Bioderma ABCDerm Péri-Oral Soothing Cream

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.

One thing worth noting: a controlled study found this ingredient applied under occlusion to acne-prone subjects increased microcomedones. Just keep in mind this was under occlusive conditions and don't reflect how most products are used day-to-day.

For most people, this is a well-tolerated and lightweight ingredient.

This ingredient may not be fungal acne safe because it is an ester of palmitic acid, a C16 fatty acid that falls within the C11-24 range that Malassezia can metabolize.

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.

Emerging studies show Capryloyl Glycine may inhibit hair growth. It may also cause allergies for some people. We recommend speaking with a professional if you have any questions about this ingredient.

Fun fact: This ingredient is also used to mask the bitter taste of medicine.

On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.

Typical use levels in a formula run about 1-5%.

The unique structure of silica enhances the spreadability and adds smoothness, making it a great texture enhancer.

It is also used as an active carrier, emulsifier, and mattifier due to its ability to absorb excess oil.

In some products, tiny microneedles called spicules are made from silica or hydrolyzed sponge. When you rub them in, they lightly polish away dead skin layers and enhance the penetration of active ingredients.

The manufacturer also claims this ingredient to be useful in makeup.

In lipstick formulations, this ingredient improves color payoff, reduces pigment settling, and reduces oil bleeding. This ingredient also improves the grip of powder products such as dry shampoos.

According to EU CosIng, this ingredient helps soften skin, keep oil and water stay mixed, and thickens products.

Hydrogenated castor oil at 30% did not trigger a positive patch-test reaction and is well-tolerated.

Since this ingredient is based on an 18-carbon fatty acid, it falls into the chain-length range that Malassezia can feed on and may not be fungal acne safe.

Research shows it can encourage your skin cells to turn over and renew by stimulating keratinocyte and fibroblast proliferation.

It also has mild keratolytic properties to help loosen and shed dead skin cells without being harsh.

Studies also suggest allantoin can help calm inflammation by dialing down some of the chemical signals your skin sends out when it is irritated.

This ingredient is typically used in the 0.1-0.5% range, and the FDA recognizes it as a skin protectant in OTC products up to 2%.

Overall, allantoin is a wonderful addition to most routines; it is stable across a wide pH range (~4-8), works well with other ingredients, and is considered non-sensitizing/non-irritating.

Fun fact: Allantoin is naturally occurring in comfrey root, beets, chamomile, and wheat sprouts. Our bodies even produce it as a byproduct of uric acid metabolism.

The acidity of our skin is maintained by our glands and skin biome; normal pH level of skin is slightly acidic (~4.75-5.5).

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.

Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.

"Alkaline" refers to a high pH level. A low pH level would be considered acidic.

In cosmetics, it mainly functions as a bulking agent, viscosity controller, binder, and absorbent. It helps thicken products, stabilize powders, and get certain textures a less "wet" feel.

This ingredient has a pretty solid safety profile; it's recognized as a safe food additive and its large molecular size means it doesn't meaningfully penetrate skin.

Human repeat insult patch tests using a rinse-off facial product containing 42.69% dextrin found no skin irritation or sensitization in 54 subjects.

Typical real-world usage is much lower: usually under 1% as a texture modifier and up to 40% in masks (rinse off products use less).