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The Differences Between Moisturizers & Serums

Over the years, we've noticed that the terms "moisturizer" and "serum" tend to be used almost interchangeably. So are serums and moisturizers similar? Should they be used in combination or separately? And why do we need either? Let's get right down to it.

A serum and a moisturizer are not the same. Although a serum can technically take the place of a moisturizer because it contains ingredients that are designed to promote moisture retention, moisturizers and serums are not interchangeable.

Moisture retention is vital to skin health, which is why we strongly recommend the use of a daily moisturizer for all skin types.

What is a moisturizer?

Moisture-trapping products either fall into the category of an "occlusive" or an "emollient".

Why do we need any of it?

As water travels upward through the epidermis, skin's moisture is naturally lost. Depending on your age, location and skin type, this normal daily loss can range from minimal to severe.

Emollients vs. Occlusives

Emollients are products we most commonly know as lotions while occlusives are a class of moisturizer that includes products like mineral oil, petroleum, petrolatum and paraffin. Both of these work by trapping moisture in your skin, although the process is slightly different for both.

A traditional emollient moisturizer works by penetrating skin to cement gaps created when the links between dead skin cells are broken. Occlusives such as Vaseline sit on top of the skin and won't absorb readily.
An occlusive tends to be a good fast-working solution to severely chapped lips, hands or feet, but because it's derived from crude oil and can lead to clogged pores, we wouldn't recommend it as a long-term everyday solution.


As you can see, moisturizers already provide effective ways to help retain skin's moisture. So where do serums come in?

While a serum is similar to a moisturizer in regards to promoting moisture retention, it offers vastly more benefits than a lotion alone.
Serums also contain powerful ingredients designed to nourish, replenish and rejuvenate your skin, such as Vitamins C & E, antioxidants, botanicals, anti-aging or skin-firming ingredients.

A serum's small molecules combined with its high concentration of ingredients means that more nourishment is able to penetrate more deeply than with a regular lotion, providing highly effective ways to reduce fine lines, rejuvenate skin and restore balance.
Because serums contain ingredients that become unstable when exposed to light and air, they should be stored in a climate-controlled space without too much exposure to light.
In order to avoid ingredient breakdown from light exposure, Skin Obsession always uses amber bottles which prevent breakdown. We recommend that you apply your serums at night before bed when exposure to natural light can be avoided in order to reap the full effects of a serum.

Whether you choose a serum or moisturizer to help retain your skin’s moisture is up to you. The key difference in these products lies in their ability to penetrate your skin in order to deliver valuable ingredients designed heal, restore and renew.
Use a daily lotion to lock in or attract moisture, and add a serum chockfull of powerful ingredients to amp up your skin care routine.