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The Differences Between Moisturizers & Serums

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.


While a serum is similar to a moisturizer in regards to promoting moisture retention, it offers vastly more benefits than a lotion alone.
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.

Serums 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 moisturizer reduces the effects of water loss through skin either by attracting moisture or by trapping it.
Moisture-attracting products fall into one class: "humectants", and these work because they contain oxygen-hydrogen bonds that are constantly looking to create additional bonds with water.
Moisture-trapping products can fall into one of two categories: "occlusives" or "emollients".

Emollients & Occlusives

Emollients are the products we most commonly know as "lotions".
Occlusives are a class of moisturizer that includes products like mineral oil, petroleum, petrolatum and paraffin.
They each work in slightly different ways.

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.

Why do we need any of it?

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

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.

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.