Soybeans contain a whole host of molecules that act on the skin; the key ones are isoflavones (or phytoestrogens) which are potent antioxidants. They also contain protease inhibitors, which are much less known than the antioxidants but no less potent.
Protease inhibitors are biologically active and act as a switch to shut off pigmentation in the skin. Studies have shown that when used over time, they will actually lighten skin tone. In a recent study of 65 women with sun damaged skin, using a daily soy moisturizer was found to be effective in improving blotchy pigmentation, dullness, texture, and overall skin tone when used for 12 weeks.
Aveeno’s Positively Radiant line has daily facial moisturizers and sunscreens which contains these soy extracts. It has a nice light fragrance and the cream dries with an elegant finish. If you are looking for an alternative to chemical bleaching creams or expensive skin lighteners, then I suggest you try this product for 3 months and see for yourself.