What Is a Facial Serum? Understanding Natural Serums for Every Skin Type

July 09, 2025 by Sarah Villafranco, MD

Are you totally overwhelmed by facial serums? Same! And I’m a natural skincare formulator. If I feel overloaded by options, I can only imagine how confusing it is as a consumer—even an educated one. So, let’s simplify. First, I’ll walk through what a serum actually is. Then, I’ll break down Osmia’s three facial serums by function and skin type.

What Is a Facial Serum?

Let’s start with the actual definition. Serum, in medical terms, is “the watery part of blood that contains antibodies and fights disease.” Another definition is “any watery animal or plant fluid.” So, kind of gross, but also helpful context.

In skincare, a serum is a concentrated liquid—either water-based or oil-based—designed to deliver active ingredients deep into the skin to target specific concerns.

You’ll find water-based, gel-based, and oil-based serums, which makes it tricky to know where they fit in your routine. Generally speaking, the following is true:

  • Water or gel-based serums offer hydration and water-soluble vitamins

  • Oil-based serums deliver antioxidants, oil-soluble vitamins, and help lock in moisture

And just to be clear: oils are not hydrating. "Hydr-" = water. No water = no hydration. Oils soften, nourish, and help the skin retain water, but they don't add water. That’s why you need to apply oils to wet or damp skin—ideally right after cleansing or layering over a water-based product like our Purely Calm Gel Toner.

How to Use a Facial Serum

I recommend applying water-based products first, followed by oil-based ones. Your skin will usually let you know if you’re getting the order right with less irritation, better absorption, and a healthy, balanced feel.

All three Osmia facial serums are oil-based, and all are best applied to very damp skin, or layered over toner for an extra hydration boost.

What Do Osmia’s Facial Serums Do?

Here’s a breakdown of each of our natural facial serums, including who they’re for and why they work.

Balance Facial Serum

Best for: Normal, oily, combination, and acne-prone skin
Also great for: Chest and upper back acne

I formulated Balance to help reduce sebum production and soothe overactive skin. It penetrates all layers of the skin, addressing inflammation and overproduction that can lead to clogged pores and breakouts.

A dermatologist friend of mine from med school tested it and said: “My face has not been this clear and greaseless since pre-pubescent days.”

Key ingredients:

  • Black cumin seed oil is rich in vitamins A, B, and C and thymoquinone, a hugely powerful antioxidant and anti-inflammatory

  • Schisandra and acai are calming to inflamed skin and high in antioxidants

  • Olive squalane, kukui, and macadamia oils absorb quickly and leave the skin soft but not oily

  • Essential oil blend of lavender, geranium, green myrtle, and sandalwood to balance sebum production

What customers love most:

  • The fresh, herbal scent (unisex and grounding)

  • More even skin tone and fewer breakouts

  • Decreased oil production and shine

  • Quick absorption with zero greasy residue

Restore Facial Serum

Best for: Dry, mature, or sun-damaged skin
Also great for: Skin recovering from procedures like peels, lasers, or retinoids

Restore was designed to support skin that’s been damaged over time—especially by sun exposure—or that’s in active recovery. It’s also excellent for soothing irritation from dermatologic treatments or prescription actives.

Key ingredients:

  • Lavender-infused olive oil, organic shea oil, rosehip seed oil penetrate deeply and support healing

  • Pomegranate, amaranth, calendula, and sea buckthorn rich in antioxidants that strengthen collagen and restore elasticity

  • Borage and evening primrose oils deliver essential fatty acids that nourish and calm

  • Lavender, helichrysum, and carrot seed essential oils help relieve inflammation and repair skin

What customers love most:

  • Visibly more even complexion

  • Quick absorption and a soothing scent

  • No irritation, even on sensitive skin

  • Helps heal scars, scabs, and flaky areas

  • “The only thing I could use after a peel—healed my skin so quickly!”

Nectar Nourishing Drops

Best for: All skin types
Especially great for: Adding a nutrient boost to any skincare routine

Nectar is like a vitamin supplement for your face. You can mix it into a moisturizer or apply a few drops directly to the skin for extra nourishment, enhanced hydration, and antioxidant support. It’s gentle, versatile, and made to elevate your routine.

Key ingredients:

Prickly Pear Oil is rich in essential fatty acids and antioxidants, this oil promotes skin elasticity while softening and soothing the skin.

Pumpkin Seed Oil is packed with vitamins E and C and zinc, it helps fortify the skin and support its natural barrier.

Argan Oil is abundant in fatty acids and antioxidants, aiding in nourishing and balancing the skin.

Rosehip Seed Oil is high in essential fatty acids and antioxidants, it nourishes and rejuvenates the skin, improving its appearance.

Sandalwood Essential Oil is known for its calming and soothing effects, helping balance and refresh the skin.

Rose Otto Essential Oil is prized for its soothing, calming, and anti-redness properties, and provides a gorgeous aroma.

Jasmine Extract offers soothing aromatic properties, moisturizing and conditioning the skin.

Need Help Choosing a Serum?

I hope this breakdown made the world of natural facial serums a little less overwhelming. Whether you're looking for the best serum for acne-prone skin, a face oil for post-procedure recovery, or a way to boost hydration naturally, there’s something here for you.

Still not sure which one to choose? We’re here to help—just email us at help@osmiaskincare.com and we’ll get you pointed in the right direction.

 

handwritten signature from sarah
The information contained in this post is for educational interest only. This information is not intended to be used for diagnosis or treatment of any physical or mental illness, disease, or skin conditions. 

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OUR WELLNESS + SKINCARE EXPERT

Sarah Villafranco, MD

Dr. Sarah Villafranco attended Georgetown University Medical School, and went on to complete her residency in emergency medicine at George Washington University. She moved to Colorado, where she practiced as a board-certified emergency medicine physician at Aspen Valley Hospital, Snowmass Clinic, and Valley View Hospital in Glenwood Springs, CO. After losing her mother to pancreatic cancer, she took a local soap making class, and fell in love with the chemistry and artistry of making soap. Sarah went into research mode and was alarmed to learn how many potentially harmful ingredients were in most skincare products on the market. She knew she could make better, safer products that were as effective (if not more so) than conventional products. After a few years of research and development, Sarah stepped away from the emergency room to launch Osmia Skincare in April of 2012. She remains a licensed physician in Colorado, and now helps people find healthier, happier skin as CEO of the brand.