$$$ Estee Lauder Advanced Night Repair Concentrate Recovery Boosting Treatment ($85 for 1 ounce) serves as a partner product to Lauder's enduring Advanced Night Repair serum. This concentrated version (supposedly with five times the amount of patented recovery complex than the original Advanced Night Repair) is meant to be used for three weeks, after which you revert to your usual routine of applying original Advanced Night Repair. Considering that the price for the Concentrate is double that of the original Advanced Night Repair, you may wonder if this allegedly more potent version is worth the upgrade. It turns out that the formulas are similar in some ways, but the differences are notable enough to definitely make Advanced Night Repair Concentrate the superior product, and not only for three weeks. Its silicone content gives the Concentrate a silkier texture than the original, but the big difference is in the larger amount of antioxidants Lauder packed into the Concentrate version. This is enough of a difference to consider the original antiquated. Whether or not the extras are worth the money is up to you. Clinique's Repairwear Deep Wrinkle Concentrate for Face and Eye ($55 for 1.4 ounces) is just as well-formulated, as is Estee Lauder's Perfectionist CP+ ($55 for 1 ounce).

One more point: A major ingredient in the Advanced Night Repair Concentrate and in the original Advanced Night Repair is bifida ferment lysate. The bifida portion refers to bifidobacteria, a strain of bacteria found in the human body, and believed to provide immune protection and prevent gastrointestinal problems (in other words, it's a friendly strain of bacteria). How does it relate to skin care? Claims made for this ingredient is that it can do for the face what it does for the body, enhance the immune system, and decrease bad bacteria. There is no published information establishing that to be true. Oral consumption of this bacteria (it is often present in yogurt and can be purchased in supplement form) has a couple of studies showing it can be of benefit in helping with infant eczema, but that's about it when it comes to skin (Source: naturaldatabase.com).

Source: Paula Begoun