TONYMOLY Strawberry Hand Cream Versus Pleasing Hand + Nail Balm

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.

Industry survey data shows this ingredient is used around 1-5% but Glyceryl Stearate goes as high at 17% in a leave-on deodorant.

Safety-wise, it's pretty boring: it's been deemed safe for topical use in 1982 and again most recently in 2021 by the CIR. Human repeat insult patch tests come back non-irritating, non-sensitizing, non-phototoxic, and non-photoallergenic.

This ingredient does carry a comedogenic rating of 3 from the old rabbit-ear assay. Just remember testing finished products in humans showed that formulas built with "comedogenic" ingredients are not necessarily comedogenic themselves. It's worth patch testing if you're breakout prone, and always listen to your skin.

The Malassezia yeast can potentially metabolize the stearic acid in this ingredient, so it may not be fungal acne safe.

Allergy is rare: a 310-patient patch test study of common emulsifiers found this ingredient was not a meaningful reactor. Isolated case reports do exist so a true contact allergy is possible but uncommon.

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.

Vitamin E is also prevalent in this ingredient and the most dominant form is gamma-tocopherol.

These compounds give the ingredient emollient and skin conditioning properties that keep the skin soft and hydrated.

There's no regulatory maximum cap for this ingredient so you'll see it across a huge concentration range (100% as a single ingredient facial oil).

On allergies: refined cosmetic-grade oils carry almost no protein. The CIR notes that people allergic to a food generally do not react to the refined oil because the allergenic protein does not partition into it (though cold-pressed grades retain more).

However, it's worth patch testing if you have a stone fruit or tree nut allergy because manufacturer processes for removing the protein can vary.

Malassezia lacks the cytosolic fatty acid synthase gene so the yeast cannot make palmitate on its own and instead uses lipases and phospholipases to release fatty acids from host lipids. Since apricot kernel oil is entirely C16-18 (right in the usable range of C11-24), this ingredient may not be fungal acne safe.

Old rabbit-ear testing did assign this ingredient a comedogenic rating of 1-2. The original author has stated that testing on rabbit ears is not an ideal model for human comedogenicity.

Human testing has proved that any finished product with a comedogenic ingredient won't automatically make you break out; it really comes down to concentration, formula, and your skin.

Just know high-oleic oils tend to feel heavier on oily skin so it's worth patch testing.

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!