Olaplex No.4 Bond Maintenance Shampoo Versus K18 Hair PEPTIDE PREP™ pH Maintenance Shampoo

Olaplex No.4 Bond Maintenance Shampoo Versus K18 Hair PEPTIDE PREP™ pH Maintenance Shampoo

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Sodium Lauroyl Methyl Isethionate

Cocamidopropyl Hydroxysultaine

Potassium Cocoyl Glycinate

Disodium Cocoyl Glutamate

Potassium Cocoate

Sodium Lauroyl Sarcosinate

Glycereth-26

Decyl Glucoside

Parfum

Phenoxyethanol

Cocamidopropylamine Oxide

Sodium Cocoyl Glutamate

Glycol Distearate

Disodium Laureth Sulfosuccinate

Methyl Gluceth-20

Acrylates Copolymer

PEG-120 Methyl Glucose Dioleate

Amodimethicone

Polyquaternium-10

Citric Acid

Ethylhexylglycerin

Sodium Lauryl Sulfoacetate

Divinyldimethicone/Dimethicone Copolymer

Chlorphenesin

Polyquaternium-11

Guar Hydroxypropyltrimonium Chloride

C11-15 Pareth-7

Trisodium Ethylenediamine Disuccinate

Laureth-9

Glycerin

Trideceth-12

Panthenol

Hydrolyzed Vegetable Protein Pg-Propyl Silanetriol

C12-13 Pareth-3

C12-13 Pareth-23

Helianthus Annuus Seed Oil

Tocopherol

Pseudozyma Epicola/Camellia Sinensis Seed Oil Ferment Extract Filtrate

Pseudozyma Epicola/Argania Spinosa Kernel Oil Ferment Filtrate

Prunus Armeniaca Kernel Oil

Quaternium-95

Propanediol

Helianthus Annuus Seed Extract

PEG-8

Bis-Aminopropyl Diglycol Dimaleate

Euterpe Oleracea Fruit Extract

Rosmarinus Officinalis Leaf Extract

Punica Granatum Extract

Origanum Vulgare Leaf Extract

Musa Sapientum Fruit Extract

Morinda Citrifolia Fruit Extract

Sodium Hyaluronate

PEG-8/Smdi Copolymer

Arctium Lappa Root Extract

Sodium Polyacrylate

Palmitoyl Myristyl Serinate

Citral

Hexyl Cinnamal

Limonene

Biotin

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate

Water, Sodium Lauroyl Methyl Isethionate, Cocamidopropyl Hydroxysultaine, Potassium Cocoyl Glycinate, Disodium Cocoyl Glutamate, Potassium Cocoate, Sodium Lauroyl Sarcosinate, Glycereth-26, Decyl Glucoside, Parfum, Phenoxyethanol, Cocamidopropylamine Oxide, Sodium Cocoyl Glutamate, Glycol Distearate, Disodium Laureth Sulfosuccinate, Methyl Gluceth-20, Acrylates Copolymer, PEG-120 Methyl Glucose Dioleate, Amodimethicone, Polyquaternium-10, Citric Acid, Ethylhexylglycerin, Sodium Lauryl Sulfoacetate, Divinyldimethicone/Dimethicone Copolymer, Chlorphenesin, Polyquaternium-11, Guar Hydroxypropyltrimonium Chloride, C11-15 Pareth-7, Trisodium Ethylenediamine Disuccinate, Laureth-9, Glycerin, Trideceth-12, Panthenol, Hydrolyzed Vegetable Protein Pg-Propyl Silanetriol, C12-13 Pareth-3, C12-13 Pareth-23, Helianthus Annuus Seed Oil, Tocopherol, Pseudozyma Epicola/Camellia Sinensis Seed Oil Ferment Extract Filtrate, Pseudozyma Epicola/Argania Spinosa Kernel Oil Ferment Filtrate, Prunus Armeniaca Kernel Oil, Quaternium-95, Propanediol, Helianthus Annuus Seed Extract, PEG-8, Bis-Aminopropyl Diglycol Dimaleate, Euterpe Oleracea Fruit Extract, Rosmarinus Officinalis Leaf Extract, Punica Granatum Extract, Origanum Vulgare Leaf Extract, Musa Sapientum Fruit Extract, Morinda Citrifolia Fruit Extract, Sodium Hyaluronate, PEG-8/Smdi Copolymer, Arctium Lappa Root Extract, Sodium Polyacrylate, Palmitoyl Myristyl Serinate, Citral, Hexyl Cinnamal, Limonene, Biotin, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate

Sodium C14-16 Olefin Sulfonate

Cocamidopropyl Betaine

Sodium Methyl 2-Sulfolaurate

Sh-Oligopeptide-78

Sodium Phytate

Disodium 2-Sulfolaurate

Caprylyl Glycol

Caprylhydroxamic Acid

Benzoic Acid

Sodium Hydroxide

Water, Sodium C14-16 Olefin Sulfonate, Cocamidopropyl Betaine, Sodium Methyl 2-Sulfolaurate, Sodium Lauryl Sulfoacetate, Sh-Oligopeptide-78, Panthenol, Glycerin, Sodium Phytate, Guar Hydroxypropyltrimonium Chloride, Disodium 2-Sulfolaurate, Caprylyl Glycol, Caprylhydroxamic Acid, Benzoic Acid, Citric Acid, Sodium Hydroxide, Parfum, Limonene

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Alternatives

Ingredients Explained

These ingredients are found in both products.

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

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.

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.

This ingredient is derived from guar gum. It is a skin conditioning agent that creates a thin, breathable film to reduce water loss during cleansing.

This leaves the skin feeling soft rather than stripped and also contributes to a creamier lather.

Due to the large molecule size, this ingredient is unlikely to penetrate skin.

Limonene is a fragrance that adds scent and taste to a formulation.

It's found in the peel oil of citrus fruits and other plants such as lavender and eucalyptus. The scent of limonene is generally described as "sweet citrus".

Limonene acts as an antioxidant, meaning it helps neutralize free radicals.

When exposed to air, oxidized limonene may sensitize the skin. Because of this, limonene is often avoided by people with sensitive skin.

The term '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.

Panthenol is a common ingredient that helps hydrate and soothe the skin. It is found naturally in our skin and hair.

There are two forms of panthenol: D and L.

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.

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.

Sodium Lauryl Sulfoacetate is an organic salt with a naturally sweet odor. It is an alternative to traditional sulfates and is commonly found in "sulfate-free" products.

In cosmetics, this ingredient is used to increase the volume of foam, emulsify ingredients, and as a cleansing agent.

As a cleansing agent, sodium lauryl sulfoacetate helps reduce the surface tension of dirt, oil, and other pollutants so they can be rinsed away easily.

Cosmetic Ingredient Review found this ingredient to irritate the eyes and skin in concentrations of 0.18% and 0.7%.

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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