Info sources: Adverse drug reactions

Last updated: February 10, 2020

BNF – look up each drug and see 'side effects' section; they are listed according to frequency of occurrence.
Drug Safety Update (MHRA) – national alerts and advice about medicine safety. 
EMC – section 4.8 of every SmPC is 'undesirable effects' listed according to frequency, but other sections may have safety info as well.
Yellow card reporting – professionals and patients can report side effects to the MHRA online.