Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Eskinol Spot-Less Glow Facial Deep Cleanser Versus PCA Skin Nutrient Toner

Eskinol Spot-Less Glow Facial Deep Cleanser Versus PCA Skin Nutrient Toner This brightening toner is formulated around Sodium Ascorbyl Phosphate and Citric Acid to brighten dull-looking skin and refine skin texture. This smoothing toner is formulated around La

Eskinol Spot-Less Glow Facial Deep Cleanser Versus PCA Skin Nutrient Toner

This brightening toner is formulated around Sodium Ascorbyl Phosphate and Citric Acid to brighten dull-looking skin and refine skin texture.

This smoothing toner is formulated around Lactic Acid and Gluconic Acid to refine skin texture and brighten dull-looking skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Alcohol Denat.

Citric Acid

Sodium Citrate

PEG-40 Hydrogenated Castor Oil

Parfum

Citrus Junos Callus Extract

Propylene Glycol

Sodium Ascorbyl Phosphate

Menthol

CI 47005

Water, Alcohol Denat., Citric Acid, Sodium Citrate, PEG-40 Hydrogenated Castor Oil, Parfum, Citrus Junos Callus Extract, Propylene Glycol, Sodium Ascorbyl Phosphate, Menthol, CI 47005

Sucrose

Cucurbita Pepo

Lactic Acid

Octoxynol-9

Gluconic Acid

Yeast

Guanidine Hcl

Cinnamomum Cassia Leaf Oil

Eugenia Caryophyllus Leaf Oil

Glutathione

Zingiber Officinale Root Oil

Zinc Salicylate

Aspergillus/Molasses Ferment Filtrate

Glycerin

Potassium Chloride

Benzyl Benzoate

Eugenol

Coumarin

Cinnamal

Isoeugenol

Cinnamyl Alcohol

Water, Sucrose, Cucurbita Pepo, Propylene Glycol, Lactic Acid, Citric Acid, Octoxynol-9, Parfum, Gluconic Acid, Yeast, Guanidine Hcl, Cinnamomum Cassia Leaf Oil, Eugenia Caryophyllus Leaf Oil, Glutathione, Zingiber Officinale Root Oil, Alcohol Denat., Zinc Salicylate, Aspergillus/Molasses Ferment Filtrate, Glycerin, Potassium Chloride, Benzyl Benzoate, Eugenol, Coumarin, Cinnamal, Isoeugenol, Cinnamyl Alcohol

Alternatives

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Alcohol Denat. is an alcohol with a denaturant property. It is created by mixing ethanol with other additives.

The "denat" part just means "denatured"; common denaturants include Denatonium Benzoate, t-butyl alcohol, and Diethyl Phthalate. This step makes the alcohol undrinkable (and lets brand skip taxes related to beverage alcohol).

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.

Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.

Like other AHAs, citric acid can exfoliate skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath.

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.

Rosacea skin has a lower threshold for acids generally, with 62.5% of rosacea subjects in one study reacting to lactic acid in a sting test. This is why we mark citric acid as a potential rosacea trigger.

However, this ingredient shows up as a pH adjuster or chelator at roughly 0.1-1% in many products. These low levels are unlikely to be an issue for rosacea skin and becomes a potential trigger at exfoliating concentrations (20%). Because everybody's skin is unique, we recommend a patch test if you are unsure.

Parfum is a catch-all term for an ingredient or more that is used to give a scent to products.

Also called "fragrance", this ingredient can be a blend of hundreds of chemicals or plant oils. This means every product with "fragrance" or "parfum" in the ingredients list is a different mixture.

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.

Propylene Glycol is a synthetic, colorless, odorless liquid that has been a staple in cosmetics for decades. It is a skin conditioning agent, humectant, and solvent.

As a humectant, it draw water to the skin to reduce flaking and restore suppleness. It's also a solvent that helps dissolve other actives and keeps formulas stable across temperature changes.

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!

Similar Comparisons

The reference edit

Ingredients, questions
& further reading.

Connected source records selected through this article’s public topic index.

01

Formula cabinet

Ingredients & structured notes

Ingredient index

Ingredients Side-by-side

  1. 01Water
  2. 02Caprylic/Capric Triglyceride
  3. 03Glycerin
  4. 04Glyceryl Stearate
  5. 05Aloe Barbadensis Leaf Juice
  6. 06Sodium Hyaluronate
  7. 07Cucumis Sativus Fruit Extract
  8. 08Chamomilla Recutita Flower Extract
  9. 09Potassium Cetyl Phosphate
  10. 10Butyrospermum Parkii Butter
  11. 11Tocopherol
  12. 12Ethylhexylglycerin
  13. 13Xanthan Gum
  14. 14Carbomer
  15. 15Phenoxyethanol
  16. 16Sodium Hydroxide
  17. 17Water, Caprylic/Capric Triglyceride, Glycerin, Glyceryl Stearate, Aloe Barbadensis Leaf Juice, Sodium Hyaluronate, Cucumis Sativus Fruit Extract, Chamomilla Recutita Flower Extract, Potassium Cetyl Phosphate, Butyrospermum Parkii Butter, Tocopherol,…
  18. 18C12-15 Alkyl Benzoate
  19. 19Cetearyl Alcohol
  20. 20Isopropyl Palmitate
Source · skinsort.com
02

Product index

Related product references

Product

PCA Skin Hydrating Mask

PCA Skin Hydrating Mask PCA Skin Hydrating Mask ingredients explained: Water, Glycerin, Avena Sativa (Oat) Kernel Extract, Glycine Soja (Soybean) Oil, Carthamus Tinctorius (Safflower) Seed …

Source: incidecoder.comView reference →

Product

PCA Skin Hydramatte

PCA Skin Hydramatte PCA Skin Hydramatte ingredients explained: Water, Dimethicone, Glycerin, C12-15 Alkyl Lactate, Sodium Polyacrylate, Butylene Glycol, Hydrogenated Polydecene, Phenoxyetha…

Source: incidecoder.comView reference →

Product

PCA Skin C-Quench Antioxidant Serum

PCA Skin C-Quench Antioxidant Serum PCA Skin C-Quench Antioxidant Serum ingredients explained: Water/Aqua/Eau, Hamamelis Virginiana (Witch Hazel) Water, Ascorbic Acid, Alcohol, Hydroxyethyl…

Source: incidecoder.comView reference →
03

Comparison edit

Read side by side