The UK has long been hailed as one of the world leaders in animal welfare. Within the UK, animals used in experiments are provided some protection under the Animals (Scientific Procedures) Act 1986 (ASPA). This Act was impacted by European Union (EU) Directive 2010/63/EU, and subsequently the ASPA was updated to reflect any changes required. While the Directive is very similar to the protection the UK already afforded to animals used in experiments, there were some advances that the Directive provided that were not present in the ASPA. On paper, the changes introduced were promising but may not have been achieved in practice. In 2016, the British public voted to leave the EU, which presented concerns over animal welfare protection and legislation provided by EU law. With the completion of Brexit, there may be an opportunity to diverge from the Directive to advance protection for animals used in experiments. This article explores the influence that the EU has had on animal experimentation in the UK, the potential implications of Brexit on the welfare of animals used in experiments and suggests ways in which this protection can be progressed, with potentially more freedom to amend or introduce legislation to do so.