Fourth Ray Beauty Soak It Up Hydrating Mask

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

This is due to how structurally similar it is to what your skin already produces.

Though it is mostly an emollient that helps soften and hydrate skin, it also has some humectant and occlusive action. Humectants help the skin retain moisture while occlusives seal it in, making squalane a triple-threat moisturizer.

Research shows it has antioxidant capabilities that help protect against stressors like UV exposure, specifically UVA induced oxidative stress. This study also found that it supports collagen biosynthesis in human dermal fibroblasts.

No clinical study has reported significant adverse effects and irritation reactions are very rare from this ingredient (even at 100% concentration).

Overall, it's a fantastic ingredient for hydration and is suitable for all skin types.

This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.

Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.

Read more about squalene with an "e".

Though squalane is often called an oil, it’s technically not one. It is a hydrocarbon, meaning it is only made of carbon and hydrogen. True oils are triglycerides and made of fatty acids and glycerol.

The term “oil-free” isn’t regulated so companies can define it however they want. Some exclude all oils, while others just avoid mineral oil or comedogenic oils.

Squalane has a comedogenic rating of 1 from the original 1972 study that tested raw ingredients under occlusion on rabbit ears. This system is not standardized or peer-reviewed, and using the raw ingredients is very different from how diluted cosmetic formulations are used on human skin.

A comedogenic rating of 1 means it is "unlikely to clog pores" according to the original rating system.

The overall formula of a product matters more than the individual ingredients on whether or not it will cause clogged pores.

Two clinical studies in postmenopausal women found that applying argan oil for 60 days significantly improved skin elasticity and moisturization (reduced transepidermal water loss and increased epidermal water content).

Since it is high in oleic and linoleic acid, this ingredient may not be fungal acne safe. Both of these fall in the C11-C24 range that Malassezia yeast can metabolize.

In vitro research found an increase in skin hydration by 58% and a decrease in TEWL by 37.8% after 24 hours of applying this ingredient (pretty impressive for a single ingredient!).

Besides hydration, shea butter also contains triterpenes that have anti-inflammatory potential. In particule, lupeol cinnamate has shown the highest anti-inflammatory activity in vivo.

Shea butter also contains vitamins A and E which may contribute to antioxidant activity.

While Shea Butter has an SPF rating of about 3-4, it is not a sunscreen replacement.

This ingredient may not be fungal acne safe because its fatty acids fall within the C11-C24 range that the Malassezia yeast can metabolize.

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

These fatty acids are very similar to those naturally found in the epidermis, making this oil biomimetic; basically, your skin recognizes it.

Clinical testing found this ingredient to be moisturizing and non-irritating, with noteworthy effects on reducing transepidermal water loss (TEWL).

Besides fatty acids, marula oil is also rich in oxidative stabilizers like vitamin E, vitamin C precursors, and polyphenols. This gives it excellent shelf stability compared to most facial oils.

This is a great ingredient for dry, dull, or barrier-compromised skin.

Just know it may not be fungal acne safe due to the oleic and palmitic acid content. These fatty acids can as as a food source for the Malassezia yeast.

Emollients help keep your skin soft and hydrated by creating a film that traps moisture in.

In 2000, Behenyl Alcohol was approved by the US as medicine to reduce the duration of cold sores.

This ingredient is typically used in concentrations between 1-10%. Studies have found it to be non-sensitizing, non-phototoxic, and non-photoallergenic.

A close cousin of this ingredient is Glyceryl Stearate SE ("self-emulsifying"). This just has a small amount of sodium or potassium stearate added so it can emulsify without a co-emulsifier.

Since this ingredient is an ester of a C18 fatty acid, it may not be fungal acne safe. The Malassezia yeast can potentially metabolize within the C11-C24 range.

Fun fact: The human body also creates Glyceryl Stearate naturally.

Fatty alcohols are usually derived from natural fats and oils and therefore do not have the same drying or irritating effect as solvent (ethanol) alcohols.

The FDA allows products labeled "alcohol-free" to have fatty alcohols.

This ingredient may not be fungal acne safe. It is a primary fatty alcohol with a chain length above 12 carbons. A study from 2019 show Malassezia can feed on fatty alcohols in this range, so it may trigger fungal acne in those prone to it.

Aloe leaves are also great moisturizers. They are naturally rich in polysaccharides, a carbohydrate made of sugars. Polysaccharides are able to mimic the carbs found in the top layer of your skin. This can help keep your skin hydrated.

Aloe contains the antioxidants Vitamins A, C, and E. These vitamins neutralize free radicals. Free-radicals are molecules that may damage your skin cells, such as pollution.

Aloe does not protect against UV rays, despite it soothing sunburns.

The cellulose and fiber in colloidal oatmeal help reduce inflammation. This can also help the skin feel softer.

Colloidal Oatmeal is also an antioxidant. Antioxidants protect our skin from free-radical damage.

Oatmeal also contains beneficial compounds:

This ingredient is created by mixing grounded oatmeal and a liquid base.

The fatty acids found in sunflowers include (from highest amount to least): linoleic acid, myristic acid, palmitic acid, stearic acid, arachidic acid, oleic acid, and linolenic acid.

These fatty acids hydrate your skin. Emollients create a film on the skin to prevent moisture from escaping.

These compounds protect your skin two ways:

1) They fight off free radicals, or the unstable molecules from things like sun and pollution that age and damage skin.
2) They help calm inflammation by switching off the chemical signals that tell skin to get red and irritated.

Lab studies also suggest that rosmarinic acid may help protect collagen and slow sugar-related damage to it.

The Cosmetic Ingredient Review has concluded rosemary-derived ingredients to be safe when formulated to be non-sensitizing.

Rosemary can occasionally cause allergic contact dermatitis (due to carnosol), so be sure to patch test if you have reactive or fragrance-sensitive skin.

Oryza Sativa Bran Extract contains numerous antioxidants such as ferulic acid. Antioxidants help fight free-radical molecules. Free-radical molecules are capable of damaging our cells and other genetic material.

They contain shikimate dehydrigenase, an enzyme shown to help reduce inflammation and soothe the skin.

The amino acids found in cucumbers help nourish our skin's natural acid mantle (it's an important part of our skin barrier). This slightly acidic film acts as a barrier to protect us from bacteria, viruses, and other contaminants.

Unless you have an allergy to cucumbers, this is generally a non-irritating ingredient.

Fun fact: Cucumis Sativus is native to South Asia and can now be found on every continent.

Research shows it can encourage your skin cells to turn over and renew by stimulating keratinocyte and fibroblast proliferation.

It also has mild keratolytic properties to help loosen and shed dead skin cells without being harsh.

Studies also suggest allantoin can help calm inflammation by dialing down some of the chemical signals your skin sends out when it is irritated.

This ingredient is typically used in the 0.1-0.5% range, and the FDA recognizes it as a skin protectant in OTC products up to 2%.

Overall, allantoin is a wonderful addition to most routines; it is stable across a wide pH range (~4-8), works well with other ingredients, and is considered non-sensitizing/non-irritating.

Fun fact: Allantoin is naturally occurring in comfrey root, beets, chamomile, and wheat sprouts. Our bodies even produce it as a byproduct of uric acid metabolism.

Though it has "alcohol" in the name, it is not related to denatured alcohol or ethyl alcohol.

The FDA allows products labeled "alcohol-free" to have fatty alcohols.

This ingredient may not be fungal acne safe. It is a primary fatty alcohol with a chain length above 12 carbons. A study from 2019 show Malassezia can feed on fatty alcohols in this range, so it may trigger fungal acne in those prone to it.

They work by fitting perfectly into your stratum corneum's lipid matrix since they're structurally similar to cholesterol. Here, they reinforce your skin's barrier.

One small in vivo human study showed topical soybean phytosterols sped up barrier recovery within three days on tape-stripped skin.

Broader research credits them with:

Formulation use typically sit under 5%.

Testing in soy-allergic subjects found no sensitization signals, but be sure to patch test if you are unsure or have existing allergies.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

This ingredient is an emollient, emulsifier, and penetration enhancer. As an emollient, it helps soften and hydrate skin by trapping moisture within. As an emulsifier, it prevents oil and water ingredients from separating.

Hydrogenated Lecithin can form tiny spherical structures made of phospholipid bilayers called liposomes. These liposomes are able to capture compounds inside their structure and deliver them through the skin barrier.

Because phospholipids are a natural component of our cell membranes, this ingredient is inherently compatible with skin.

A 2021 study found lecithin-based surfactants were less harsh and more tolerable comared to Sodium Lauryl Sulfate (SLS).

Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

D-panthenol is also known as dexpanthenol. Most cosmetics use dexpanthenol or a mixture of D and L-panthenol.

Panthenol is famous due to its ability to go deeper into the skin's layers. Using this ingredient has numerous pros (and no cons):

Like hyaluronic acid, panthenol is a humectant. Humectants are able to bind and hold large amounts of water to keep skin hydrated.

This ingredient works well for wound healing. It works by increasing tissue in the wound and helps close open wounds.

Once oxidized, panthenol converts to pantothenic acid. Panthothenic acid is found in all living cells.

This ingredient is also referred to as pro-vitamin B5.

On top of that, soybean oil is rich in vitamins like vitamin E, a potent antioxidant.

Research on soybean's active components also point to anti-inflammatory, collagen-stimulating, antioxidant activity, and protection against UV-induced oxidative damage.

Most of this research applies to the broader soybean plant and not just the oil fraction alone.

This ingredient may not be fungal acne safe due to the oleic acid content.

Your body uses linoleic acid to build ceramides and prostaglandins. Ceramides keep your skin's barrier hydrated and strong while prosaglandins help control inflammation and healing.

Needless to say, linoleic acid is crucial for having a strong skin barrier.

One study found applying linoleic acid rich sunflower oil to be more effective at repairing the skin barrier than olive oil.

This ingredient can also help treat acne by softening sebum to prevent clogged pores. Another study found using 2.5% linoleic acid gel for 4 weeks showed a 25% reduction in small comedones.

Studies show it can also help lighten hyperpigmentation or sun spots by disrupting the melanin production process. It also helps your skin shed melanin pigment from your skin caused by UV exposure.

Due to its role in the production of the fatty acid prostaglandin, linoleic acid can also help reduce inflammation and support wound healing.

Fun fact: Linoleic acid is an essential fatty acid. This means our bodies cannot create it on its own and we need to get it through foods such as nuts and vegetable oils.

Just know this ingredient is not always fungal-acne safe because it is a long-chain fatty acid (with 18 carbon atoms) that directly feeds the Malassezia yeast responsible for fungal acne.

Because they mirror the lipids naturally found in the deeper layers of your skin, topical phospholipids help reinforce the lipid matrix, reduce transepidermal water loss, and leave skin feeling conditioned.

They're also used to form liposomes, or tiny self-assembling vesible used to stabilize actives like vitamin c or retinol. This helps these ingredients integrate into the upper layers of skin more easily.

Phospholipids are compatible with everything and the CIR Expert Panel has concluded them to be safe at current use levels.

Some types of phospholipids include:

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

As a humectant, it pulls water into the skin. But it's a pretty minor moisturizing ingredient compared to other humectants, like glycerin.

Interestingly, it can act as a mild penetration enhancer. One in vitro study on human skin found a 12% concentration upped the absorption of mometasone furoate (a medicinal ingredient used to treat inflammatory skin conditions) up to 7%.

This ingredient is typically used at levels of 0.1-10% depending on the role it's playing.

A patch test study on eczema patients didn't find a significant increase in irritation versus the control group, but the potential for irritation rises at higher concentrations.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

As a polysaccharide, Maltodextrin has moisturizing properties. Polysaccharides are a type of carbohydrate. The top layer of skin uses polysaccharides to retain water, keeping the skin hydrated.

Maltodextrin is water soluble and has a sweet taste.

Both potassium sorbate and sorbic acid can be found in baked goods, cheeses, dried meats, dried fruit, ice cream, pickles, wine, yogurt, and more.

You'll often find this ingredient used with other preservatives.

The way it works is worth understanding; benzoic acid works when the formula is acidic. It is able to sneak into a microbe's cell and mess up how it functions to stop it from growing in an acidic product.

However, the acid switches to an inactive form and stops working if a product isn't acidic enough (above ~5 pH). This is why you'll often see it in low pH products or teamed up with other preservatives to cover the gap.

Safety wise, it's one of the better studied preservatives out there.

The Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe for use in cosmetic formulations at concentrations up to 5%.

A large international review found this ingredient had no effects on the human body and had low irritation potential.

Just so you know, real world use is usually much lower than the 5% ceiling (usually 1% of less).

The EU caps it at 2.5% in rinse-off products, 1.7% in oral care, and 0.5% in leave-on products.

One thing worth mentioning (it's nothing to worry about): some people get a little stinging or flushing where they apply it. This isn't a true allergy; it's a temporary and harmless reaction. This is the same kind of mild tingle you might notice from sorbic acid.

It is effective at low concentrations (<0.6%). Clinical studies have found it to be non-irritating, non-sensitizing, and non-photosensitizing.