Humectants: An Essential Skincare Step Not to Skip
by Heather Smith on Apr 08, 2023
Humectants are crucial in skincare by providing essential skin hydration and maintaining the skin's moisture balance. These unique molecules attract and hold water, keeping the skin hydrated and healthy.
Derived from natural sources or synthesized in a lab, humectants interact with the skin and environment to ensure the complexion remains smooth and radiant. Understanding the importance of humectants in skincare can help enhance your routine and improve your skin's overall appearance and health.
In this article, I'll discuss how using humectants in your everyday skincare routine can help you easily achieve healthy-looking skin!
What is a Humectant
Humectants are an entire class of ingredient. Each humectant is unique with its own structure and abilities.
Humectants play a crucial role in maintaining skin hydration by working at the molecular level to attract and retain water in the skin.
Hydration = water (absorption and retention)
As ingredients, humectants can be found in all types of skincare products including lotions, moisturizers, serums, toners, and more. They're generally water-soluble, so they will be found in water-based products and emulsions.
The two most common humectants are glycerin and hyaluronic acid, but there are many more. Each has properties that can improve the overall health of your skin.
The physiology of how humectants hydrate the skin can be described as follows:
Attracting water molecules: Humectants are hygroscopic, meaning they attract water from their surrounding environment. They form bonds with water molecules, drawing moisture from the atmosphere or from the deeper layers of the skin (dermis) into the outermost layer (epidermis or stratum corneum). Drawing water to the skin (from the environment) is preferential to drawing it from the deeper layers, but both will help hydrate and plump the epidermis.
Retaining moisture: Once water molecules are attracted, humectants help retain this moisture within the epidermis, preventing it from evaporating. This process, known as reducing transepidermal water loss (TEWL), is essential for maintaining skin hydration and ensuring a healthy skin barrier. They don't share this role alone, however, as it's also an essential feature for other skincare ingredients.
Enhancing Natural Moisturizing Factor (NMF): The skin has its own natural hydration system called the Natural Moisturizing Factor, a complex mixture of various humectants, lipids, and proteins. By supplementing the skin with external humectants, the NMF is enhanced, further improving the skin's ability to retain moisture.
Promoting a healthy skin barrier: A well-hydrated skin barrier is vital for overall skin health. It protects against external irritants and allergens while preventing excessive moisture loss. Humectants contribute to the maintenance of a healthy skin barrier by ensuring that the epidermis remains moisturized and pliable.
Skin hydration is the purpose of using humectants, and having well-hydrated skin is the benefit!
Some of the benefits of having well-hydrated skin are:
- Skin that's plump and elastic will have fewer wrinkles and fine lines
- A healthy skin barrier means you're protected from environmental stressors and skin attackers like bacteria, and you have a healthier microbiome and proper pH of the acid mantle
- Properly moisturized skin requires humectants and emollients, and when used together properly, you'll have:
- decreased redness
- decreased flaking
- decreased irritation
- enhanced glow and complexion brightness
TOP 22 Natural & Plant-Derived Humectants
What exactly does the word "natural" actually mean? Some days, I wonder if anyone knows.
For skincare ingredients, there is a lot of semantics. For example, natural hyaluronic acid gets extracted and purified from animals (rooster combs and fluid from within a cow's eye). It can also be created through bio-fermentation technology using bacteria. Almost all cosmetic hyaluronic acid is produced using biotechnology, which some purists could view as less natural (because a lot of science goes into making it).
As a skincare formulator, I'm always on the lookout for better ingredients. Something might be slightly less natural but better for your skin or the earth - so that's what gets a win in my books.
So, for the purposes of this list, I'll discuss humectants that come directly from nature in an unmodified state (ie. honey) or are plant-derived through some sort of chemical process that doesn't involve animals, petrochemicals, or controversial solvents.
So let's get to it!
Glycerin (vegan sourced): Derived from plant oils, glycerin is one of the best natural humectants. It's a versatile, vegetable-derived ingredient that soothes and moisturizes skin while providing long-lasting hydration. Additionally, this humectant has antimicrobial properties, which can help protect the skin from bacteria and other impurities. Glycerine can be sticky when used in high concentrations.
Hyaluronic acid (vegan sourced): Hyaluronic acid (HA) is a natural substance that is a powerful moisture-holding agent due to its unique molecular features. The building blocks of HA have many parts that can easily form strong links with water, helping it to lock in moisture by forming a water-filled, gel-like network.
Aloe vera: A gel derived from aloe vera plants, it is known for its soothing and hydrating properties. Aloe vera is rich in vitamins, minerals, and amino acids that nourish the skin. Not only does aloe vera help lock in moisture and hydrate the skin, but it also helps reduce redness, swelling, and other signs of irritation on the skin.
Honey: A natural humectant and emollient, honey attracts and retains moisture. Honey has antioxidant and antibacterial properties which protect skin from environmental damage and bacteria that lead to breakouts. Additionally, it's loaded with minerals, vitamins, and enzymes, making it an excellent moisturizing agent for all skin types.
Sugar Alcohols: Sugar alcohols, a group of sweet-tasting compounds, are often used in skincare products for their ability to help retain moisture. Some common examples of sugar alcohols used in skincare include glycerol, sorbitol, and xylitol.
Hydroxy Acids: Hydroxy acids draw water from the air or the deeper layers of your skin and lock it in. Additionally, hydroxy acids are known for their exfoliating properties, which can help remove dead skin cells. Proper exfoliation helps your skin absorb active ingredients, including humectants. AHA, BHA, and PHA all have these hydrating properties; however, my 2 favourites are lactic acid (an AHA) and gluconolactone (a PHA) due to my sensitive skin barrier.
Urea: Although urea is a naturally occurring substance in the body, the urea used in skincare products is synthesized. It is an effective humectant, helping to maintain the skin's moisture balance and promote a healthy skin barrier. Additionally, urea can gently exfoliate dead skin cells, enhancing its skin-rejuvenating benefits. This multifaceted compound is a valuable addition to many skincare formulations, promoting healthy and hydrated skin.
Seaweed and algae: Rich in minerals, vitamins, and amino acids, seaweed and algae extracts can act as natural humectants, nourishing and hydrating the skin.
Snail Mucin: Snail secretion filtrate is a complex mixture of glycoproteins, enzymes, hyaluronic acid, and other biologically active compounds. These components are secreted by snails and help to protect their skin and maintain its moisture levels.
Sodium PCA (sodium pyrrolidone carboxylic acid): A naturally occurring component of the skin's NMF (Natural Moisturizing Factor), sodium PCA is a humectant that helps to attract and retain moisture.
Provitamin B5 (Panthenol): A precursor of vitamin B5, panthenol can attract and hold moisture while soothing and healing the skin.
Allantoin: Derived from the comfrey plant, allantoin is known for its soothing and healing properties. As a humectant, it helps retain moisture and improves healing of minor irritation.
Saccharide Isomerate: A plant-derived carbohydrate complex, saccharide isomerate closely mimics the skin's natural carbohydrate composition, ensuring long-lasting hydration.
Agave nectar: Extracted from the agave plant, this nectar is a soothing, natural hydrator. It's a good option to explore if you are looking for a vegan alternative to honey.
Betaine: Derived from sugar beets, betaine is an amino acid that hydrates and reduces irritation.
Chitosan: A natural polymer from the shells of crustaceans, chitosan has humectant properties and is also known for forming a protective barrier on the skin.
Trehalose: A sugar found in plants and fungi, trehalose hydrates and helps protect the skin against environmental stress.
Beta-glucan is a natural polysaccharide derived from various sources such as yeast, fungi, and cereal grains like oats and barley. It is known for its anti-inflammatory, antioxidant, and immune-enhancing properties. Beta-glucan contributes to improved skin elasticity, suppleness, and overall skin health by binding water molecules and maintaining moisture levels in the skin.
Collagen is a naturally occurring protein obtained from animal sources. Collagen forms a film on the skin's surface, helping to lock in moisture and prevent transepidermal water loss. Due to the large molecular size, topical collagen does not penetrate deeply, so it does not alter the collagen within your skin.
Galactoarabinan is a natural polysaccharide derived from the bark of the larch tree. It's composed of galactose and arabinose sugar units. In addition to the humectant effects, galactoarabinan has been shown to improve skin barrier function, reducing transepidermal water loss and supporting overall skin health.
Propanediol: Propanediol is a colourless, odourless, viscous liquid that functions as a humectant, solvent, and emollient. It is commonly derived from corn or sugarcane through a bio-based fermentation process, making it a more sustainable and eco-friendly alternative to petroleum-derived propylene glycol. In addition, propanediol enhances product texture and feel, improving the overall formulation of skincare products.
Hydrolyzed proteins: Hydrolyzed proteins come from various protein sources, such as plants, animals, or silk. The proteins undergo a process called hydrolysis, where they are broken down into smaller peptides and amino acids, making them more soluble and easily absorbed by the skin. As humectants, hydrolyzed proteins attract and bind water molecules, improving skin hydration and promoting a smooth, supple appearance. Common hydrolyzed proteins used in skincare include hydrolyzed collagen, elastin, silk, wheat, oat, lupine, and baobab protein.
Purely synthetic humectants are chemically engineered substances that are not derived from natural sources. They serve a similar purpose as natural humectants in skincare by attracting and retaining moisture. Here is a list of some common synthetic humectants:
Propylene glycol: Most of propylene glycol is produced from propylene oxide derived from petroleum-based feedstocks. An alternative, more eco-friendly method for producing propylene glycol involves using renewable, plant-based feedstocks, such as glycerin from biodiesel. It's important to note that propylene glycol, regardless of its origin, may cause skin irritation or sensitivity.
Polyethylene glycol (PEG): PEGs are a group of polymers derived from petroleum that function as humectants, emollients, and emulsifiers in skincare products. They vary in molecular weight and viscosity, affecting their ability to moisturize and provide a smooth texture.
Butylene glycol: A synthetic alcohol derived from petroleum, butylene glycol is used in skincare products as a humectant and solvent. It helps to retain moisture and improve product texture and penetration.
Glycereth-26: A synthetic version of glycerin, glycereth-26 is a humectant and emollient used in skincare products to attract and lock in moisture while providing a smooth and silky feel. It can be synthesized from vegetable sources, but also from petrochemical.
Dipropylene glycol: A synthetic, petroleum-derived substance, dipropylene glycol is used as a humectant, solvent, and fragrance stabilizer in skincare products. It helps to retain moisture and improve product texture.
Hexylene glycol: A synthetic alcohol, hexylene glycol is a humectant, solvent, and emulsifier in skincare products. It helps attract and retain moisture while improving product texture and stability.
It's important to consider that their environmental impact depends on factors such as their environmental concentration, persistence, and potential for bioaccumulation.
Generally speaking, these synthetic compounds are biodegradable to varying extents, as they can be broken down by microorganisms or through natural processes over time. These are not liquid microplastics, but their association with the petrochemical industry puts them on our "avoid" list.
Downsides of Humectants in Skincare
Humectants, as a group, are essential for skincare, and there is no specific downside to using them. They are the key factor in skin hydration.
As individual ingredients, the downsides or disadvantages would be unique to the user. Allergies, easy irritation, intolerance of hydroxy acids, etc., are all examples. Additionally, if you live in an arid climate with high heat and low humidity, following the proper steps above are essential to avoid having skin dryness worsen with humectant use (they're still important, you just have to use them properly).
It's always a good idea to discuss your routine with your dermatologist, especially if you have specific allergies or skin conditions like eczema. The benefits of humectants can still be important, but focusing on occlusive in some situations is more important for healing the skin barrier.
How to Shop for the Right Products
When shopping for a humectant-containing product for your skincare routine, consider your skin type, personal preferences, and whether you prefer an all-in-one product or a tailored multi-step routine. The sky's the limit with personal care products.
Understanding whether you have dry, oily, combination, or sensitive skin can guide you in selecting the most suitable humectant-containing product.
Most skincare regimens need some layering and steps to them. If you're trying for an all-in-one approach, you'll need to find a cream or lotion that contains both humectants and emollients. Very dry skin will usually need an occlusive moisturizer, while oily skin types can avoid the occlusives. It's important to know that acne-prone skin isn't always oily and dryness could in fact, be part of the problem.
This is why we prefer the layering approach and having more than one step. One step deals with hydration specifically, and one step deals with moisturization (remember: humectants focus on water (hydration) and lipids (fat/oils) focus on moisturization). This is the approach we prefer because you can choose your favourite humectants in a hydration serum, and then you can seal in all the moisture with your favourite oil serum as an emollient with active ingredients. This approach enables you to layer and adjust products according to your skin's needs and specific concerns, such as sensitivity, acne, or signs of aging.
How to Properly Use a Humectant Serum
If you've elected to go with a hydration serum that is humectant-only and contains no other emollients or occlusives, the following steps are quite important. The reason is that getting your skin hydrated (and keeping it hydrated) has to involve more than just water.
- cleanse, but do not fully dry the skin
- apply humectant serum
- lock it in with a second product that is either an emollient or an emollient/occlusive (usually heavier for dry skin). This is where face oils come in and work their magic
Humectants are an essential part of skin hydration. It doesn't matter what form you use them in (toner, serum, lotion, cream); what matters is that they're a part of your routine. They provide hydration and help keep skin looking healthy and youthful. There are many types of humectants so it's easy for people to find a combination that matches their skin type and concerns.
To get the most out of humectants, it's important to understand what type works best for you - as well as how to properly incorporate them into your routine. They need to be paired up with emollients and/or occlusives so they can stay where they're supposed to and do their important job.