Cannabis lovers head for sativa hair products (7)
I believe the answer is:
stoners
'sativa hair products' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'cannabis lovers head for' is the wordplay.
I cannot really see how this works, but
'for' could be 'to' (eg both can mean 'in the opinion of') and 'to' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for stoners that I've seen is " #They killed Stephen".)