yeah, i believe makari, euoko, fair and flawless, melederm are heavy weights in natural skin lightener so far. i know there are a few others that work well but the top work great for darker skin tones. the only problems with them are that they are super expensive ( you can buy same actives and make your own cream for much less) and they are not permanent.
more a less a good product should give near maximum results in 2 months. some people take a bit longer though. just make sure you do scrubs and peels (make sure they are still gentle on your skin) when doing skin lightening. they maximize the results you get from the creams.