Beauty of Joseon Dynasty Cream (Old Formulation) Versus Numbuzin No.3 Velvet Beauty Cream

In vitro research found an increase in skin hydration by 58% and a decrease in TEWL by 37.8% after 24 hours of applying this ingredient (pretty impressive for a single ingredient!).

Besides hydration, shea butter also contains triterpenes that have anti-inflammatory potential. In particule, lupeol cinnamate has shown the highest anti-inflammatory activity in vivo.

Shea butter also contains vitamins A and E which may contribute to antioxidant activity.

While Shea Butter has an SPF rating of about 3-4, it is not a sunscreen replacement.

This ingredient may not be fungal acne safe because its fatty acids fall within the C11-C24 range that the Malassezia yeast can metabolize.

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.

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.

As an emollient, it can help the skin feel soft and hydrated. It is also used to reduce frizz in hair products.

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.

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).

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.

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.

Typical use concentrations range from 2-3% and it works across a pH of 4.5-8.5.

This ingredient has been found safe to use in cosmetics and has a low irritation profile.

Because it's build on stearic acid, it may not be fungal acne safe. Stearic acid is a C18 fatty acid that falls within the range (C11-24) that Malassezia can feed on.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

Due to its antioxidant properties, trehalose may help with signs of aging. Antioxidants help fight free-radical molecules, unstable molecules that may damage your skin.

In medicine, trehalose and hyaluronic acid are used to help treat dry eyes.

Some animals, plants, and bacteria create trehalose as a source of energy to survive freeze or lack of water.

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!