Serum
Serum
British United Kingdom
American United States

What's inside

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

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Ingredients Explained

These ingredients are found in both products.

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

Masking, Skin Conditioning

Alanine is an amino acid and is already found in the human body. Our skin uses alanine to build collagen, elastin, and keratin.

Masking, Skin Conditioning

Arginine is a semi-essential amino acid. This just means our bodies can product a bit on its own, but sometimes needs a little boost from food sources.

It is a part of your skin's natural moisturizing factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.

Here's an interesting thing about Arginine: your skin converts it into urea through the Krebs-Henseleit urea cycle. Urea is one of the most effective humectants your skin naturally produces.

A clinical study showed applying 2.5% arginine hydrochloride to atopic dermatitis skin showed significant urea levels in the stratum corneum and improved moisture in just four weeks.

Arginine is also a precursor to nitric oxide; nitric oxide improves microcirculation and supports wound healing and collagen synthesis.

One study found that an amino acid complex containing Arginine reduced skin irritation, improved hydration, and accelerated skin repair in clinical / in-vivo studies.

Arginine itself is an amino acid and not a fatty acid, oil, or ester. On its own, it's not a direct food source for Malassezia, or the yeast that causes fungal acne.

Learn more about Arginine
Masking, Skin Conditioning

Aspartic Acid is an amino acid that our bodies produce naturally. It is an antioxidant.

Our body uses Aspartic Acid to help build collagen and elastin. It also plays a role in hydrating skin.

Humectant, Masking, Skin Conditioning

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.

Learn more about Butylene Glycol
Skin Conditioning

Ceramide NP (formerly known as Ceramide 3) is one of the skin's naturally occurring lipids.

Since ceramides are the major lipid components of the skin, they are crucial for maintaining skin barrier and hydration. Ceramide NP most closely mirrors the dominant kind in human skin amongst ceramide subtypes.

This ceramide works by slotting into gaps within the stratum corneum's lipid matrix to limit trans-epidermal water loss (TEWL) and shield the skin against external irritants.

A study with 312 patients found that using a ceramide-containing routine for 4 weeks reduced the severity of atopic dermatitis by over 61%.

Another clinical study in subjects aged 60 and older found that a ceramide body wash and moisturizer improved skin dryness and itchy skin in 15 days.

Overall, ceramides are considered non-irritating and safety tests have found little to no observable adverse effects from using this ingredient.

Ceramide NP is usually sourced from plants (like soybean or rice bran), or produced synthetically.

Learn more about Ceramide NP
Humectant

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.

In cosmetics, glutamic acid is a famous humectant. It draws water from the air to your skin, keeping your skin hydrated (like hyaluronic acid).

An in-vitro study from 2024 found glutamic acid to play a role in inhibiting inflammation and thus a potential skin-soothing ingredient.

Other studies show it to be have potential wound healing, skin barrier repair, and hair growth properties.

Glutamic acid has poor solubility in water and other solvents.

Learn more about Glutamic Acid
Humectant, Skin Conditioning, Skin Protecting

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.

Learn more about Glycerin
Buffering, Skin Conditioning

Glycine is the smallest amino acid and a key building block of collagen. It's part if your skin's Natural Moisturizing Factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.

A study from 2022 found that an amino acid complex featuring taurine, arginine, and glycine significantly reduced skin irritation, improved redness, and accelerated the skin repair process.

Humectant, Skin Conditioning

Histidine is a semi-essential amino acid used by our bodies to create protein. It has humectant and skin conditioning properties.

Our bodies use histidine to create filaggrin - filaggrin is a structural protein that the skin uses in maintaining skin barrier.

One study found histidine and carnosine to be a dynamic duo for your skin:

Oral histidine has also been found to help with filaggrin-deficit skin disorders such as atopic dermatitis.

Why is it considered a semi-essential amino acid? This is because adults are able to create it but children must get it from their diet.

Learn more about Histidine
Skin Conditioning

Isoleucine is an amino acid that helps reinforce our skin barrier. This amino acid plays a role in creating protein for the body.

Fun fact: Isoleucine is found in meat, fish, dairy, legumes, and nuts.

Skin Conditioning

We don't have a description for Leucine yet.

Skin Conditioning

Lysine is an essential amino acid (your body cannot make it on its own). It has skin conditioning properties and one of the key players in collagen synthesis.

When your body creates collagen, lysine is basically the glue that holds everything together. It helps collagen fibers lock into each other and stay strong, with vitamin C being its trusty sidekick. Without enough lysine, this glue gets flimsy and less firm, resulting in less bouncy skin.

In skincare, lysine is mostly there to help keep your skin moisturized. It carries water through your skin's layers so everything stays plump.

So will putting lysine on your face create bouncier skin?

It's hard to say; most of the exciting collagen research on lysine comes from oral supplements or lab studies on mice. Further research is needed to truly understand what role topical lysine plays in skincare and your skin.

However, there's no harm in adding lysine to your routine as a supportive and hydrating ingredient.

Learn more about Lysine
Preservative

Phenoxyethanol is a preservative that has germicide, antimicrobial, and aromatic properties. Studies show that phenoxyethanol can prevent microbial growth. By itself, it has a scent that is similar to that of a rose.

It's often used in formulations along with Caprylyl Glycol to preserve the shelf life of products.

Masking, Skin Conditioning

Phenylalanine is an amino acid. It is a skin soothing and hydrating ingredient. Amino acids play a crucial role in wound healing and skin hydration.

This ingredient is also used to help even out skin tone due to its ability to disrupt the melanin production process.

Two structures of phenylalanine exist: L-phenylalanine and D-phenylalanine. L-phenylalanine is essential, this means our bodies cannot produce it naturally and we must get it from foods. Our bodies convert D-phenylalanine to neurotransmitters, and D-phenylalanine is found in our bodies naturally.

Some foods that contain L-phenylalanine include eggs, soybeans, beef, milk.

Learn more about Phenylalanine
Preservative

Potassium Sorbate is a preservative used to prevent yeast and mold in products. It is commonly found in both cosmetic and food products.

This ingredient comes from potassium salt derived from sorbic acid. Sorbic acid is a natural antibiotic and effective against fungus.

Both potassium sorbate and sorbic acid can be found in baked goods, cheeses, dried meats, dried fruit, ice cream, pickles, wine, yogurt, and more.

You'll often find this ingredient used with other preservatives.

Learn more about Potassium Sorbate
Skin Conditioning

Proline is a non-essential amino acid, meaning your body can make it on its own. In skincare, it is a skin conditioning ingredient that keeps skin soft and hydrated.

It makes up about 23% of the collagen molecule (collagen is the protein responsible for keeping your skin firm) and is involved in your skin's natural hyaluronic acid production. When applied topically, proline can penetrate the skin fairly well due to its small molecular size.

Reviews of this ingredient have found it to be neither a dermal irritant nor a sensitizer.

Fun fact: Proline can be found in protein-rich foods like meat, fish, eggs, and dairy.

Learn more about Proline
Masking, Skin Conditioning

Serine is a non-essential amino acid (your body makes it on its own!). It is a major player in your skin's natural moisturizing factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.

Serine is one of your NMF's most abundant components that works as a skin-identical humectant. Its hydroxyl group grabs onto water molecules to boost hydration without any heaviness or occlusion.

Research on a hydrogel with serine confirmed this serine got delivered to your stratum corneum and demonstrated enhanced skin moisturization.

Interestingly serine also helps your skin produce filaggrin, a protein that keeps your skin barrier strong and used to create collagen.

Learn more about Serine
Masking, Preservative

Sodium Benzoate is a preservative. It's used in both cosmetic and food products to inhibit the growth of mold and bacteria. It is typically produced synthetically.

Both the US FDA and EU Health Committee have approved the use of sodium benzoate. In the US, levels of 0.1% (of the total product) are allowed.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

Learn more about Sodium Benzoate

Threonine is an amino-acid. It helps hydrate the skin and has antioxidant benefits.

Our skin uses threonine for creating collagen and elastin. Humans are not able to create threonine and must get it through eating foods such as fish, lentils, poultry, sesame seeds, and more.

Antioxidant, Masking, Skin Conditioning

Tocopherol is a fat-soluble antioxidant known as Vitamin E.

You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

Learn more about Tocopherol
Masking, Skin Conditioning

Tyrosine is one of the amino acids used to create protein. It plays a role in melanin production.

A study from 2012 found tyrosine to show promising results in restoring skin volume.

Masking, Skin Conditioning

Valine is an essential amino acid. It is used by our bodies for tissue repair and muscle growth.

An essential amino acid is one in which our bodies cannot naturally produce so we must get them through diet. Foods such as eggs, dairy, red meat, and fish contain valine.

This ingredient can either be derived from an animal product or be synthetically created.

Learn more about Valine
Skin Conditioning, Solvent

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!

Learn more about Water

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