Meder Net-Apax Prebiotic Cleansing Mask

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.

You'll see this one rated 4 comedogenic all over the internet. That number isn't from a single study, and the actual research is more interesting.

The original rating comes from 1980s rabbit ear tests (which are a shaky basis for anything). But Ethylhexyl Palmitate is one of the few ingredients with real human data behind it. A 2021 controlled trial found this ingredient increased microcomedones by an average of 365% over four weeks.

Just know that test used the pure ingredient under an occlusive pad on back skin; most products use it at much lower levels alongside other ingredients and plenty of people use those with no issue.

Older ingredient lists label it as "Octyl Stearate" and it turns up the most often in makeup products.

Industry data shows usage concentration goes up to ~40% in makeup and up to 10% in moisturizer or sunscreen.

Human repeat insult patch tests with a 25.9% lip gloss and 38.8% eyebrow pencil found no sensitization. A formula with 7.6% was also not an irritant, sensitizer, and was found to be non-phototoxic across 56, 19, and 27 subjects respectively.

True contact allergy to it is rare.

This ingredient shows up on a lot of "pore-clogging" lists but there's no real evidence behind that. It doesn't even have a comedogenic rating from an actual study; the numbers you'll find online come from blogs citing other blogs.

Ratings for other ingredients mostly come from a 1980s rabbit ear test. This test doesn't translate well to human skin or to real products because the ingredient sits at a much lower percentage.

Some people still find it breaks them out. So if that's you, definitely trust your skin.

The Malassezia yeast has been found to grow in the presence of fatty acids, fatty acid esters, and fatty alcohols with chains longer than 12 carbons. Ethylhexyl Stearate releases stearic acid, an 18-carbon chain, which is right inside that range; this ingredient may not be fungal acne safe.

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

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.

On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.

Another perk of this ingredient is that it stays functional across a wide pH range (3-10).

You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.

Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.

Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.

Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.

Isohexadecane is often used in products designed to help oily skin. It is lightweight and non-greasy while helping to moisturize. When mixed with silicones, it gives a product a silky feel.

The CIR Expert Panel has evaluated the scientific data and found this ingredient to be safe, non-irritating, and non-sensitizing at concentrations up to 5% (it's even approved by the FDA as an OTC eye drop ingredient).

It can also form a thin protective film on skin. One study found that a formula using this polymer helped slow down how quickly other ingredients (like DEET) were absorbed through skin.

A 2024 study of over 1,300 patients confirmed that sensitization to this ingredient is rare. It is also non-mutagenic and has a clean track record.

Typical use levels in formulas range from 2-10%.

The CIR Expert Panel has concluded this ingredient to be safe as a cosmetic ingredient.

Since this ingredient is an ester of oleic acid, it may not be fungal acne safe. Oleic acid is a fatty acid that falls into the C11-24 range that Malassezia can metabolize.

This ingredient does have a comedogenic rating of 3, but this doesn't mean a formula with this ingredient will clog pores. 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.

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.