Before we get started, a couple of things:
Before you buy anything, make sure you read the disclaimer. Many companies make it clear in the product's terms and conditions that they are not medical doctors. Most products listed are not FDA approved, and they often contain questionable ingredients. The FDA regulates cosmetic drugs, cosmetics, and other medical devices. The products reviewed are meant for healthy and attractive people who have a variety of skin conditions. Most of them are not available over the counter. The FDA's guidelines for selling drugs can be found here. The FDA also has a very specific guideline for cosmetics: "FDA requires that cosmetics marketed as therapeutic or nontherapeutic cosmetic items be evaluated for their ability to prevent, detect, or treat the following serious adverse effects, if they are indicated for or are recommended to be used in place of treatment: photodamage; cutaneous sensitivity; dryness, flaking, or peeling; dry skin; skin rash; irritation; sunburn; and erythema multiforme." And it recommends "that cosmetic products, except where prescribed by a licensed physician, not be used for skin disorders that are not a direct result of an external cause (eg, pregnancy, pregnancy-related conditions, or certain types of dermatological disorders such as eczema)."
That's why we don't suggest products that claim to "improve appearance" in our Skin Deep website, where we highlight some of the more popular options that may work.