10 are, how the 21 items fit together, and how ARRIVE relates to the 3Rs.
What are the ARRIVE guidelines?
ARRIVE — Animal Research: Reporting of In Vivo Experiments — is a checklist of the minimum information that should be reported in any publication describing animal research, so studies can be evaluated and reproduced. First published in 2010 and updated to ARRIVE 2.0 in 2020, it is developed and maintained by the NC3Rs. ARRIVE 2.0 is organised as an Essential 10 — the items that must be reported in every study — plus an 11-item Recommended Set, for 21 items in total.
- First published2010
- Current versionARRIVE 2.0 (2020)
- Total items21
- Maintained byNC3Rs
The ten items every in vivo study must report
The Essential 10 are the core of ARRIVE 2.0 — the minimum a reader needs to assess whether a study is reliable and whether it can be reproduced.
- 1
Study design
The groups being compared, the experimental unit, and how the experiment is organised.
- 2
Sample size
How many experimental units are in each group, and how that number was decided.
- 3
Inclusion and exclusion criteria
The rules, set in advance, for which animals and data points are included or excluded.
- 4
Randomisation
How animals were allocated to groups, and the method used to reduce selection bias.
- 5
Blinding
Who was unaware of group allocation while conducting the experiment and analysing the results.
- 6
Outcome measures
The defined primary and any secondary outcomes the study was designed to assess.
- 7
Statistical methods
The tests used for each analysis, and how the assumptions behind them were checked.
- 8
Experimental animals
Species, strain, sex, age or developmental stage, weight, and source of the animals.
- 9
Experimental procedures
What was done to each group, in enough detail for another lab to repeat it.
- 10
Results
The outcome for each group, reported with a measure of variability or precision.
The remaining 11 items form the Recommended Set, adding context such as ethics, housing and husbandry, and protocol registration.
Why ARRIVE reporting matters
Good science that is reported badly can't be trusted or repeated. ARRIVE is how the field keeps in vivo research transparent.
Required by journals
Many journals ask authors to complete an ARRIVE checklist at submission, so reviewers and readers can judge whether a study is reported completely enough to evaluate.
Built for reproducibility
Incomplete reporting is a leading cause of irreproducible animal research. The Essential 10 cover the details another lab needs to repeat or build on a study.
It complements the 3Rs
The 3Rs govern how animals are used; ARRIVE governs how the work is reported. Poor reporting wastes animals by making studies impossible to reproduce.
A reporting standard, not a law
Unlike the 3Rs, ARRIVE is not written into legislation. It is the field's agreed minimum for transparent reporting, enforced through journals and funders rather than statute.
ARRIVE reporting as a byproduct of recording
Most of the Essential 10 is metadata a lab already produces. LabArk captures it as structured data while you work, so ARRIVE reporting stops being an end-of-project reconstruction.
Capture the Essential 10 as you record
Species, strain, sex, age, sample size, procedures and outcomes are captured as structured fields while the study runs, not reconstructed from cage cards months later.
Reporting pulls from structured data
When the ARRIVE items live in structured records, preparing a reporting-ready summary means exporting what you already entered, instead of rebuilding it before a deadline.
One record, from licence to manuscript
The same durable record supports AWERB review, 3Rs returns and ARRIVE reporting, so the details stay consistent across every stage of the study.
ARRIVE guidelines: frequently asked questions
What are the ARRIVE guidelines?
ARRIVE (Animal Research: Reporting of In Vivo Experiments) is a checklist of the minimum information that should be reported in any publication describing in vivo animal research, so the work can be evaluated and reproduced.
What is the ARRIVE Essential 10?
The Essential 10 are the ten items ARRIVE treats as the minimum that must be reported in every in vivo study: study design, sample size, inclusion and exclusion criteria, randomisation, blinding, outcome measures, statistical methods, experimental animals, experimental procedures, and results.
When were the ARRIVE guidelines published?
The original ARRIVE guidelines were published in 2010. The current version, ARRIVE 2.0, was published in 2020.
How many items are in the ARRIVE guidelines?
Twenty-one in total: the Essential 10, plus an 11-item Recommended Set that adds further context.
Are the ARRIVE guidelines mandatory?
They are a reporting standard rather than a law. Many journals and funders require an ARRIVE checklist for in vivo research, but ARRIVE is not embedded in legislation the way the 3Rs are.
What is the difference between ARRIVE and the 3Rs?
The 3Rs are the ethical framework for how animals are used. ARRIVE is a reporting checklist for how in vivo experiments are described, so studies can be evaluated and reproduced.
Who maintains the ARRIVE guidelines?
They were developed and are maintained by the NC3Rs, the UK's National Centre for the Replacement, Refinement and Reduction of Animals in Research.
One record. Every step of the study.
Capture the Essential 10 as you work, and keep your reporting ready by default.