|Picture is for illustration purposes|
So the first thing that you would need to apprehend is that what exactly do you want from through the whitening/brightening system? Reason being on why I ask is actually due to the fact that not all whitening systems have the same purpose. They are actually broken down into the following functions:-
A) Some makes you fair (literally)...BUT if it does not have any properties to combat your dark spots, then being fair may actually emphasise your dark spots even more. This is generally what us youngster are always targeting for :)
B) Some don't actually make you fair. They clear the spots/blemishes on your skin, thus making you seem to "look" fairer. This would involve components like AHA, BHA, nicotinamide (to battle pigmentation)and perhaps Vitamin C
C) Some actually makes you glow healthily from within rather than makes you fair. This is the result of the usage of products that boosts your skin's clarity, plumps up the skin via added moisture and collagen. Thus, a smooth-surfaced skin makes you look fair. This is pretty much open-ended and choices could be as wide as hyaluronic acid, caviar, Vitamin A, Vitamin E...and the list goes on.
So after these functions explained, do you know as to which skin concern you're addressing to? :)