Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Beauty of Joseon Dynasty Cream (Old Formulation) Versus Saturday Skin Carrot + Niacinamide Moisturizing Cream

Beauty of Joseon Dynasty Cream (Old Formulation) Versus Saturday Skin Carrot + Niacinamide Moisturizing Cream This barrier-repair moisturizer is formulated around Niacinamide and Adenosine to strengthen the skin barrier and hydrate skin. This brightening moist

Beauty of Joseon Dynasty Cream (Old Formulation) Versus Saturday Skin Carrot + Niacinamide Moisturizing Cream

This barrier-repair moisturizer is formulated around Niacinamide and Adenosine to strengthen the skin barrier and hydrate skin.

This brightening moisturizer is formulated around Squalane and Niacinamide to brighten dull-looking skin and hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycerin

Butylene Glycol

Niacinamide

Dipentaerythrityl Hexa C5-9 Acid Esters

Sodium Hyaluronate

Xanthan Gum

Cyclopentasiloxane

Cyclohexasiloxane

Polyacrylate-13

Polyisobutene

Polysorbate 20

Hydrogenated Lecithin

C14-28 Alkyl Acid

Stearyl Alcohol

Behenyl Alcohol

Dimethicone/Vinyl Dimethicone Crosspolymer

Dimethicone

Adenosine

Glyceryl Stearate Se

Cetearyl Alcohol

Polyglyceryl-3 Methylglucose Distearate

Cetyl PEG/PPG-10/1 Dimethicone

Stearic Acid

Tocopheryl Acetate

Sodium Polyacrylate

Olea Europaea Fruit Oil

Helianthus Annuus Seed Oil

Centella Asiatica Extract

Hippophae Rhamnoides Oil

Argania Spinosa Kernel Oil

Butyrospermum Parkii Butter

Ceramide NP

Trehalose

Calendula Officinalis Flower Extract

Caprylhydroxamic Acid

1,2-Hexanediol

Raphanus Sativus Leaf Extract

Oryza Sativa Bran Extract

Cucurbitaceae Extract

Orchid Extract

Honey Extract

Panax Ginseng Root Extract

Carthamus Tinctorius Seed Oil

Phytosphingosine

Ceteareth-20

Glyceryl Citrate/Lactate/Linoleate/Oleate

Parfum

Water, Glycerin, Butylene Glycol, Niacinamide, Dipentaerythrityl Hexa C5-9 Acid Esters, Sodium Hyaluronate, Xanthan Gum, Cyclopentasiloxane, Cyclohexasiloxane, Polyacrylate-13, Polyisobutene, Polysorbate 20, Hydrogenated Lecithin, C14-28 Alkyl Acid, Stearyl Alcohol, Behenyl Alcohol, Dimethicone/Vinyl Dimethicone Crosspolymer, Dimethicone, Adenosine, Glyceryl Stearate Se, Cetearyl Alcohol, Polyglyceryl-3 Methylglucose Distearate, Cetyl PEG/PPG-10/1 Dimethicone, Stearic Acid, Tocopheryl Acetate, Sodium Polyacrylate, Olea Europaea Fruit Oil, Helianthus Annuus Seed Oil, Centella Asiatica Extract, Hippophae Rhamnoides Oil, Argania Spinosa Kernel Oil, Butyrospermum Parkii Butter, Ceramide NP, Trehalose, Calendula Officinalis Flower Extract, Caprylhydroxamic Acid, 1,2-Hexanediol, Raphanus Sativus Leaf Extract, Oryza Sativa Bran Extract, Cucurbitaceae Extract, Orchid Extract, Honey Extract, Panax Ginseng Root Extract, Carthamus Tinctorius Seed Oil, Phytosphingosine, Ceteareth-20, Glyceryl Citrate/Lactate/Linoleate/Oleate, Parfum

Squalane

Phytosteryl/Isostearyl/Cetyl/Stearyl/Behenyl Dimer Dilinoleate

Pentaerythrityl Tetraethylhexanoate

Pentylene Glycol

Polymethylsilsesquioxane

Dipentaerythrityl Hexahydroxystearate/Hexastearate/Hexarosinate

Hydrogenated Rapeseed Oil

PEG-60 Glyceryl Isostearate

PEG-32

PEG-6

Tranexamic Acid

Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Hydrogenated Vegetable Oil

Glyceryl Stearate

Hydroxyacetophenone

Isohexadecane

Hydrogenated Olive Oil

Copernicia Cerifera Wax

Polysorbate 80

Dipotassium Glycyrrhizate

Daucus Carota Sativa Root Extract

Sorbitan Oleate

Olea Europaea Oil Unsaponifiables

Eclipta Prostrata Extract

Eclipta Prostrata Leaf Extract

Daucus Carota Sativa Root Water

Moringa Oleifera Seed Oil

Panthenol

Glycine Max Oil

Cholesterol

PEG-800

Ginkgo Biloba Leaf Extract

Beta-Carotene

Tocopherol

Ethylhexylglycerin

Sh-Oligopeptide-1

Sh-Polypeptide-1

Sh-Oligopeptide-2

Sh-Polypeptide-22

Sh-Polypeptide-45

Sh-Polypeptide-8

Sh-Polypeptide-9

Water, Squalane, Glycerin, Niacinamide, Butylene Glycol, Phytosteryl/Isostearyl/Cetyl/Stearyl/Behenyl Dimer Dilinoleate, Adenosine, Behenyl Alcohol, Pentaerythrityl Tetraethylhexanoate, Pentylene Glycol, Polymethylsilsesquioxane, 1,2-Hexanediol, Dimethicone, Dipentaerythrityl Hexahydroxystearate/Hexastearate/Hexarosinate, Hydrogenated Rapeseed Oil, PEG-60 Glyceryl Isostearate, PEG-32, PEG-6, Tranexamic Acid, Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Hydrogenated Vegetable Oil, Glyceryl Stearate, Hydroxyacetophenone, Stearyl Alcohol, Isohexadecane, Hydrogenated Olive Oil, Copernicia Cerifera Wax, Polysorbate 80, Sodium Polyacrylate, Olea Europaea Fruit Oil, Dipotassium Glycyrrhizate, Daucus Carota Sativa Root Extract, Sorbitan Oleate, Olea Europaea Oil Unsaponifiables, Eclipta Prostrata Extract, Eclipta Prostrata Leaf Extract, Daucus Carota Sativa Root Water, Ceramide NP, Hydrogenated Lecithin, Moringa Oleifera Seed Oil, Panthenol, Glycine Max Oil, Cholesterol, PEG-800, Centella Asiatica Extract, Polysorbate 20, Ginkgo Biloba Leaf Extract, Beta-Carotene, Tocopherol, Ethylhexylglycerin, Sh-Oligopeptide-1, Sh-Polypeptide-1, Sh-Oligopeptide-2, Sh-Polypeptide-22, Sh-Polypeptide-45, Sh-Polypeptide-8, Sh-Polypeptide-9

Reviews

Be the first to review

Alternatives

Ingredients Explained

These ingredients are found in both products.

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

1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.

It is a:

Humectant, drawing moisture into the skin

Emollient, helping to soften skin

Solvent, dispersing and stabilizing formulas

Preservative booster, enhancing the antimicrobial activity of other preservatives

Adenosine is a purine nucleoside that your body already makes in every cell. In skincare, it acts mainly as a skin conditioning and anti-aging agent.

The way it works is fairly well mapped out:

Your skin has cells called fibroblasts that build collagen (the stuff that keeps skin firm and smooth). Adenosine basically flips a switch on these cells that tells them to get to work making more collagen and other proteins. These cells slow down on their own as skin ages, so Adenosine helps give them a little nudge to keep going.

The clinical backing is pretty solid too.

A blind, randomized, placebo-controlled trial of 126 women aged 45-65 tested a 0.1% cream twice daily and found real improvements in crow's feet and frown lines using a precise 3D skin-mapping technique; these changes showed up by week 3 and held at 2 months.

A later study using Adenosine-loaded dissolving microneedle patches reported gains in wrinkle depth, dermal density, elasticity, and hydration.

On concentrations, South Korea's Ministry of Food and Drug Safety has set 0.04% as the approved functional anti-wrinkle level. You'll typically see this ingredient used somewhere in the 0.04-0.1% range since it works at low doses.

This ingredient has been found safe for cosmetics with the data showing no irritation or sensitization.

Overall, this is a great ingredient for any anti-aging routine and has no photosensitizing effect, so it suits both AM and PM use.

Behenyl Alcohol is a type of fatty alcohol (these are different from the drying, solvent alcohols).

Fatty Alcohols have hydrating properties and are most often used as an emollient or to thicken a product. They are usually derived from natural fats and oils; behenyl alcohol is derived from the fats of vegetable oils.

Emollients help keep your skin soft and hydrated by creating a film that traps moisture in.

In 2000, Behenyl Alcohol was approved by the US as medicine to reduce the duration of cold sores.

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.

Centella Asiatica Extract (Centella) is one of the most researched botanical extracts in skincare with decades of studies backing its effects on inflammation, collagen, and the skin barrier.

That research keeps pointing back to the same four triterpenoid saponins: Asiaticoside, Madecassoside, Asiatic Acid, and Madecassic Acid.

These compounds allow centella to dial back inflammation, encourage the skin to build and hold onto collagen, support the barrier and hydration, and bring solid antioxidant activity to protect against signs of aging.

Centella also carries a nice supporting cast of Vitamin A, vitamin C, several B vitamins, and amino acids. Put it all together and you get an ingredient that soothes, hydrates, and protects, all at once.

Most of centella's magic comes from the four big compounds (Asiaticoside, Madecassoside, Asiatic Acid, and Madecassic Acid). These are the actives doing the heavy lifting in almost every centella study.

Here is the short version of what they do in the skin:

So it is not just soothing for the sake of soothing. Centella calms the skin AND helps it rebuild.

Just FYI, not all centella on an ingredient list is the same. What you are getting actually depends on the extract:

Fun fact on the ratios: the leaves tend to be richest in Madecassoside and Asiaticoside, and lower in the two acids. The exact amounts shift with where the plant is grown and how it is processed. This means purity really does vary brand to brand.

Centella is one of the most easygoing actives out there.

It layers well with basically everything: niacinamide, hyaluronic acid, peptides, and vitamin C, and also pairs nicely with stronger actives like retinoids and exfoliating acids where it can help take the edge off irritation.

On the safety side, centella and its triterpenes are classified as weak sensitizers, meaning allergic reactions are possible but uncommon.

Patch tests at 1% and 5% came back negative in test panels, and creams at typical use levels did not cause allergic reactions across large groups of people.

But as with any new active, a patch test is still a smart move for very reactive skin.

Centella is widely used because it is effective at low percentages. For context, human safety testing found no meaningful irritation from creams containing centella extract at everyday use levels (the tested amounts were well under 1%).

The irritancy threshold in animal testing was also above 30% (so real-world formulas sit far below anything concerning).

In collagen lab studies, higher concentrations drove more collagen synthesis, so serums built around centella tend to feature it more prominently.

Bottom line: you will find centella working nicely anywhere from a fraction of a percent up to hero-ingredient levels depending on whether it is a supporting soother or the main event.

Fun fact: Centella has been used as a medicine and in food for many centuries. As a medicine, it is used to treat burns, scratches, and wounds.

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.

Dimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.

What it does:

Dimethicone comes in different viscosities:

Depending on the viscosity, dimethicone has different properties.

Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.

This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.

Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.

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.

Hydrogenated Lecithin is a more stable version of lecithin.

It's made by taking lecithin (a phospholipid commonly found in soybeans and egg yolks) and hydrogenating it. This just means the unsaturated fatty acids are turned into saturated ones so they don't go bad as easily.

This ingredient is an emollient, emulsifier, and penetration enhancer. As an emollient, it helps soften and hydrate skin by trapping moisture within. As an emulsifier, it prevents oil and water ingredients from separating.

Hydrogenated Lecithin can form tiny spherical structures made of phospholipid bilayers called liposomes. These liposomes are able to capture compounds inside their structure and deliver them through the skin barrier.

Because phospholipids are a natural component of our cell membranes, this ingredient is inherently compatible with skin.

A 2021 study found lecithin-based surfactants were less harsh and more tolerable comared to Sodium Lauryl Sulfate (SLS).

Niacinamide is a multitasking form of vitamin B3 that strengthens the skin barrier, reduces pores and dark spots, regulates oil, and improves signs of aging.

And the best part? It's gentle and well-tolerated by most skin types, including sensitive and reactive skin.

You might have heard of "niacin flush", or the reddening of skin that causes itchiness. Niacinamide has not been found to cause this.

In very rare cases, some individuals may not be able to tolerate niacinamide at all or experience an allergic reaction to it.

If you are experiencing flaking, irritation, and dryness with this ingredient, be sure to double check all your products as this ingredient can be found in all categories of skincare.

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.

When you apply niacinamide to your skin, your body converts it into nicotinamide adenine dinucleotide (NAD). NAD is an essential coenzyme that is already found in your cells as "fuel" and powers countless biological processes.

In your skin, NAD helps repair cell damage, produce new healthy cells, support collagen production, strengthen the skin barrier, and fight environmental stressors (like UV and pollution).

Our natural NAD levels start to decline with age, leading to slower skin repair, visible aging, and a weaker skin barrier. By providing your skin niacinamide, you're recharging your skin's NAD levels. This leads to stronger, healthier, and younger looking skin.

Another name for vitamin B3 is nicotinamide. This vitamin is water-soluble and our bodies don't store it. We obtain Vitamin B3 from either food or skincare. Meat, fish, wheat, yeast, and leafy greens contain vitamin B3.

The type of niacinamide used in skincare is synthetically created.

This ingredient is also known as olive oil. It has been used in skincare for centuries and science largely backs up its reputation as a nourishing emollient.

The main components of olive oil are oleic acid (55-83%), linoleic acid (3.5-20%), and palmitic acid (7-20%). Oleic acid promotes skin regeneration and helps regulate inflammatory responses.

Squalene is also naturally present in olive oil and exhibits moisturizing and antioxidant properties.

The polyphenols in olive oil also show anti-aging promise; one clinical study found a measurable improvement in skin appearance after 30 days of topical serum use.

Just be aware that applying olive oil directly to skin can weaken the barrier and cause redness. One study with volunteers found even people without sensitive skin experienced a significant reduction in stratum corneum integrity and induced mild erythema.

It's best to use this ingredient as part of a carefully crafted formula (instead of putting it on skin directly from the bottle).

Because it has a 2-3 on the comedogenic scale, it is a moderate risk for acne-prone skin. However, the overall formulation of a product matters more than a few ingredients with comedogenic ratings.

This ingredient may not be fungal acne safe because of the oleic and palmitic acid content. These fall within the C11-24 fatty acid range that the Malassezia yeast can metabolize to grow.

Overall, olive oil is a well-studied and nourishing skincare ingredient.

Polysorbate 20 is a gentle, water-soluble emulsifier and mild surfactant. It stops oil and water from separating to keep your formulas blended and stable.

It also acts as a mild penetration enhancer by helping active ingredients absorb slightly better.

The common safety discussion around this ingredient involves a manufacturing byproduct called 1,4-dioxane.

Trace amounts can form during production but the EU's Scientific Committee on Consumer Safety has concluded that levels at/below 10 ppm in finished products are safe (commercial products consistently fall within acceptable margins).

True allergic reactions are uncommon and the CIR Expert Panel has confirmed this ingredient to be safe as used in cosmetics.

Because it is derived from lauric acid, it may not be fungal acne safe.

Sodium Polyacrylate is the sodium salt of polyacrylic acid. It is used as an absorber, emollient, and stabilizer.

This ingredient is a super-absorbent polymer - meaning it can absorb 100 to 1000 times its mass in water. As an emollient, Sodium Polyacrylate helps soften and soothe skin. Emollients work by creating a barrier to trap moisture in. This helps keep your skin hydrated.

Stearyl Alcohol is a type of fatty alcohol from stearic acid. It is a white, waxy compound used to emulsify ingredients used as an emollient or to thicken a product.

Emollients help soothe and hydrate the skin by trapping moisture.

Fatty alcohols are usually derived from natural fats and oils and therefore do not have the same drying or irritating effect as solvent (ethanol) alcohols.

The FDA allows products labeled "alcohol-free" to have fatty alcohols.

This ingredient may not be fungal acne safe. It is a primary fatty alcohol with a chain length above 12 carbons. A study from 2019 show Malassezia can feed on fatty alcohols in this range, so it may trigger fungal acne in those prone to it.

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

The reference edit

Ingredients, questions
& further reading.

Connected source records selected through this article’s public topic index.

01

Formula cabinet

Ingredients & structured notes

Ingredient index

Ingredients Explained

  1. 01These ingredients are found in both products.
  2. 02Ingredients higher up in an ingredient list are typically present in a larger amount.
  3. 031,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.
  4. 04It is a:
  5. 05Humectant, drawing moisture into the skin
  6. 06Emollient, helping to soften skin
  7. 07Solvent, dispersing and stabilizing formulas
  8. 08Preservative booster, enhancing the antimicrobial activity of other preservatives
  9. 09Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
  10. 10Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
  11. 11Though 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.
  12. 12Caprylic/Capric Triglyceride (aka MCT Oil) is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping to prevent moisture loss.
  13. 13Though it behaves like an oil, it is not technically one due to its chemical composition. One perk of this ingredient is that it is very stable, resistant to oxidation, and unlikely to go rancid.
  14. 14In practice, that translates to a long shelf life and a consistently elegant skin feel.
  15. 15While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.
  16. 16Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.
  17. 17This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
  18. 18This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures…
  19. 19Cetearyl alcohol is a waxy mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is an emollient and emulsifier.
  20. 20Despite 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.
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side