All forms of Brexit are bad for health, but some are worse than others. This paper builds on our analysis using the WHO health system building blocks framework to assess the likely effects of Brexit on the NHS in the UK. We consider four possible futures: (1) a "No Deal" Brexit under which the UK leaves the EU on 29 March 2019 without any formal agreement on the terms of withdrawal; (2) the Withdrawal Agreement, as negotiated between the UK and EU and awaiting (possible) formal agreement, which provides a transition period until the end of December 2020; (3) if the Northern Ireland Protocol's 'Backstop' comes into effect after the end of that period; and (4) the Political Declaration on the Future Relationship between the UK and the EU. Our analysis shows that a No Deal Brexit is significantly worse for the NHS than a future involving the Withdrawal Agreement, which provides certainty and continuity in legal relations while the Future Relationship is negotiated and put into legal form. The Northern Ireland 'Backstop' has variable impact, with continuity in some areas, such as health products, but no continuity in others. The Political Declaration envisages a future relationship which is centred around a free trade agreement, in which wider healthrelated issues are largely absent. All forms of Brexit, however, involve negative repercussions for the UK's leadership and governance of health, both in Europe and globally, and significant harmful consequences for the ability of parliament and other stakeholders to scrutinize and oversee governmental actions.