There are many products that you can use to care for your skin. You could even have a 20-step routine. Are they all necessary? Most likely not. Although it may seem simple to apply a daily moisturizer to your skin, in order to properly care and treat any lingering irritations, dehydration, or texture problems, you need to be familiar with the main types of moisturizing ingredients: humectants and occlusives. We have enlisted a few experts in skin care to help you understand these terms.

Although these ingredients have similar effects on your skin, their functions are not the same. First, Dr. Zeichner MD, FAAD is a New York-based dermatologist who says that humectants act as a sponge. “They bind with water to pull it in the outer skin layer.” He explained that emollients are used to soften the skin’s surface and prevent water loss. He adds that occlusives are substances that create a protective layer over the outer skin layer to prevent loss of moisture.

Winter is coming and with the increase in dry and dehydrated skin, now is the time to review when products that contain humectants and occlusives should be used. Here’s the scoop on each.

Humectants

Dr. Michelle Henry MD, a New York-based board-certified dermatologist, says that humectants “absorb water and keep it locked in the skin.” This helps to maintain skin’s moisture. The most popular options for dry to normal skin are hyaluronic, glycerin and lactic acids.

However, Dr. Macrene Alexiades MD PhD is a triple board-certified dermatologist from New York. She clarifies that all products that claim to moisturize will contain some form of humectant.

A humectant is a product that can help your skin determine if it’s dehydrated. Dr. Alexiades suggests pinching your skin to determine if your skin is dehydrated. If your skin does not retract, it could be a sign that your skin has lost its hydration. This type of ingredient is best for skin that has a little bit of water but not enough to cause severe dehydration, such as painful cracking. You can also use this ingredient daily to maintain your skin’s moisture and prevent dryness.

Sofie Pavitt, a NYC-based esthetician, says that if you use a serum with high-quality humectants (which is undoubtedly the most common delivery method), you will need to sandwich it between your skin and an emollient. This is how it works: You won’t just apply a hyaluronic acids serum to your skin and call it good. To prevent further water loss, you will need to apply a moisturizer.

Emollients

Here’s more information about emollients. These are similar to humectants but have some key differences. This category of ingredients is all about adding moisture and preventing water loss. They work best when used in combination with a humectant that locks in water. Pavitt describes them as “like a blanket that holds all your products in their place.”

Emollients can soften skin because they work to repair skin’s barriers. Dr. Zeichner says that emollients are great for dry and flaky skin. These ingredients can be used on all skin types. These are your creams and moisturizers.

Dr. Henry says that ceramides are the most popular emollients. Ceramides, which are lipids or fats that form part of the skin’s barrier, can be summarized as follows: There are many benefits to ceramides, including keeping your skin moisturized, soft, and smooth. Argan oil, which promotes smooth skin, and vitamin E (which is a godsend to reduce wrinkles), are two other popular emollients.

Another popular emollient is lanolin. Dr. Zeichner states that lanolin is an oily compound, which is made from sheep’s wool, and can be used as a moisturizer, or balm. He explains that lanolin is responsible for protecting sheep’s skin from water and can be applied to human skin to soften or protect.

No matter what product you choose, the ever-popular Emollients are a must-have this winter. They will keep your skin soft and free from irritation.

Occlusives

Occlusives are more effective than the other two types. They prevent water loss and can be used to treat extreme dryness and dehydration. Dr. Alexiades explained that occlusives are the most heavy and moisturizing. They work by creating a protective layer on the skin’s surface, much like a shrink wrap.

A petroleum jelly is not a good choice for under makeup. They can also clog pores, so people with oily skin should avoid using them.

Dr. Alexiades says that occlusives can be very helpful for those with compromised skin barriers, such as eczema and psoriasis. She says that anyone with a compromised skin barrier needs occlusives to help them get it back in place. If a humectant and emollients aren’t enough for you, an occlusive could be beneficial. It provides a stronger physical barrier to protect the outer layer of your skin from water loss. Pavitt says that occlusives are useful in cold weather as they prevent environmental factors (such as pollen and cold air) from drying your skin.

Winter is coming and with it, dropping temperatures, low humidity, and steam heat — all of which can dry your skin — understanding how to navigate the different types of moisturizing or hydrating ingredients could be key to keeping your skin healthy, happy, and free from irritation.