Amika Normcore Signature Shampoo Versus K18 Hair PEPTIDE PREP™ pH Maintenance Shampoo

Amika Normcore Signature Shampoo Versus K18 Hair PEPTIDE PREP™ pH Maintenance Shampoo

What's inside

Key Ingredients

No key ingredients

Benefits

No benefits

Concerns

Ingredients Side-by-side

Water

Sodium Cocoyl Isethionate

Glycol Distearate

Cocamidopropyl Hydroxysultaine

Cocamidopropylamine Oxide

Hippophae Rhamnoides Fruit/Seed Oil

Coconut Acid

Sodium Isethionate

PEG-150 Distearate

Caprylyl Glycol

Guar Hydroxypropyltrimonium Chloride

Ethylhexylglycerin

Hexylene Glycol

Citric Acid

Sodium Chloride

Polyquaternium-7

Cocamidopropyl Betaine

Phenoxyethanol

Parfum

Benzyl Benzoate

Hydroxycitronellal

Limonene

Water, Sodium Cocoyl Isethionate, Glycol Distearate, Cocamidopropyl Hydroxysultaine, Cocamidopropylamine Oxide, Hippophae Rhamnoides Fruit/Seed Oil, Coconut Acid, Sodium Isethionate, PEG-150 Distearate, Caprylyl Glycol, Guar Hydroxypropyltrimonium Chloride, Ethylhexylglycerin, Hexylene Glycol, Citric Acid, Sodium Chloride, Polyquaternium-7, Cocamidopropyl Betaine, Phenoxyethanol, Parfum, Benzyl Benzoate, Hydroxycitronellal, Limonene

Sodium C14-16 Olefin Sulfonate

Sodium Methyl 2-Sulfolaurate

Sodium Lauryl Sulfoacetate

Sh-Oligopeptide-78

Panthenol

Glycerin

Sodium Phytate

Disodium 2-Sulfolaurate

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

Alternatives

Ingredients Explained

These ingredients are found in both products.

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

Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.

Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.

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

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.

Cocamidopropyl Betaine is a fatty acid created by mixing similar compounds in coconut oil and dimethylaminopropylamine, a compound with two amino groups.

This ingredient is a surfactant and cleanser. It helps gather the dirt, pollutants, and other impurities in your skin to be washed away. It also helps thicken a product and make the texture more creamy.

Being created from coconut oil means Cocamidopropyl Betaine is hydrating for the skin.

While Cocamidopropyl Betaine was believed to be an allergen, a study from 2012 disproved this. It found two compounds in unpure Cocamidopropyl Betaine to be the irritants: aminoamide and 3-dimethylaminopropylamine. High-grade and pure Cocamidopropyl Betaine did not induce allergic reactions during this study.

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.

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.

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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