What is Serum and How to Use It

Gel drops forming on a blue background

Serum is one of those steps that many people who abide by a standard skincare routine skip; maybe because they don’t know what it is, maybe because they don’t want to add one more step, or maybe because it can be one of the pricier skincare products. Those who skip serum, though, are missing out on this tiny product’s big potential. Serum has a multitude of benefits for the skin that are well worth the extra few seconds and dollars spent. Plus, a little goes a very long way.

If you’re wondering what is serum, why you should use it, and how, you have come to the right place. Keep reading to discover the incredible skin-boosting benefits of serum.

What is Serum?

A face serum is typically a gel, oil, or lightweight cream that contains a high concentration of skin-boosting ingredients. While a moisturizer or clean beauty toner may include some of the same ingredients, a serum generally contains them in greater potency or associated with additional powerful actives for greater results. It’s used to target specific skin concerns, so what skin-boosting ingredients are highly concentrated depends on the particular serum.

While most are familiar with the benefits of including a cleanser or a moisturizer in their routine, many don’t realize the incredible benefits—we’re talking visible results—that incorporating a serum can have.

The Benefits of Serum

You may now be trying to decide, “what serum should I use?” The great thing about serum is that it is not one-size-fits-all. Serums are created for individual skin types and goals. If you're looking to boost hydration in the skin, for example, you may want a hyaluronic acid serum. So, when you reach for a face serum, you should reach for one that contains active ingredients that address your specific skin concern, be it fine lines, dark spots, uneven texture, or blemish scars, to name a few. Yes, a serum can fight any of these skin concerns and more. Here are just some of the many benefits serums boast:


One of the first times people begin to seek out powerful skincare products is when they begin to notice signs of aging. You know the signs: fine lines around the nose and mouth or on the forehead, areas of hyperpigmentation or sun spots, skin that feels thin and sallow, etc. While aging is a natural process we all go through, we can help support our skin with serum so that it doesn’t show these signs prematurely or pronouncedly.

Keep Young And Beautiful™ Firming And Smoothing Serum helps fight the first signs of aging with ingredients that help improve firmness like Hexapeptide 11 and the appearance of wrinkles like Rosehip oil, which is a source of Vitamin A. With a facial serum such as this, skin can look more plump and hydrated.


A brighter complexion isn’t only attainable with a good night’s sleep and a smile. A serum with Vitamin C can help too. You're likely familiar with this vitamin but may wonder, “what does Vitamin C do for your skin?” This powerful antioxidant helps protect from environmental damage and brighten the skin. Serums that contain Vitamin C are a great option for those looking to brighten their complexion, even their skin tone, and help protect against visible sun damage or other harmful environmental factors. Try our Radiance Perfection Serum to experience the power of Vitamin C. Not only does it leave skin looking brighter, but it also lightens the appearance of hyperpigmentation and dark spots.

Your face isn’t the only skin that deserves brightening, though. A body serum such as our AHA Smart Renewal Body Serum can leave you with visibly brighter skin all over. AHAs, like the ones found in this skincare product, naturally exfoliate the skin, ridding it of dull, dead skin cells to reveal a radiant glow.


A serum can also benefit your skin by soothing it. If you have sensitive skin and experience redness or irritation regularly, a soothing serum is a great product to add to your routine. A lot of irritation to the skin is due to a weakened skin barrier, which allows moisture to escape. The right serum cannot only help calm irritated skin but help support your skin barrier repair process to prevent future irritation.

One of our favorite products for helping reduce the appearance of redness and irritation and strengthening the skin barrier is Evercalm™ Anti-Redness Serum. This calming formula features Kelp extract, Lingonberry seed oil, and Arnica Flower extract to keep redness at bay, boost hydration, and build the skin’s resilience over time.

Blemish Reducing

Battling breakouts? Yep, there’s a serum for that too. Ingredients such as willow bark, a naturally derived precursor to salicylic acid, work to unclog pores gently to help reduce future blemishes. Prebiotic ingredients also help reduce blemishes by promoting a healthy balance of bacteria on the skin. You can find both of these blemish-battling ingredients in our Clearcalm Non-Drying Acne Treatment Gel. This powerful serum is perfect to use at the first sign of a blemish.


Serums can be extremely hydrating to the skin as well. If you suffer from dry skin, you may need to look further than your regular moisturizer to a hydrating serum that can penetrate the skin’s surface and help it retain more moisture.

Look for a serum that contains rich fatty acids that will help strengthen the skin’s natural barrier, which will not only deliver hydration but also help prevent moisture loss. With Bran Oil, Camelina Sativa Seed Oil, Rosa Canina Fruit Oil, and Plukenetia Volubilis Seed Oil, the Vita Mineral™ Omega 3 Optimum Skin Oil is an intensely moisturizing option.

Hyaluronic acid, often listed as Sodium Hyaluronate, a compound found naturally in the body, is another great ingredient to be on the lookout for if you want your serum to combat dryness. Super-charge your skin with moisture by using Flash Hydro-Boost Instant Plumping Emulsion, which features this ultra-hydrating ingredient.

How To Use Serum

These are just five of the incredible benefits adding a serum to your skincare routine can bring. To get the most out of a serum, though, you need to know how to use it properly. Follow these few tips to learn how to use a serum most effectively.

Step 3 in Your Routine

Serum should be applied after both cleansing and toning your skin. Morning and night, cleanse your skin, apply toner, wait for it to soak in, and then apply your facial serum. Follow up your serum with a moisturizer to supply your skin with hydration.

Less is More

A little goes a long way with serum. Remember, a serum contains a potent amount of active ingredients, so you don’t need a lot of it to see results. A few drops or a single pump of serum is plenty. Drop the product onto your fingertips or directly onto your skin and gently press it into your skin, focusing on the areas that need it most. For example, a blemish-fighting serum can be applied all over but will go further when applied to the areas that need it most, such as along your jawline and T-zone.

Pay Attention to Ingredients

When applying serum, when you use it—day or night—does matter. Some ingredients such as peptides will be more effective when they can work while you sleep when your skin’s natural regeneration process takes place. Therefore, you may want to apply a retinol serum at night. Some ingredients such as AHAs and BHAs will make you more sensitive to the sun and should also be applied at night. Other ingredients such as Vitamin C protect against environmental factors and should be applied in the morning.

It’s also important not to apply too many serums at once. First, certain ingredients can work against each other, thus reducing the effectiveness of any single serum. Secondly, your skin can only absorb so much at any given time. Avoid doubling up on serums, and instead, alternate using them. For example, only use certain serums in the morning and others at night. You can also alternate using different night time serums every other night or every few nights. You can use one serum all of the time and swap it out with another serum as needed, too, i.e., when your skin is particularly dry or irritated.

Embrace this Powerful Product

If you didn’t understand what serum was or why you should use it at the start, we hope we’ve convinced you of this little product’s power. Now that you know what it is and how to use it, the next step is determining which serum is right for you. Then, you can begin incorporating it into your routine and seeing results. What are you waiting for?


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About the Author

Camille Poggi is a doctor in Pharmacy (PharmD.) and is passionate about skincare and how the skin works in general. She specializes in the cosmetic industry and worked for renowned companies in France like L’Oréal and Chanel before moving to London. After being a training manager for 4 years, Camille is at ease with explaining how products work in the skin and how to adapt her speech according to the audience.

She joined REN in January 2020 as International Training Manager and moved to the Research & Development team earlier this year to be the new Scientific Education Manager. A tailored-made role where she assesses and leads all technical communication and ensures scientific compliance is always met. She’s also involved in new product development from the earliest stages. Finding a way to create sustainable skincare products and making sure the message is properly delivered and understood is definitely a big challenge but also her favourite part working for REN.