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Nutrition guide

K18 Hair Leave-In Molecular Repair Hair Mask Versus Elizavecca Cer-100 Collagen Coating Hair A+ Muscle Curl Cream

K18 Hair Leave-In Molecular Repair Hair Mask Versus Elizavecca Cer-100 Collagen Coating Hair A+ Muscle Curl Cream What's inside Key Ingredients No key ingredients Benefits Concerns Ingredients Side-by-side Water Alcohol Denat. Propylene Glycol Cetearyl Alcohol

K18 Hair Leave-In Molecular Repair Hair Mask Versus Elizavecca Cer-100 Collagen Coating Hair A+ Muscle Curl Cream

What's inside

Key Ingredients

No key ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Alcohol Denat.

Propylene Glycol

Cetearyl Alcohol

Dicaprylyl Ether

Cetyl Esters

Behentrimonium Chloride

Polysorbate 20

Sh-Oligopeptide-78

Hydrolyzed Wheat Protein

Hydrolyzed Wheat Starch

Isopropyl Alcohol

Tocopherol

Phenoxyethanol

Potassium Sorbate

Citric Acid

Parfum

Geraniol

Linalool

Hexyl Cinnamal

Benzyl Alcohol

Water, Alcohol Denat., Propylene Glycol, Cetearyl Alcohol, Dicaprylyl Ether, Cetyl Esters, Behentrimonium Chloride, Polysorbate 20, Sh-Oligopeptide-78, Hydrolyzed Wheat Protein, Hydrolyzed Wheat Starch, Isopropyl Alcohol, Tocopherol, Phenoxyethanol, Potassium Sorbate, Citric Acid, Parfum, Geraniol, Linalool, Hexyl Cinnamal, Benzyl Alcohol

Cyclopentasiloxane

Dimethicone

Glycerin

Pvp

Polyacrylamide

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

C13-14 Isoparaffin

Tromethamine

1,2-Hexanediol

Caprylyl Glycol

Butylene Glycol

Laureth-7

Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Isohexadecane

Illicium Verum Fruit Extract

Polysorbate 80

Disodium EDTA

Oenothera Biennis Oil

Argania Spinosa Kernel Oil

Chamomilla Recutita Flower Oil

Sorbitan Oleate

Cyclomethicone

Hydrolyzed Collagen

Gelatin

Hydrolyzed Keratin

Avena Sativa Protein Extract

Rosmarinus Officinalis Leaf Extract

Lavandula Angustifolia Flower Extract

Thymus Vulgaris Flower/Leaf/Stem Extract

Origanum Vulgare Extract

Hydrolyzed Corn Protein

Hydrolyzed Soy Protein

Water, Propylene Glycol, Cyclopentasiloxane, Dimethicone, Glycerin, Pvp, Polyacrylamide, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Parfum, C13-14 Isoparaffin, Tromethamine, 1,2-Hexanediol, Caprylyl Glycol, Butylene Glycol, Laureth-7, Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Isohexadecane, Illicium Verum Fruit Extract, Phenoxyethanol, Polysorbate 80, Disodium EDTA, Oenothera Biennis Oil, Argania Spinosa Kernel Oil, Chamomilla Recutita Flower Oil, Sorbitan Oleate, Cyclomethicone, Hydrolyzed Collagen, Gelatin, Hydrolyzed Keratin, Avena Sativa Protein Extract, Rosmarinus Officinalis Leaf Extract, Lavandula Angustifolia Flower Extract, Thymus Vulgaris Flower/Leaf/Stem Extract, Origanum Vulgare Extract, Hydrolyzed Corn Protein, Hydrolyzed Wheat Protein, Hydrolyzed Soy Protein

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 ingredient is a plant-derived protein made by breaking down wheat proteins into smaller amino acids and peptides. It has skin and hair conditioning properties.

People with known wheat allergy or a history of immediate reactions should be cautious with leave-on products containing hydrolyzed wheat proteins.

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.

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

SUPPLEMENTAL FIELD FILE

Notes to carry forward.

Source-derived references linked through this guide’s public topic markers.

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REFERENCE CARDS

Ingredients, lists & structured values

INGREDIENT LIST

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%.
  • Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
  • Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
  • Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.
  • Cetearyl alcohol is a waxy mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is an emollient and emulsifier.
  • Despite 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.
  • It plays several roles in a formula:
  • Typical 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.
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PROVISION SHELF

Products & side-by-side records