Glycerin

Many complicated ingredients go into our skincare, and the most sciencey-sounding and exotic ones are the ones we're generally most excited about, and see splashed across vials, pots of cream, and Instagram ads.

But, long, scientific names (ascorbic acid, what now?) and or exotic origins (blue tansy seed oil, anyone?) aren't everything when it comes to skincare. There are hardworking, behind-the-scenes ingredients that play just as important a role in contributing to healthy, glowing skin, and the one we're talking about today is glycerin. So, what are the benefits of glycerin for skin? Let's dive into it.

What is glycerin?

Glycerin, the commercial name for glycerol, is primarily used as a humectant in skincare products. It's derived from 3 sources: vegetable glycerin, animal fats or synthetics like petroleum (think of that bottle of Aquaphor healing ointment you might have in your medicine cabinet).

Because most of us don't want to use skincare ingredients derived from animals, the most common glycerin in skincare products is vegan glycerin, derived from vegetable oils ranging from corn and canola to coconut and sunflower [1].

In skincare, glycerin is used as a hydrator because it draws moisture from the surrounding environment to your skin's surface. It's been proven safe for use in skincare, has few known side effects, and has demonstrated benefits for almost any skin type.

Whether you have dry, oily or sensitive skin, you're likely to benefit from glycerin in your skincare routine.

So, why don't we hear more about glycerin?

While glycerin is one of the most effective humectants, it's also one of the lesser-known ones. It is frequently overshadowed by its cousin, hyaluronic acid. This famous humectant is a molecule that binds 1,000 times its weight in water, providing an instant plumping effect to the complexion [2].

It's one of those aforementioned buzzy ingredients we see advertised everywhere. But, while hyaluronic acid is famous, glycerin attracts moisture to the skin just as well and has some additional benefits. It's just a little more modest about it.

How does glycerin work?

Glycerin contains multiple hydroxyl (OH) groups in its structure [3]. This sounds sciency, but it essentially means glycerin is hydrophilic or water-loving and, when applied in topical skincare products, will boost hydration levels by drawing water and moisture to the skin — sometimes even from the surrounding air.

But its benefits aren't just on the surface level. Glycerin also helps with the healthy functioning of the skin. Scientific studies have shown that glycerin strengthens the skin barrier, prevents transepidermal water loss, and can even have an antimicrobial action [4]. 

It also accelerates wound healing, making it a perfect solution if your skin has had an allergic reaction or you have a small cut.

What are the benefits of glycerin for the skin?

Any skin type can benefit from glycerin, and it's usually combined with other moisturising ingredients to target specific skin conditions. It can be used in creams packed with oils designed to protect dry skin types or in lightweight water-based formulations to provide non-comedogenic hydration for acne-prone and oily skin types.

Glycerin can be particularly helpful for those living in drier climates and low-humidity areas. It attracts water, boosts hydration, and prevents water loss, creating a seal over the skin when included in moisturisers and serums. This protects the surface layer of the skin from environmental aggressors that can impact skin barrier function.

Because glycerin increases hydration by providing moisture to the stratum corneum, or outer layer of skin, it also provides an instant plumping and smoothing effect. In effect, that instant glow we're all looking for from our skincare products.

Glycerin is an overachiever

Notably, glycerin has outperformed some fairly well-known humectants. A double-blind study examining 197 patients with atopic dermatitis treated dry scaly skin with a cream containing 20% glycerin. They then used a cream containing urea-saline on the other study participants. Skin reactivity was significantly decreased, irritation soothed, and dryness was alleviated more effectively in the group using simple glycerin than in the group using the urea blend [5].

Glycerin is the ingredient that proves the rule that when it comes to skin health, sometimes simple is best.

Is glycerin better than hyaluronic acid?

Glycerin and hyaluronic acid are both effective humectants but work in slightly different ways.

Hyaluronic acid is ultra-lightweight and typically doesn't leave a seal on the skin. Used at the correct molecular weight, it can penetrate the skin more deeply. Evidence has also shown that some forms of the ingredient can increase the penetration of other skincare ingredients, meaning it pairs excellently with other actives [6]. It is available in various molecular sizes; and if you want deep penetration, a multi-weight hyaluronic acid is your best bet.

Conversely, while easily absorbed, glycerin sits on the top layer of the skin and hydrates the stratum corneum. This makes it an excellent choice if your skin barrier is impaired — as well as attracting water to the skin, it also helps maintain the skin's natural moisture barrier. Additionally, glycerin's antimicrobial effect means it brings more to the table for those with acne and rosacea-prone skin [7].

The importance of natural moisturising factors

Notably, both ingredients are natural moisturising factors (NMF), meaning the skin recognises them as part of its own [8]. This is compared to ingredients like vitamin C and retinol, which, while effective for anti-ageing or treating dark spots, can cause skin irritation.

When it comes to glycerin and hyaluronic acid, one isn't better than the other. They both increase hydration; they just achieve it in slightly different ways.

Some of the best skincare formulas combine the 2 for maximum hydration, as hyaluronic acid can penetrate the skin more deeply when used at a low molecular weight and glycerin seals moisture on top of the skin. Think of them as a skincare power couple.

Is glycerin good for all skin types?

Glycerin mimics the skin's natural moisturising factors, which are present in the oiliest and most acne-prone skin, to the driest complexions.

Natural moisturising factors always need to be maintained and supported, meaning glycerin has a place in every skin type's skincare routine. Because the ingredient is naturally oil-free, it also won't clog pores, which is one of the reasons it's so widely used in skincare products.

When and how to use glycerin in your skincare routine

Once you know about glycerin, you'll spot the natural compound in cleansers, moisturisers, body lotions, serums, and even cosmetics. You can use glycerin every day and at any time. In fact, you're using it frequently without even knowing you are.

The ingredient is favoured by dermatologists and cosmetic chemists because it doesn't cause negative interactions with other ingredients and has a low irritation threshold. Any skincare product you use to hydrate your face or body will likely include glycerin.

What skincare ingredients pair well with glycerin?

Glycerin can complement almost any skincare ingredient, from other natural humectants like hyaluronic acid to active antioxidants like vitamin C and niacinamide. When shopping online or in-store, you might notice glycerin sold in its pure form — but it's wise to avoid products that are 100% glycerin-based.

Because glycerin draws moisture from the surrounding area, without being balanced by the water, it can draw moisture out of the skin. This is why you will often find ingredients like rose water included with glycerin, which ensures moisture binding to the skin, not drawing it away.

Another point of consideration when shopping for sophisticated glycerin formulas is texture; applied on its own, glycerin can have a heavy, sticky finish.

Is glycerin good for the skin when used daily?

In short, yes! Glycerin is an excellent ingredient for skin and certainly one to look for in skincare. A glycerin serum, combined with other ingredients will add moisture and glow to your complexion. Particularly for fragile areas like the under eye, which is more naturally vulnerable to environmental aggressors and irritation, it can provide an additional protective boost.

Software's Multi-Peptide Eye Serum is packed with powerful ingredients, including glycerin, peptides and avocado extract, and it attacks under-eye concerns from all angles by stimulating collagen production, diminishing dark circles and puffiness, and reducing the appearance of fine lines and wrinkles.

As a part of your nighttime routine, simply apply a small amount under the eye and around the orbital bone (after cleansing the area). For an additional cooling effect, keep this serum in the fridge instead of your skincare cabinet.

All in all, glycerin is a super effective humectant, and any skincare product or skin type will benefit from its inclusion.