Creamy Pro-Adapaleno Serum

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.

Tocopheryl Acetate is commonly found in both skincare and dietary supplements.

The CIR Expert Panel assessed the safety of 126 acrylates copolymers and concluded they are safe in cosmetics at current use levels when formulated to be non-irritating. They also noted the levels present in finished cosmetic products are not considered a safety risk and Genotoxicity testing (Ames tests, chromosomal aberration assays) has come back negative across the board.

Though the raw building blocks (like acrylic acid) can be irritating on their own, cosmetic-grade versions go through purification to keep levels extremely low.

Sodium Acrylates Copolymer is a large molecule that doesn't penetrate skin barrier in any meaningful way.

Another perk? It doesn't share the oxidative instability issues that vitamin A derivatives like retinol or retinaldehyde have.

One 12-week, double-blind, randomized trial found 0.5% OA was better at reducing wrinkle severity, comparable in improving pigment intensity, and was tolerated better than 0.5% retinol.

At 12 weeks, only 5% of the OA group reported burning and 10% reported scaling. The retinol group reported much higher rates of itching, burning, stinging, scaling, and redness.

Just remember this is a relatively new ingredient with limited long-term data; researchers noted the 12 week study's single trial site and short duration as limitations and recommended further studies with more diverse populations and longer timelines.

This ingredient is typically used at levels between 0.1% - 0.5%.

It plays well with most ingredients and is typically used at 0.1-1%. However, concentrations up to 50% have been reported in moisturizers.

Depending on the source of this ingredient, lecithin may not be fungal acne safe. This is because some sources of lecithin come from soybean oil, which may feed the malassezia yeast that causes fungal acne.

We recommend reaching out to the brand you are purchasing from to inquire about the source of their lecithin.

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.

Chelating agents help neutralize unwanted metals from affecting the formulation.

Sodium gluconate is water-soluble.

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

As a preservative, it is used to stabilize products and prevent them from degrading. Specifically, BHT prevents degradation from oxidation.

The concerns related to BHT come from oral studies; this ingredient is currently allowed for use by both the FDA and EU.

However, it was recently restricted for use in the UK as of April 2024.