Thalgo Hydrating Cooling Gel-Cream

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

This ingredient gets a bad rep because it is irritating and drying due to its astringent property. Astringents draw out natural oils in tissue to constrict pores and dry out your skin.

However, alcohol denat. is not all that bad.

Due to its low molecular weight, alcohol denat. tends to evaporate quickly. One study on pig skin found half of applied alcohol evaporated in 10 seconds and less than 3% stayed on skin.

This also helps other ingredients become better absorbed upon application.

Studies are conflicted about whether this ingredient causes skin dehydration. One study from 2005 found adding emollients to propanol-based sanitizer decreased skin dryness and irritation. Another study found irritation only occurs if your skin is already damaged.

Small amounts of alcohol are generally tolerated by oily skin or people who live in humid environments.

The rule of thumb is this ingredient will probably not affect your skin much if it is near the end of an ingredients list.

One thing to note:
People with ALDH2 (aldehyde dehydrogenase 2) deficiency may experience skin irritation from continued alcohol use. About 8% of the world's population have this deficiency.

The Cosmetic Ingredient Review Expert Panel has determined denatured alcohols to be safe for use in concentrations between 0.05% and 12% (depending on which denaturant is used).

Also...

This ingredient has antimicrobial and solvent properties.

The antimicrobial property helps preserve products and increase their shelf life. As a solvent, it helps dissolve other ingredients.

Look for formulas that contain glycerin, hyaluronic acid, or panthenol if you want to offset any drying effect.

This ingredient will trip away your skin's natural oils/lipids that help it lock in moisture. This can worsen dryness, trigger eczema flare-ups, and aggravate rosacea.

Be sure to patch test any product with this ingredient if you have dry or sensitive skin, eczema, or rosacea.

You'll likely see this in many BHA products because this is the go-to solvent for salicylic acid.

This ingredient is typically used at levels between 2-20%.

Regarding fungal acne:
In 2019, this ingredient was tested against multiple Malassezia species (the yeast that causes fungal acne) and showed no growth.

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.

For instance, Habanolide is a proprietary trade name for a specific aroma chemical. When used as a fragrance ingredient in cosmetics, most aroma chemicals fall under the broad labeling category of “FRAGRANCE” or “PARFUM” according to EU and US regulations.

The term 'parfum' or 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term.

For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance by INCI standards.

One example is Calendula flower extract. Calendula is an essential oil that still imparts a scent or 'fragrance'.

Depending on the blend, the ingredients in the mixture can cause allergies and sensitivities on the skin. Some ingredients that are known EU allergens include linalool and citronellol.

Parfum can also be used to mask or cover an unpleasant scent.

The bottom line is: not all fragrances/parfum/ingredients are created equally. If you are worried about fragrances, we recommend taking a closer look at an ingredient. And of course, we always recommend speaking with a professional.

This ingredient is most commonly found in a popular trio called Aquaxyl. Aquaxyl is made up of anhydroxylitol(24 - 34%), xylitylglucoside (35 - 50%), and xylitol (5 - 15%).

According to a manufacturer, Aquaxyl is known for a 3-D hydration concept and an anti-dehydration shield to reinforce the outer layer of skin.

The Cosmetic Ingredient Review (CIR) Expert Panel evaluated it (along with 22 other acryloyldimethyltaurate polymers) and concluded it's:

Due to its large molecular size, it sits on the surface of skin rather than penetrating it.

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.

Aloe Barbadensis Leaf Juice also contains sugars. These sugars come in the form of monosaccharides and polysaccharides, folic acid, and choline. These sugars are able to help bind moisture to skin.

It also contains minerals such as calcium, 12 anthraquinones, fatty acids, amino acids, and Vitamin B12.

This ingredient is most commonly found in a popular trio called Aquaxyl. Aquaxyl is made up of anhydroxylitol (24 - 34%), xylitylglucoside (35 - 50%), and xylitol (5 - 15%).

According to a manufacturer, Aquaxyl is known for a 3-D hydration concept and an anti-dehydration shield to reinforce the outer layer of skin.

This ingredient is often derived from plants such as wood and sugarcane.

Due to its antioxidant properties, trehalose may help with signs of aging. Antioxidants help fight free-radical molecules, unstable molecules that may damage your skin.

In medicine, trehalose and hyaluronic acid are used to help treat dry eyes.

Some animals, plants, and bacteria create trehalose as a source of energy to survive freeze or lack of water.

Urea has the strongest exfoliation effect in concentrations higher than 10%. It is a keratolytic agent, meaning it breaks down the keratin protein in the top layer of skin. This helps remove dead skin cells and flaking skin.

In medicine, urea has been shown to help increase the potency of other ingredients, such as fungal treatments.

Humans and animals use urea to metabolize nitrogen-containing compounds. Urea is highly soluble in water. Once dissolved, it is neither acidic nor alkaline.

Urea is actually one of the more well-studied and well-supported ingredients out there if you have eczema.

Clinical trials have shown that urea creams in the 5 - 10% range can:

Higher concentrations (20 -30%) can also help with thickened, scaly patches but is also more likely to sting on active flares.

Skip urea if you have rosacea. The AAD (American Academy of Dermatology) lists it alongside alcohol, menthol, and fragrance as a potential irritant for rosacea-prone skin. Urea's keratolytic and penetration-enhancing properties can trigger stinging, burning, and redness.

As always, your skin is unique, so definitely check in with your dermatologist.

The prebiotic property of xylitol may also help reinforce our skin's natural microbiome. Having a healthy microbiome prevents infection by bad bacteria and helps with hydration.

As a humectant, Xylitol helps draw moisture from both the air and from deeper skin layers. This helps keep skin hydrated.

Xylitol is a sugar alcohol and commonly used as a sugar substitute. It is naturally occurring in plants such as strawberries and pumpkin.

Due to this ingredient having a similar composition to cetearyl alcohol, this ingredient may not be malassezia folliculitis safe. However, the risk is low and has been only shown by a single study, so SkinSort does not currently flag C14-22 Alcohols as a fungal acne trigger.

Research on a hydrogel with serine confirmed this serine got delivered to your stratum corneum and demonstrated enhanced skin moisturization.

Interestingly serine also helps your skin produce filaggrin, a protein that keeps your skin barrier strong and used to create collagen.

Studies show this ingredient may be an effective wrinkle reducer as it can deeply penetrate into skin. It has also been show to help with wound healing.

Beyond hydration, Biosaccharide Gum-1 gives formulas a silky, non-sticky feel.

This ingredient is gentle, versatile, and suitable for all skin types.

Fun fact: Similar sugars can be found naturally in fruits like apples and pears.

Fucus Vesiculosus Extract contains antioxidants. Antioxidants help fight free-radicals. Free-radicals are molecules that may damage your skin cells, such as pollution.

Fucus Vesiculosus Extract is also rich in sodium, potassium, and amino acids.

Many different types of algae have different benefits.

This ingredient is rich in amino acids, proteins, sugars, and vitamins. Small amounts of minerals such as phosphorous, iron, potassium, and copper are also found the seaweed.

These components help hydrate and nourish your skin's natural barrier. Having a healthy skin barrier leads to more youthful looking skin and may help reduce the signs of aging.

Laminaria Digitata is found in the northern Atlantic Ocean.

What's the difference between algae and seaweed?
Algae is a broad term that includes seaweed. Not all algae is seaweed.

This property also makes Pentylene Glycol a great texture enhancer. It can also help thicken or stabilize a product.

Pentylene Glycol also acts as a mild preservative and helps to keep a product microbe-free.

Some people may experience mild eye and skin irritation from Pentylene Glycol. We always recommend speaking with a professional about using this ingredient in your routine.

Pentylene Glycol has a low molecular weight and is part of the 1,2-glycol family.

In its pure form, Benzoic Acid looks like a white crystalline solid. It has slight solubility in water.

The name of Benzoic Acid comes from gum benzoin, which used to be the sole source of deriving this ingredient. Benzoic Acid is the most simple aromatic carboxylic acid.

Benzoic Acid is naturally occuring in strawberries, mustard, cinnamon, and cloves. It has a slight scent but is not considered to be a fragrance.

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.

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

Chelating agents help neutralize unwanted metals from affecting the formulation.

Sodium gluconate is water-soluble.

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.

It's worth knowing sugars are already a natural component of the skin's NMF (natural moisturizing factor) so it's a molecule that your stratum corneum is well-acquainted with.

Just so you know, glucose is hydrophilic (water-loving) and the stratum corneum is a strong barrier to hydrophilic compounds. This just means penetration is slow and most of the action is happening on the surface.

Gram-to-gram, glucose is not as efficient as a humectant as glycerin. This is why you'll likely see glycose paired with stronger humectants for a bigger hydration payoff.

In skincare, glucose is typically derived from corn or other starch sources.

Another benefit is a bit of UV protection. Vitamin E helps reduce the damage caused by UVB rays. (It should not replace your sunscreen). Combining it with Vitamin C can decrease sunburned cells and hyperpigmentation after UV exposure.

You might have noticed Vitamin E + C often paired together. This is because it is great at stabilizing Vitamin C. Using the two together helps increase the effectiveness of both ingredients.

There are often claims that Vitamin E can reduce/prevent scarring, but these claims haven't been confirmed by scientific research.

As an emollient, the fatty acids in soybean oil helps keep your skin soft and hydrated. It does so by creating a film on top that traps moisture in.

Soybean oil is also rich in vitamin E, a potent antioxidant. Vitamin E is also anti-inflammatory and provides a soothing effect.

Studies show soy may help fade hyperpigmentation from UVB. It does so by disrupting the melanin process from UVB induced skin inflammation.

This ingredient may not be malassezia folliculitis, or fungal-acne, safe.

Soybeans are rich in proteins and are part of the legume family. Foods made with soybeans include tofu, soymilk, edamame, miso, and soy sauce.

However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.

Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.

In skincare formulas, citric acid can:

While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.

Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations.

Read more about some other popular AHA's here:

This ingredient is derived from isobutane. It is the simplest form of a tertiary alcohol. Due to its chemical structure, it is more resistant to oxidation.

Some sources online claim T-Butyl Alcohol is a fatty alcohol. However, it is not considered one due to its chemical structure.

Potassium Sorbate, another commonly-used preservative, is the potassium salt of Sorbic Acid.

Sorbic Acid may worsen eczema. We recommend speaking with a professional if you have any concerns.

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

Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.

Due to it being edible and tasteless, you'll likely find this ingredient in breath freshener strips. This ingredient is produced from the starch of the fungus, Aureobasidium pullulans.

Pullulan is stable over a broad-range of pH.