I'm thinking of buying diane stalder whitening but I need feedback on how effective it is.

It seems to work best on asian and fair skin. I have used the diana stalder lotion, crème, papaya kojic soap, and glutathione soap and my skin tone is medium brown. I like their papaya kojic soap as it exfoliates really well, helping the absorption of skin lighteners, removed my acne, and help fade my scars. But, the products were not potent enough to lighten my skin and the jars and bottles are very small.