I need to cover up hereditary dark circles (they're like a purplish black color, so they're pretty dark) under my eyes, and someone I know reccomended concealer. Does it actually work? If it does, which brand do you reccomend?

MAC studio something or other concealer - the one that comes in the same case as an eyeshadow. It works better than the Benefit one (i think it was called "boing").

concealer definitely works. Use an amber (yellow) concealer to tone and neutralize the dark circles.

yes it works and just go with the brand that matches your skin best

I use concealer and it works pretty good.
Try the blend in liquid kind.