You’ve probably heard the phrase “skin is your body’s biggest organ!”, which is a true statement. And while our skin acts like a nice sausage casing to keep all our insides tucked away, it also has other functions. For one, skin has the important task of keeping germs, toxins, UV rays, and chemicals out of the body, like a shield from all the various threats that our environment poses. It also helps regulate body temperature through hot and freezing days alike.

The first of those two core functions—skin’s barrier-like defense—is a common point of discussion in skincare, too. Perhaps you are also familiar with the terms “skin’s barrier function” and “the skin’s moisture barrier”. These two terms are not one in the same, but they are related are are both important to understand. Read on to learn more, and to discover how a good skincare regimen can reinforce both of these barrier facets of skincare.

First things first: It’s imperative to think of skin as armor for the rest of your body, almost like a giant fortress protecting the royal family of organs inside. So, when a skincare product or regimen promises to boost skin’s barrier function, it is referring to this defensiveness against germs and bacteria, toxins and pollution, chemicals, UV rays, and the likes. 

With this in mind, you can work backwards to understand the types of ingredients that are important to reinforce this barrier from the outside. Also, given that skin thins as we age, it is important to use products that fortify the skin as a whole.

SPF: Using a daily SPF 30+ product, like a moisturizer with sunscreen, will move the needle most by neutralizing the incremental exposures to UV rays (which add up over time to mutate skin’s DNA and damage barrier functions). 

Antioxidants: A skincare regimen should prioritize antioxidant-rich ingredients like cactus extract in order to build up skin’s defense age toxins, UV damage, pollution, and more. Most anti-aging assortments will center antioxidants in their formulas.

Healing properties: It’s important that skin heals itself rapidly, so that any cuts, razor burns, or acne blemishes seal off and rebound quickly, in order to keep germs and bacteria on the outs. One of the best ways to obtain healing properties is through a repair-focused night moisturizer, since sleep is also when your body replenishes itself.

Anti-inflammatories: Soothing and calming ingredients will help reducing any inflammation that temporarily compromises skin’s barrier functions. Look for a soothing moisturizer with ingredients like cactus extract or turmeric to temper any such swelling.

Skin firmers: Look for ceramides (usually in eye creams), as well as collagen- and elastin-boosting products that help reinforce skin’s suppleness, resilience, and density. Niacinamide is a great example of a barrier-strengthening ingredient.

There’s something (intentionally) missing from the list of products above: everything pertaining to actual moisture, despite all the mentions of moisturizers. That’s because skin itself requires moisture in order to stay strong, resilient, supple, and to maintain its barrier functions. So, when we talk about skin’s moisture barrier, it can be a more encompassing term for all of the above barrier-like functions, but usually it’s a reference to the outermost layer of skin (epidermis), and the amount of moisture required to keep the lights on. This layer is also sometimes called the acid mantle or stratum corneum.

In this way, think of skin’s moisture barrier as the thing you feel, in terms of oiliness or dryness—as well as a driving force behind the barrier functions. Still, there are obvious signs that your skin’s moisture barrier is compromised, which include dryness, flaking, inflammation, and irritation. 

In order to keep skin’s moisture barrier reinforced, you (obviously) need to prioritize hydrating ingredients. And while literal moisturizers are a key part of any baseline skincare regimen, you should make sure that your entire regimen is helping preserve moisture in the skin—so, a gentle cleanser is another great baseline product, one that nourishes skin while it expunges excess oil, rather than drying skin out. Try to think of your regimen with that totality: Is it adding moisture, and never detracting? You really can’t ever give your skin too much moisture, but it’s very easy to take things the opposite and dehydrating way. Secondly, make sure you’re not doing anything to damage this outermost layer, like over exfoliating the skin or skipping SPF and getting sunburnt. 

For keeping hydration levels high, look specifically for ingredients like cactus extract, hyaluronic acid (which can hold up to 1,000 times its own weight in water), as well as fatty acids such as Omega-3s found in a moisturizer with chia seed extract.