UK, As the clock, strikes midnight on 31st January 2020.
The UK would have officially left the European Union and enter a transition period till 31st December 2020.
During this period, the UK will remain in the EU’s customs union and single market and all rights alongside all obligations of companies and citizens will not be affected.
Further negotiations will be taking place for future trade conditions.
These outcomes remain unclear and can range from a Free Trade Agreement/Mutual Recognition Agreement to the UK dealing with the EU on WTO terms.
But, the UK will not be a member of EU institutional organizations.
MHRA and EU institutions will be updating their guidelines reflecting the outcomes via their website:
https://www.gov.uk/government/organisations/medicines-and-healthcare-products-regulatory-agency