Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

L'Oréal Professionnel Absolut Repair Protein Treatment Hair Mask Versus Shiseido Tsubaki Premium Repair Conditioner

L'Oréal Professionnel Absolut Repair Protein Treatment Hair Mask Versus Shiseido Tsubaki Premium Repair Conditioner What's inside Key Ingredients No key ingredients Benefits Concerns Ingredients Side-by-side Water Cetearyl Alcohol Behentrimonium Chloride Eupho

L'Oréal Professionnel Absolut Repair Protein Treatment Hair Mask Versus Shiseido Tsubaki Premium Repair Conditioner

What's inside

Key Ingredients

No key ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Cetearyl Alcohol

Behentrimonium Chloride

Euphorbia Cerifera Cera

Amodimethicone

Cetyl Esters

Isopropyl Alcohol

Glycerin

Phenoxyethanol

Trideceth-6

Linalool

Lactic Acid

Hexyl Cinnamal

Chlorhexidine Digluconate

Cetrimonium Chloride

Limonene

Sodium Hydroxide

Chenopodium Quinoa Seed Extract

Hydroxypropyltrimonium Hydrolyzed Wheat Protein

CI 19140

CI 15985

Parfum

Water, Cetearyl Alcohol, Behentrimonium Chloride, Euphorbia Cerifera Cera, Amodimethicone, Cetyl Esters, Isopropyl Alcohol, Glycerin, Phenoxyethanol, Trideceth-6, Linalool, Lactic Acid, Hexyl Cinnamal, Chlorhexidine Digluconate, Cetrimonium Chloride, Limonene, Sodium Hydroxide, Chenopodium Quinoa Seed Extract, Hydroxypropyltrimonium Hydrolyzed Wheat Protein, CI 19140, CI 15985, Parfum

Isopentyldiol

Stearyl Alcohol

Dimethicone

Behenyl Alcohol

Cetyl Alcohol

Dipropylene Glycol

Isopropyl Myristate

PEG-2 Laurate

Sodium Benzoate

Sodium Methyltaurate

Salicylic Acid

Aminopropyl Dimethicone

PPG-2-Deceth-12

Butylphenyl Methylpropional

Steartrimonium Chloride

Hydrogenated Polyisobutene

Polysilicone-13

Disodium EDTA

Phytosteryl/Octyldodecyl Lauroyl Glutamate

Camellia Japonica Seed Oil

Sodium Dilauramidoglutamide Lysine

Butylene Glycol

CI 17200

Royal Jelly Extract

Glycine Soja Seed Extract

Tocopherol

Water, Isopentyldiol, Behentrimonium Chloride, Glycerin, Stearyl Alcohol, Dimethicone, Behenyl Alcohol, Cetyl Alcohol, Isopropyl Alcohol, Parfum, Dipropylene Glycol, Isopropyl Myristate, PEG-2 Laurate, Sodium Benzoate, Phenoxyethanol, Amodimethicone, Sodium Methyltaurate, Salicylic Acid, Aminopropyl Dimethicone, PPG-2-Deceth-12, Butylphenyl Methylpropional, Steartrimonium Chloride, Hydrogenated Polyisobutene, Linalool, Polysilicone-13, Disodium EDTA, Phytosteryl/Octyldodecyl Lauroyl Glutamate, Camellia Japonica Seed Oil, Lactic Acid, Sodium Dilauramidoglutamide Lysine, Cetrimonium Chloride, Butylene Glycol, CI 19140, CI 17200, Royal Jelly Extract, Glycine Soja Seed Extract, Tocopherol

Reviews

Alternatives

Ingredients Explained

These ingredients are found in both products.

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

This water-soluble silicone is used for its hydrating and softening properties. It is used to add a silky feel to skincare products and has great benefits for haircare.

In haircare, this ingredient:

Adds shine

Protects color

Offers thermal protection

Boosts hair strength

Does not build up as easily

This ingredient is a preservative and often used for it's anti-static properties. You'll most likely see this ingredient in hair conditioners.

It does not cause irritation or sensitization in leave-on products at 1-5%.

This ingredient is a preservative, antimicrobial, and emulsifier. It is often used in cosmetics for its ability to cleanse, condition, and reduce static.

Cetrimonium chloride is a quaternary ammonium salt, meaning it has a water-soluble structure.

CI 19140 is also known as Tartrazine. Tartrazine is a synthetic dye used in cosmetics, foods, and medicine to add a yellow color.

Tartrazine is created from petroleum and is water-soluble.

Some people may experience allergies from this dye, especially asthmatics and those with an aspirin intolerance.

Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.

Topically, glycerin does several things at once:

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.

Isopropyl Alcohol is more commonly known as rubbing alcohol. It is most commonly used as a solvent, meaning it helps other ingredients dissolve.

This ingredient is an astringent alcohol. Astringent alcohols may also irritate skin as they high amounts may strip away your skin's natural oils.

Other types of astringent alcohols include:

According to the National Rosacea Society based in the US, you should be mindful of products with these alcohols in the top half of ingredients.

Any type of sanitizing product will have high amounts of alcohol to help kill bacteria and viruses.

Lactic Acid is another well-loved alpha hydroxy acid (AHA). It is gentler than glycolic acid but still highly effective.

Its main role is to exfoliate the surface of the skin by loosening the “glue” that holds dead skin cells together. Shedding those old cells leads to smoother, softer, and more even-toned skin.

Because lactic acid molecules are larger than glycolic acid, they don’t penetrate as deeply. This means they’re less likely to sting or irritate, making it a great choice for beginners or those with sensitive skin.

Like glycolic acid, it can:

Lactic acid also acts as a humectant (like hyaluronic acid). It can draw water into the skin to improve hydration and also plays a role in the skin's natural moisturizing factor (NMF) in the form of sodium lactate.

Studies show it can boost ceramide production to strengthen the skin barrier and even help balance the skin’s microbiome.

To get results, choose products with a pH between 3-4.

Lower strengths (5-12%) focus on surface exfoliation; higher strengths (12% and up) can reach deeper in the dermis (deeper, supportive layer) to improve skin texture and firmness over time.

Though it was originally derived from milk, most modern lactic acid used in skincare is vegan. It is made through non-dairy fermentation to create a bio-identical and stable form suitable for all formulations.

When lactic acid shows up near the end of an ingredient list, it usually means the brand added just a tiny amount to adjust the product’s pH.

Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.

Lactic acid is truly a gentle multitasker: it exfoliates, hydrates, strengthens, and brightens. It's a great ingredient for giving your skin a smooth, glowing, and healthy look without the harshness of stronger acids.

Read more about some other popular AHA's here:

Linalool is a fragrance and helps add scent to products. It's derived from common plants such as cinnamon, mint, citrus, and lavender.

Like Limonene, this ingredient oxidizes when exposed to air. Oxidized linalool can cause allergies and skin sensitivity.

This ingredient has a scent that is floral, spicy tropical, and citrus-like.

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.

Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).

It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.

On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.

Another perk of this ingredient is that it stays functional across a wide pH range (3-10).

You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.

Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.

Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.

Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.

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!

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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 Explained

  1. 01These ingredients are found in both products.
  2. 02Ingredients higher up in an ingredient list are typically present in a larger amount.
  3. 03This water-soluble silicone is used for its hydrating and softening properties. It is used to add a silky feel to skincare products and has great benefits for haircare.
  4. 04In haircare, this ingredient:
  5. 05Adds shine
  6. 06Protects color
  7. 07Offers thermal protection
  8. 08Boosts hair strength
  9. 09Does not build up as easily
  10. 10This ingredient is a preservative and often used for it's anti-static properties. You'll most likely see this ingredient in hair conditioners.
  11. 11It does not cause irritation or sensitization in leave-on products at 1-5%.
  12. 12Cetearyl alcohol is a waxy mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is an emollient and emulsifier.
  13. 13Despite having "alcohol" in its name, it has nothing to do with drying solvent alcohols; the FDA also allows "alcohol-free" products to contain fatty alcohols like this ingredient.
  14. 14It plays several roles in a formula:
  15. 15Typical use levels for this ingredient sit around 1-10% and the Cosmetic Ingredient Review Expert Panel has affirmed safety at concentrations up to 25% in leave-on products.
  16. 16Multiple assessments have found it to be non-irritating and non-sensitizing to most people.
  17. 17However, there have been some cases of allergic contact dermatitis in patients with chronically compromised skin barriers.
  18. 18Cetearyl alcohol has a comedogenic rating of 2 and irritancy rating of 1. Both of these numbers come from the 1989 study that used rabbit ears; a "2" means mildly comedogenic and a "1" means low irritancy.
  19. 19Here's the catch: rabbit skin is more sensitive than human skin and throws a lot of false positives. A 1996 reappraisal found that ingredients rated 1-2 in the rabbit ear tests are generally safe for humans.
  20. 20Remember comedogenic ratings are unable to assess the entire formula of a product or how it will react on your skin. Just be sure to patch test if you are unsure about certain ingredients.
Source · skinsort.com
02

Product index

Related product references

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Comparison edit

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