I use both the Creme and the Youth Activating Concentrate. I could just use the Creme, but I find the Concentrate some how tightens my skin and allows me to use less of the Creme. Actually, during the winter, I could just use the Creme after using the Lancome moisturizing toner like the Lancome rep did on my face to prep my skin for the Teint Miracle liquid foundation. The toner and the Creme made my skin baby soft without any greasiness. Really nice. So, the answer is yes, you can use the Creme without using the Concentrate or the Serum. I would highly recommend using the Lancome moisturizing toner (pink) before applying the Creme for maximum effectiveness. This moisturizer has been quite effective for me. Consider getting a sample and trying for yourself. Different individuals may have different responses depending on their own skin type.

Yes, absolutely! They work well together, but you don't need the serum under the night cream. It is quite potent on its own.

buy the serum only and use under your regular moisturizer; the cream is a waste of money (moisturizing but no anti-aging results). and actually the eye cream is amazing. (im an eye doctor) hope this helps!

Not yet that I have seen, but this one will last you a long time. I average 4-6 months, depending on the season (I put it on thicker in the winter months).

No. Spend the money on this one. I save for it. It's my most important splurge. I have tried lesser quality ones that seemed to be the same (say by Loreal - made by the same company), but they are not the same at all. Genifique is one of a kind.

I believe this product can be used to prevent the increase of fine lines. I use it in combination with the new Genefique serum for eyes.