COSRX Full Fit Propolis Honey Overnight Mask Versus COSRX Ultimate Moisturizing Honey Overnight Mask

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.

In comedogenic testing, Beeswax scored a 0-2, which is on the low end. Whether or not a product clogs your pores really comes down to the formula as a whole (not any single ingredient on its own).

Cera Alba is the white, bleached form of this ingredient.

Just so you know, beeswax is not vegan since it is animal-derived. It cannot be removed with water, but can be taken off with an oil cleanser.

People with a known Propolis allergy also report to have reactions from beeswax.

Some studies suggest betaine may support making skin tone more even.

Fun fact: Betaine naturally exists in the skin and the body. In cosmetic products, it can be either plant-derived (most commonly from sugar beets) or synthetically produced for consistency and stability.

Betaine is also known as trimethylglycine.

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.

A high amount of carbomer can cause pilling or balling up of products. Don't worry, most products contain 1% or less of carbomer.

Research on the seeds have shown that some of the compounds in the extract demonstrate antioxidant activity comparable to Ascorbic Acid.

Please know that Ascorbic acid does have decades of research so it is still the gold standard. But there's no harm in using this as a supportive ingredient unless you have a legume allergy. Those with a legume allergy should definitely patch test.

Fun fact: This ingredient has been used in traditional Chinese and Korean medicine for centuries.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

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.

D-panthenol is also known as dexpanthenol. Most cosmetics use dexpanthenol or a mixture of D and L-panthenol.

Panthenol is famous due to its ability to go deeper into the skin's layers. Using this ingredient has numerous pros (and no cons):

Like hyaluronic acid, panthenol is a humectant. Humectants are able to bind and hold large amounts of water to keep skin hydrated.

This ingredient works well for wound healing. It works by increasing tissue in the wound and helps close open wounds.

Once oxidized, panthenol converts to pantothenic acid. Panthothenic acid is found in all living cells.

This ingredient is also referred to as pro-vitamin B5.

Research shows it can help:

It also pairs nicely with hydrating ingredients like niacinamide and ceramides.

Just so you know, Propolis Extract is recognized as a contact allergen. In patch tests done in the EU, roughly 1-6% of patients react to it. Be sure to steer clear of this ingredient if you have a known allergy to bee products.

Since it is an animal-derived product, this ingredient is not considered vegan. For vegan alternatives, check out Galactomyces Ferment Filtrate or Centella Asiatica Extract.

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.