Starter of tree tufts rejected; detox's not half restricting Everyman in regime (6,4)
I believe the answer is:
bloody mary
'starter' is the definition.
(I know that Bloody Mary is a IBA official cocktail)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for bloody mary that I've seen before include "Tomato juice and vodka" , "Nickname of Henry VIII's first daughter" , "Queen regarded unfavourably" , "The Red Queen" , "it could be an eye-opener" .)