There are a lot of skin whitening products that still contain banned substances such as hydroquinone, mercury and steroids, all of which are readily absorbed by the skin causing hidden dangers such as damage to internal organs. Hydroquinone has been banned for a long time ut some products still contain minute traces to make them more effective. Mercurous chloride is another dangerous compound that is still being found in trace amounts in many skin whitening products as well as steroids that are so readily absorbed by the skin they can damage the liver in no time. These compounds should be avoided at all costs so you do not risk getting liver failure or other more dangerous side effects. Be sure to read labels and ask questions for proprietary products that come from dermatologists for they may also contain harmful chemicals they are trying to add to boost efficacy of their products.