First off, what's your skin type? Night Creams are generally thicker, but depending on your skin type, you don't want anything too thick that can clog your pores. Since you're so young, you honestly don't need a whole lot of bells and whistles in your night cream (so you really don't need any fancy/extreme anti-aging). I think you're never too young to start a skin care regimen because the earlier you start, the easier it is to maintain as you get older (and do start to need more heavy-duty products). One of my FAVORITE night creams is still Oil of Olay's Night of Olay Firming Cream. I've tried EVERYTHING (most the ridiculously expensive) and I usually always go back to this. I like it because it does actually firm my skin and make it looking bright, but it's not so thick that it's going to cause breakouts, make my skin feel heavy and congested, or make my face look shiny and oily. It's cheap too! It's about $6-7 for a jar that lasts a long time. It's a great night cream regardless of age!

Night creams don't feature SPF, for starters (obviously, you're not out in the sun when you're asleep for the night). Night creams tend to be "richer" and by that I don't necessarily agree that they are thicker. They tend to be more emollient, and contain additional or different ingredients that are absorbed into the skin while you sleep. Night creams give the term "beauty rest" a whole new meaning. That being said, not everyone needs a night cream, or a night cream from the same line of products that you use during the day. You may not feel that you need something thicker or heavier or even more emollient.. Don't be afraid to mix and match -- just because your favorite day cream has a complimentary night cream doesn't mean you need to use it. The best way to choose a night cream is just to read the label carefully, and ask questions if you're not sure what ingredients are in it or whether or not they're good for your particular skin type.

I believe Olay was my first cream when I was 17 back in GULP 1989. Don't spend a lot. Moisturizing is the key.

Certainly by your mid-20s.

Don't indulge in any cosmetic creams , since you are only 17. Apply olive oil at night around your eyes and massage thoroughly. Remember, olive oil is heavy, so don't forget to add few drops of water in it.

I think you should start as early as possible! Ive been using it since i was about 24 and found that my dry skin became much more moisturized right away! I think now as i'm aging its helping reverse a lot of sun damage i've done to it as well.