By law, ingredients in a product must be listed by order of concentration. That means if it says water first, that water makes up the most of your product. As you go down the list, the concentration of the ingredient diminishes.

Worth noting, however, is that if a company has a patent on the ingredient list of their product, they are not required to follow the order-by-concentration rule. And for all products, ingredients at a concentration less than 1% can be listed in any order -- at the end of the list -- so you'll often see companies place the more favorable items first. So what does this mean for finding the right moisturizer for your face?

The most expensive products aren't always the best, especially since you're often paying for a brand name or special packaging. Though some swear by natural ingredients, science has given us amazing developments in skincare, and natural can't always give you the same results (though it may be more expensive). The most important thing to note on a product is the first five ingredients listed. If there are "active ingredients," higher quality products will typically have a higher percentage of that ingredient, but if you're simply looking for a moisturizer that will work best, check out your first five.

A good moisturizer will do two things: seal in moisture to your outer skin layers, and draw water from the inner layers of your skin to reach the outer layers. Key ingredients to seal in moisture are petrolatum, mineral oils, lanolin and dimethicone. Drawing moisture from within is done by propylene glycol, glycerin, protein and vitamins. It's imperative that something from each of these lists are in the first five -- or else you may not get the desired results.

For really dry skin, look for AHA (alpha hydroxy acid), because it will exfoliate your skin while the product moisturizes. A few other things to note: always, and we mean ALWAYS, choose a moisturizer with built-in SPF. Depending on your skin's sensitivity, check for non-comedogenic (won't clog pores), hypoallergenic (gentle for your skin) and oil-free if you're prone to shine and breakouts.

So here's the deal: don't assume that just because it's pricey, it's the best. Always check ingredients, and trust your own skin! Reading the label and don't have a clue what those parts do? Be enlightened by this amazing ingredient dictionary.