Elyn's Lab Cosmetics Sunsqueen SPF 50 Sunscreen Versus Beauty of Joseon Relief Sun Aqua-Fresh Rice + B5 SPF 50+

On the surface, it acts as a humectant that holds water in place and reduces moisture loss for a plumper, smoother feel, while its anti-inflammatory and antioxidant properties make it a great pick for calming redness or sensitive skin

The more interesting story is underneath:

Despite its large molecular size, oat beta-glucan has been shown to penetrate the epidermis and reach the dermis by slipping between skin cells. Here, it interacts with fibroblasts and macrophages to nudge collagen synthesis and support wound repair.

A small 2005 split-face clinical study of 27 subjects found topical beta-glucan produced measurable reductions in wrinkle depth, height, and roughness after 8 weeks of use.

It is worth noting the trial was small and the penetration testing used frozen, irradiated skin so the anti-aging data is encouraging rather than definitive.

This ingredient gets along with pretty much everything and is typically used around 0.1-1%.

Fungal acne: This ingredient is not a food source for the Malassezia yeast because it is a glucose polysaccharide with no fatty acid or ester component.

Photostabilizers help stabilize UV-filters and prevents them from degrading quickly.

Unlike the extract, this ingredient only carries trace amounts of catechins, amino acids, and caffeine that makes tea leaf extract famous.

This ingredient is volatile which means it will mostly evaporate (but it evaporates slower than older cyclomethicones, like Cyclotetrasiloxane).

Typical concentration ranges from 1-30% depending on if it's being used to tweak the feel of a product or acting as the main emollient.

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

Participants reported visible improvement and good tolerance.

This ingredient has been found to be safe as used in cosmetics, wasn't a skin or eye irritant in clinical patch testing, and wasn't phototoxic.

In a clinical comedogenicity test, this ingredient tested negative so it isn't likely to clog pores.

Typical use levels are about 5-8% for sunscreens + nail products, but can range from 0.005%-8% depending on the product.

DHHB has been approved by the EU, Japan, Taiwan, and South America for use up to 10%. Unfortunately, it has not been approved for use in the US or Canada due to slow regulatory processes.

This ingredient is soluble in oils, fats, and lipids.

The standout trait is photostability. Unlike other UV filters, this one doesn't break down when exposed to sunlight.

You'll likely see it paired with Mexoryl SX (Ecamsule) because the two filters show a synergistic effect where the combined protection is greater than the sum of the individual filters.

Because it is oil soluble, it's great for water-resistant/sport/beach sunscreens.

Concentration-wise, the EU permits up to 15% but formulas use it well below that ceiling and almost never as a solo active.

It has a pretty solid safety record: allergic reactions are considered rare, its large molecule size means little to no absorption through skin, and toxicology reviews found no significant toxicity.

Just so you know, there were a handful of isolated allergic contact dermatitis case reports (which is true of every UV filter), but most people will not react to it.

This ingredient is available in the EU, Canada, Australia, and Japan, but not the US. This is just because the manufacturer hasn't pushed the data through the FDA's OTC ingredient pathway.

Formulators love it for its stability; its ability to filter UV stays practically unchanged even under intense radiation and it can also help boost the photostability of less stable filters like avobenzone.

It's also a great pick for water resistant products because it's insoluble in water and has a good affinity for keratin.

Because it's a big, heavy molecule, the European Scientific Committee has found to to have very low dermal penetration and negative results for allergenicity.

In vitro testing also showed a low absorption rate and clean results on irritation.

Typical use levels are 1-5% with 5% being the maximum in the EU, Japan, and other markets that allow it. However, this ingredient is not approved yet in the US or Canada.

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.

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).

Methylpropanediol is able to add a bit of moisture to the skin. It also helps other ingredients be better absorbed into the skin, such as salicylic acid.

This property also makes Pentylene Glycol a great texture enhancer. It can also help thicken or stabilize a product.

Pentylene Glycol also acts as a mild preservative and helps to keep a product microbe-free.

Some people may experience mild eye and skin irritation from Pentylene Glycol. We always recommend speaking with a professional about using this ingredient in your routine.

Pentylene Glycol has a low molecular weight and is part of the 1,2-glycol family.

Polymethylsilsesquioxane has not been shown to clog pores. It has been deemed safe to use up to 55%, but most cosmetics use much less.

If you have concerns about using this ingredient, we recommend speaking with a professional.

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

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.

Tromethamine helps balance the pH level of a product. Normal pH level of skin is slightly acidic (~4.75-5.5). The acidity of our skin is maintained by our glands and skin biome. Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.

Oral Tromethanmine is an anti-inflammatory drug but plays the role of masking, adding fragrance, and/or balancing pH in skincare.

1,3-Propanediol, 2-amino-2-(hydroxymethyl)-

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!

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.