Likely to abuse this kind of pill (9)
I believe the answer is:
plausible
'likely' is the definition.
(synonyms)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for plausible that I've seen before include "Specious" , "Reasonable on the face of it" , "likely" , "Seemingly true" , "False but sounding true" .)