A simple way to slightly lighten your skin is to apply a weak bleach to your face daily. This is easy, cheap, and easy to obtain.
All you need to do is apply lemon juice to your face every night, then wash it off after 15 minutes. If the lemon juice by itself stings too much, or overly dries your skin, you can make a mask by mixing together plain yogurt and lemon juice and washing it off after 15 minutes. It won't be instantaneous, but after a few days, you will notice your skin starting to lighten a little.
Just a little warning, if you apply the mask during the day, do not go into direct sunlight with the mask or lemon juice on. Also wait at least twenty minutes after washing it off before exposing yourself to sunlight as well. The citrus in the lemon juice can react with the sun light and make your skin splotchy, so that is why it is best to do at night.
What you are asking is to literally decrease the amount of melanin within you. The more you have, the darker you are. It's a chemical released from cells within your skin.
Becareful with whatever products you try. Any product can make you blotchy or give an undesired reaction. I cannot understand how a cream or juice would be able to stop the production of melanin without destroying the cell that creates it. And frankly, these creams and juices cannot destroy EVERY cell, thus giving you a blotchy appearance or not working at all. It's a far more complicated process reguarding your skin color than many people think and you are literally messing with the cells within your skin.
Just something to think about from the scientific point of view.
First off I dont know your specific situation,but when I was a child I wanted to lighten my skin as well.My father was Native American.and my mother was half,so I came out looking like a mix ,I have Dark skin almost as dark as a full blood.Black hair,and green eyes(no body anywher in my family has green eyes)I live in the southern U.S. and and color discremination was in FULL effect when I was young,so I was made fuun of often at school because I was dark skinned,also I wasnt dark enough to fit in with the African american,so I caught it from them as well.As I grew older my grandparents began to tell me that I was special because I encorperated the best of both races,No I didnt believe it either,.Untill high school(I found girls realy liked Long black hair and green eyes!lol)My point is I dont know why you want to lighten your skin,but for me I found some peace in the fact that millions of people spend billions of dollars every year,on tanning booths,tanning creams,and beach front homes trying to get what I already have.I am sure your situation is different,but Im also sure there is something about you that makes you special,unique,no matter hat your skin color...just my 2 cents...Peace