Humectant: A humectant is anything that can attract and retain water, and is thus the ingredient that forms the foundation of a moisturizer. One of the primary reasons for why moisturizers are most effective after a bath is that the humidified skin surface provides abundant amounts of water to for the humectant to retain.

Barrier: In addition to the ability to keep water inside the skin, moisturizers should also be able to keep contaminants and irritants out, as these can cause inflammation and weaken the skin’s natural defenses. Moisturizers can also sometimes provide a barrier function against ultraviolet radiation.

Restoration: Many moisturizers contain additives that provide additional benefits. While this is more of an optional function from this perspective, it has become so commonplace in modern products that you can pretty much consider it a core component of moisturizers. However, as you may suspect, just because moisturizers add an ingredient and claims that it does something, doesn’t mean it always happens. We will give some examples of this below.

What types of moisturizers are there?

Moisturizers are generally characterized by their composition of water, lipid, and emulsifiers, ranging from pure water (yes people sell aerosolized water...) to balms. Here’s a list of some of the most common types in rough estimates: