it depends on what skin shade you have
in our training
the concealer is said to use for both dark circles and blemishes
if u were to cover up blemishes, i`d recommend you to use it with your fundation, like blend the two together to create a most natural shade
hope that helps
its pretty good for dark circles coz it`s quite hydrating at the same time, so it doesn`t dry up!
other good concealers that i`d recommend include:
laura mercier, bobby brown
and maybe YSL (just coz everyone uses it)
cheers