Updated on August 09, 2023
Overview
What they are
These products are both cruelty-free and reef safe serums. They have a total of 11 ingredients in common
Cool Features
They both contain hyaluronic acid, niacinamide and peptides
Suited For
They're both likely to be good for fighting acne, anti aging, dry skin, brightening skin, oily skin, reducing pores, scar healing and dark spots
Free From
They both do not contain any parabens or sulfates
What's Inside
They both contain fragrances and oils
We independently verify ingredients, and our claims are backed by peer-reviewed research. Spot a product that needs an update? Let us know.
Ingredient Info
COSRX The 6 Peptide Skin Booster Serum 44 ingredients
Numbuzin No.9 Secret Firming Serum 37 ingredients
At a glance
Click on any of the items below to learn more
COSRX The 6 Peptide Skin Booster Serum 44 ingredients
Numbuzin No.9 Secret Firming Serum 37 ingredients
Notable Ingredients
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Benefits
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Concerns
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Notable Ingredients
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Benefits
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Ingredients Side-by-side
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.
Dipropylene Glycol is a synthetically created stabilizer and solvent. It is a part of the glycol class in the alcohol family.
Glycerin is already naturally found in your skin. It helps moisturize and protect your skin.
Pentylene glycol is typically used within a product to thicken it. It also adds a smooth, soft, and moisturizing feel to the product. It is naturally found in plants such as sugar beets.
1,2-Hexanediol is a multi-tasker ingredient. It acts as a preservative to increase shelf-life and can aid other preservatives in preventing microbe growth. 1,2-Hexanediol also helps the skin retain moisture as a humectant.
6 Benefits
Niacinamide has emerged as an all-star ingredient due to its many benefits.
Acetyl Hexapeptide-8 is a peptide. A common name for this peptide is Argireline.
Helps with Anti-Aging
Copper Tripeptide-1 is a peptide naturally found in body fluids. Peptides are building blocks for protein.
Not safe for Fungal Acne
Palmitoyl Tripeptide-8 isn't fungal acne safe and is a peptide.
Allantoin plays a role in soothing and moisturizing the skin. Because of this, it is often added to products with strong active ingredients.
Sodium Hyaluronate is hyaluronic acid's salt form. It is commonly derived from the sodium salt of hyaluronic acid.
Acetyl Glucosamine is an antioxidant and humectant. It is a form of Vitamin C.
Serine is an amino acid naturally found in our body. Our bodies use amino acids to create protein.
Glycine is an amino acid that helps build proteins. It is already present in our skin as our bodies produce them naturally.
Threonine is an amino-acid. It helps hydrate the skin and has antioxidant benefits.
Arginine is an amino acid that is important for human development. Your body uses is it to produce hair keratin and skin collagen.
Proline is an amino-acid. It helps moisturize the skin and plays an important role in creating proteins.
Betaine is a common humectant (a substance that promotes retention of moisture). It's known to be gentle on the skin and can help balance hydration.
Sodium PCA is the sodium salt of pyroglutamic acid and is naturally occurring on human skin.
Sodium Lactate is the sodium salt of lactic acid, an AHA. It is a humectant and used to adjust the pH of a product.
Glutamic Acid is an amino acid that is found in all living organisms. Our bodies use this to help nerve cells in the brain communicate with other cells.
Antioxidant 4 Benefits May cause irritation
Tocopherol (also known as Vitamin E) is a common antioxidant used to help protect the skin from free-radicals and strengthen the skin barrier. It's also fat soluble - this means our skin is great at absorbing it.
Not safe for Fungal Acne
Glycine Soja Oil comes from the soybean. Glycine Soja is native to eastern Asia.
Hydrogenated Lecithin is created from the hydrogenation of lecithin. Hydrogenation is a chemical reaction between molecule hydrogen and another element.
Ammonium Acryloyldimethyltaurate/Vp Copolymer (let's call it AAVC for short) is a synthetically created polymer. It's used as a film-forming agent and used to thicken the consistency of products.
Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.
Ethylhexylglycerin (we can't pronounce this either) is commonly used as a preservative and skin softener. It is derived from glyceryl.
Adenosine is in every living organism. It is one of four components in nucleic acids that helps store our DNA.
Polyquaternium-51 is a polymer salt. It helps hydrate the skin by creating a film on top. This film traps moisture in, keeping your skin soft and hydrated.
Disodium EDTA plays a role in making products more stable by aiding other preservatives.
4 Benefits 2 Concerns
Citric Acid is an AHA derived from citrus fruits (think oranges, lemons, and limes!).
Caprylyl Glycol is a humectant and emollient, meaning it attracts and preserves moisture.
Fragrance
T-Butyl Alcohol it is most commonly used as a solvent.
Potassium Sorbate is a preservative used to prevent yeast and mold in products. It is commonly found in both cosmetic and food products.
Water, Dipropylene Glycol, Glycerin, Pentylene Glycol, 1,2-Hexanediol, Niacinamide, Acetyl Hexapeptide-8, Copper Tripeptide-1, Sh-Polypeptide-121, Dipeptide Diaminobutyroyl Benzylamide Diacetate, Oligopeptide-68, Palmitoyl Tripeptide-8, Allantoin, Sodium Hyaluronate, Acetyl Glucosamine, Serine, Alanine, Glycine, Threonine, Arginine, Proline, Betaine, Sodium PCA, Sodium Lactate, PCA, Glutamic Acid, Lysine Hcl, Tocopherol, Dextran, Glycine Soja Oil, Hydrogenated Lecithin, Ammonium Acryloyldimethyltaurate/Vp Copolymer, Polyacrylate Crosspolymer-6, Butylene Glycol, Xanthan Gum, Ethylhexylglycerin, Adenosine, Polyquaternium-51, Disodium EDTA, Citric Acid, Caprylyl Glycol, T-Butyl Alcohol, Potassium Sorbate, Sodium Oleate
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.
Glycerin is already naturally found in your skin. It helps moisturize and protect your skin.
Hydrogenated Polydecene is an emollient. It creates a non-occlusive film on the skin that offers extra protection for your skin barrier.
Propanediol helps absorb ingredients into your skin, boosting their benefits. It can act as an emollient, making your skin softer. Propanediol can help products last longer by boosting the properties of preservatives within the formulation.
Pentaerythrityl Tetraethylhexanoate is an emollient. Emollients help your skin stay soft and smooth by creating a thin film on top. This film helps trap moisture. It also helps improve the texture of products by adding thickness or helping to create a silky feel.
6 Benefits
Niacinamide has emerged as an all-star ingredient due to its many benefits.
Dimethicone is a silicone used for making products smooth and silky. It also has the added benefit of sealing in hydration. The amount of dimethicone found in beauty products is considered safe and non-comedogenic, meaning it won't clog pores.
Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
2 Concerns
Butyrospermum Parkii Butter is a plant lipid from the fruit of the Shea Tree. It is an effective skin hydrator and emollient.
2 Concerns
Hydrogenated Vegetable Oil is created by adding hydrogen to vegetable oil in order to give it more stability. This process also raises the melting point of vegetable oil. In cosmetics, it is an emollient.
Hydrolyzed Hyaluronic Acid is a form of hyaluronic acid. It is created by the hydrolysis of hyaluronic acid with a high molecular weight. Once created, Hydrolyzed Hyaluronic Acid has a low molecular weight.
Not safe for Fungal Acne
Palmitoyl Tripeptide-5 isn't fungal acne safe and is a peptide.
Acetyl Hexapeptide-8 is a peptide. A common name for this peptide is Argireline.
EU Allergen
Lavandula Angustifolia Oil is more commonly known as lavender essential oil. Lavandula Angustifolia is known as the English Lavender and famous for creating purple fields in Provence, France.
Citrus Aurantium Dulcis Peel Oil is oil from the peel of an orange fruit.
Rosmarinus Officinalis Leaf Oil is oil expressed from the leaves of the rosemary plant.
Oil EU Allergen
This ingredient comes from the bark of the Cedarwood tree.
Adenosine is in every living organism. It is one of four components in nucleic acids that helps store our DNA.
Glyceryl Stearate Citrate is a citric acid ester of glyceryl stearate.
Polyglyceryl-3 Methylglucose Distearate is created from the diester of stearic acid and the condensation product of methylglucose and Polyglycerin-3.
Glyceryl Stearate is a mix of glycerin and stearic acid.
3 Concerns
Cetearyl alcohol is a mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is mainly used as an emulsifier. Emulsifiers help prevent the separation of oils and products. Due to its composition, it can also be used to thicken a product or help create foam.
Palmitic Acid is a fatty acid found in our skin. In cosmetics, it is usually derived from palm oil. It is a cleanser, emollient, and emulsifier.
Stearic Acid is a fatty acid. It is an emollient, emulsifier, and texture enhancer.
Dimethicone/Vinyl Dimethicone Crosspolymer is a silicone used to improve the texture of products and absorb oil. It does not get absorbed into the skin.
Glyceryl Caprylate comes from glycerin and caprylic acid, a fatty acid from coconut.
Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.
Caprylyl Glycol is a humectant and emollient, meaning it attracts and preserves moisture.
1,2-Hexanediol is a multi-tasker ingredient. It acts as a preservative to increase shelf-life and can aid other preservatives in preventing microbe growth. 1,2-Hexanediol also helps the skin retain moisture as a humectant.
Ethylhexylglycerin (we can't pronounce this either) is commonly used as a preservative and skin softener. It is derived from glyceryl.
Disodium EDTA plays a role in making products more stable by aiding other preservatives.
Carbomer is a polymer of acrylic acid. Its main role is to create gel consistency within products.
Tromethamine is an aliphatic compound. An aliphatic compound is an organic compound with open-chained carbon atoms. It is synthetically created. Tromethamine is used to balance pH and improve texture.
2 Concerns
Linalool is a fragrance and helps add scent to products. It's derived from common plants such as cinnamon, mint, citrus, and lavender.
Limonene is a fragrance that adds scent and taste to a formulation.
Water, Glycerin, Hydrogenated Polydecene, Propanediol, Pentaerythrityl Tetraethylhexanoate, Niacinamide, Dimethicone, Butylene Glycol, Butyrospermum Parkii Butter, Hydrogenated Vegetable Oil, Hydroxypropyltrimonium Hyaluronate, Hydrolyzed Hyaluronic Acid, Palmitoyl Tripeptide-5, Acetyl Hexapeptide-8, Lavandula Angustifolia Oil, Citrus Aurantium Dulcis Peel Oil, Rosmarinus Officinalis Leaf Oil, Cedrus Atlantica Bark Oil, Adenosine, Glyceryl Stearate Citrate, Polyglyceryl-3 Methylglucose Distearate, Glyceryl Stearate, Cetearyl Alcohol, Palmitic Acid, Stearic Acid, Dimethicone/Vinyl Dimethicone Crosspolymer, Glyceryl Caprylate, Sodium Polyacrylate, Xanthan Gum, Caprylyl Glycol, 1,2-Hexanediol, Ethylhexylglycerin, Disodium EDTA, Carbomer, Tromethamine, Linalool, Limonene
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
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. Stay hydrated!
Learn more about WaterGlycerin is already naturally found in your skin. It helps moisturize and protect your skin.
A study from 2016 found glycerin to be more effective as a humectant than AHAs and hyaluronic acid.
As a humectant, it helps the skin stay hydrated by pulling moisture to your skin. The low molecular weight of glycerin allows it to pull moisture into the deeper layers of your skin.
Hydrated skin improves your skin barrier; Your skin barrier helps protect against irritants and bacteria.
Glycerin has also been found to have antimicrobial and antiviral properties. Due to these properties, glycerin is often used in wound and burn treatments.
In cosmetics, glycerin is usually derived from plants such as soybean or palm. However, it can also be sourced from animals, such as tallow or animal fat.
This ingredient is organic, colorless, odorless, and non-toxic.
Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
Learn more about Glycerin1,2-Hexanediol is a multi-tasker ingredient. It acts as a preservative to increase shelf-life and can aid other preservatives in preventing microbe growth. 1,2-Hexanediol also helps the skin retain moisture as a humectant.
In products that are water-based, this ingredient can help stabilize perfumes and fragrances. It can also help make the texture of products softer and more smooth.
Niacinamide has emerged as an all-star ingredient due to its many benefits.
It is known to treat acne by reducing inflammation. It also helps fade dark-spots and strengthen the skin by promoting the growth of the ceramide barrier.
Other benefits include smoothing wrinkles and minimizing redness.
The cherry on top? Niacinamide can also help build keratin, a protein that keeps skin firm.
When incorporating niacinamide into your routine, look out for concentration amounts. Typically, 5% niacinamide provides benefits such as fading dark spots. However, if you have sensitive skin, it is better to begin with a smaller concentration.
Niacinamide can be mixed with other ingredients to boost benefits. For instance, it has shown to be effective when used with copper, folic acid, and zinc to treat acne.
Learn more about NiacinamideAcetyl Hexapeptide-8 is a peptide. A common name for this peptide is Argireline.
Argireline has a similar function to botox. It prevents muscle movement and contractions. By preventing muscles from moving, Argireline also prohibits the formation of fine lines and wrinkles. However, research is lacking in proving this ingredient to be as effective as botox.
Argireline tells our body to create more collagen. Collagen is a protein that makes connective tissue. Boosting collagen production leads to a healthier skin barrier. Having a healthy skin barrier means having firm and hydrated skin.
Read more about other common types of peptides here:
Learn more about Acetyl Hexapeptide-8Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
- It is a solvent, meaning that it helps to dissolve other ingredients. This also enhances the absorption of the product into one's skin.
- It is a humectant, which means that it helps attract moisture into the skin.
- It helps improve product application.
Overall, Butylene Glycol is a safe and well-rounded ingredient. It is unlikely to irritate skin, and works well with pretty much all other ingredients.
Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.
On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.
Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.
Learn more about Xanthan GumEthylhexylglycerin (we can't pronounce this either) is commonly used as a preservative and skin softener. It is derived from glyceryl.
You might see Ethylhexylglycerin often paired with other preservatives such as phenoxyethanol. Ethylhexylglycerin has been found to increase the effectiveness of these other preservatives.
Adenosine is in every living organism. It is one of four components in nucleic acids that helps store our DNA.
Adenosine has many benefits when used. These benefits include hydrating the skin, smoothing skin, and reducing wrinkles. Once applied, adenosine increases collagen production. It also helps with improving firmness and tissue repair.
Studies have found adenosine may also help with wound healing.
In skincare products, Adenosine is usually derived from yeast.
Learn more about AdenosineDisodium EDTA plays a role in making products more stable by aiding other preservatives.
It is a chelating agent, meaning it neutralizes metal ions that may be found in a product.
Disodium EDTA is a salt of edetic acid and is found to be safe in cosmetic ingredients.
Learn more about Disodium EDTACaprylyl Glycol is a humectant and emollient, meaning it attracts and preserves moisture.
It is a common ingredient in many products, especially those designed to hydrate skin. The primary benefits are retaining moisture, skin softening, and promoting a healthy skin barrier.
Though Caprylyl Glycol is an alcohol derived from fatty acids, it is not the kind that can dry out skin.
This ingredient is also used as a preservative to extend the life of products. It has slight antimicrobial properties.
Learn more about Caprylyl GlycolIngredient Ratings
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When to use
COSRX The 6 Peptide Skin Booster Serum 44 ingredients
Numbuzin No.9 Secret Firming Serum 37 ingredients
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