Overview
What it is
General moisturizer with 11 ingredients
Cool Features
It is reef safe
Suited For
It has ingredients that are good for dry skin and scar healing
Free From
It doesn't contain any harsh alcohols, common allergens, fragrances, parabens, silicones or sulfates
Fun facts
Cerko is from Poland. This product is used in 2 routines created by our community.
We independently verify ingredients and our claims are backed by peer-reviewed research. Does this product need an update? Let us know.
What's inside
Benefits
Concerns
Ingredients Explained
Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.
So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.
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!
Learn more about WaterPetrolatum is more commonly known as petroleum jelly. It is created by mixing waxes and mineral oils.
This ingredient is effective at reducing water loss by 99%. This is because it is an occlusive. Occlusives create a hydrophobic barrier on the skin to prevent evaporation. This property makes it great for hydrating dry skin.
Pro tip: Use occlusives, such as this ingredient, on damp skin for the best results.
The quality or origin of petrolatum is only known when disclosed by the brand. Most cosmetic petrolatum has gone through several purification stages.
Another benefit of occlusives is it protects your skin against infection or allergies.
Petrolatum is fungal acne safe. It is a hydrocarbon with no fatty acid structure, so Malassezia cannot metabolize it. In-vitro studies support negligible growth stimulation as well.
It's also worth noting that petrolatum has a comedogenic rating of 0. In updated rabbit ear testing (and in human testing), petrolatum was found to be not comedogenic. This means it didnât promote comedone formation in standard models.
Learn more about PetrolatumCaprylic/Capric Triglyceride (aka MCT Oil) is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping to prevent moisture loss.
Though it behaves like an oil, it is not technically one due to its chemical composition. One perk of this ingredient is that it is very stable, resistant to oxidation, and unlikely to go rancid.
In practice, that translates to a long shelf life and a consistently elegant skin feel.
While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.
Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredientâs final chemical composition and not its marketing name or source.
This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures at concentrations as low as 0.2%.
Learn more about Caprylic/Capric TriglycerideGlycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
Topically, glycerin does several things at once:
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.
Learn more about GlycerinPolyglyceryl-4 Isostearate is a plant-derived, PEG-free emulsifier.
It's made by hooking isostearic acid onto a chain of glycerin units to give it a water-loving "head" and oil-loving "tail". This allows it to keep the oil and water mixed in a formula.
The highest reported concentration is about 24% in eye makeup but most suppliers recommend a level below 10%.
It has a clean track record for safety and found to be non-irritating.
Because it is an ester of a C18 fatty acid, Malassezia can potentially metabolize it (it sits in the C11-24 range that Malassezia likes). Therefore, this ingredient may not be fungal acne safe.
Learn more about Polyglyceryl-4 IsostearateThis ingredient is also known as shea butter. It is a plant-derived extract from the nuts of the Africa shea tree and one of the most well-studied emollients.
Because it has a high concentration of fatty acids (primarily oleic, stearic, and linoleic) it is able to form a protective barrier on the skin's surface. This helps seal in moisture and prevents transepidermal water loss (TEWL).
In vitro research found an increase in skin hydration by 58% and a decrease in TEWL by 37.8% after 24 hours of applying this ingredient (pretty impressive for a single ingredient!).
Besides hydration, shea butter also contains triterpenes that have anti-inflammatory potential. In particule, lupeol cinnamate has shown the highest anti-inflammatory activity in vivo.
Shea butter also contains vitamins A and E which may contribute to antioxidant activity.
While Shea Butter has an SPF rating of about 3-4, it is not a sunscreen replacement.
This ingredient may not be fungal acne safe because its fatty acids fall within the C11-C24 range that the Malassezia yeast can metabolize.
Learn more about Butyrospermum Parkii ButterPentylene glycol is typically used within a product to thicken it. It also adds a smooth, soft, and moisturizing feel to the product. It is naturally found in plants such as sugar beets.
The hydrophilic trait of Pentylene Glycol makes it a humectant. As a humectant, Pentylene Glycol helps draw moisture from the air to your skin. This can help keep your skin hydrated.
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.
Learn more about Pentylene GlycolOctyldodecanol is a fatty alcohol sourced from plant oils like coconut or palm (or made synthetically).
It is:
You'll likely see this in many BHA products because this is the go-to solvent for salicylic acid.
This ingredient is typically used at levels between 2-20%.
Regarding fungal acne:
In 2019, this ingredient was tested against multiple Malassezia species (the yeast that causes fungal acne) and showed no growth.
Paraffinum Liquidum is a highly-refined cosmetic-grade mineral oil. It is also known as liquid paraffin.
Despite its controversial reputation, the science is pretty clear: it's one of the most well-studied and effective moisturizing ingredients out there.
As an occlusive, it forms a protective layer on the skin that locks in moisture and prevents transepidermal water loss (TEWL). This makes it especially great for compromised skin barriers.
The "it clogs your pores" myth has been around for decades; a study found that industrial-grade mineral oil may be comedogenic but cosmetic-grade mineral oil is not (these two are very, very different).
A 2017 review concluded that cosmetic use of mineral oils and waxes does not present a risk to consumers due to absorption.
Mineral oil got a bad rap from the old rabbit ear studies. When tested on actual human skin, cosmetic-grade mineral oil showed no comedogenic activity. The rating of 0 is a correction of outdated science.
Mineral oil is an inert substance with no fatty acids so there's nothing to feed Malassezia. This ingredient is fungal acne safe.
Learn more about Paraffinum LiquidumMagnesium Sulfate is a salt. More specifically, it is an epsom salt, or the bath salt used to help relieve muscle aches.
Despite having âsulfateâ in the name, it isnât a surfactant or cleansing agent like sodium lauryl sulfate. Unlike those sulfates, magnesium sulfate doesnât have the same cleansing or foaming properties (it's simply a type of salt).
In cosmetics, Magnesium Sulfate is used to thicken a product or help dilute other solids. It is a non-reactive and non-irritating ingredient.
One study shows magnesium deficiency may lead to inflammation of the skin. Applying magnesium topically may help reduce inflammation.
You can find this ingredient in sea water or mineral deposits.
Learn more about Magnesium SulfateLactic Acid is another well-loved alpha hydroxy acid (AHA). It is gentler than glycolic acid but still highly effective.
Its main role is to exfoliate the surface of the skin by loosening the âglueâ that holds dead skin cells together. Shedding those old cells leads to smoother, softer, and more even-toned skin.
Because lactic acid molecules are larger than glycolic acid, they donât penetrate as deeply. This means theyâre less likely to sting or irritate, making it a great choice for beginners or those with sensitive skin.
Like glycolic acid, it can:
Lactic acid also acts as a humectant (like hyaluronic acid). It can draw water into the skin to improve hydration and also plays a role in the skin's natural moisturizing factor (NMF) in the form of sodium lactate.
Studies show it can boost ceramide production to strengthen the skin barrier and even help balance the skinâs microbiome.
To get results, choose products with a pH between 3-4.
Lower strengths (5-12%) focus on surface exfoliation; higher strengths (12% and up) can reach deeper in the dermis (deeper, supportive layer) to improve skin texture and firmness over time.
Though it was originally derived from milk, most modern lactic acid used in skincare is vegan. It is made through non-dairy fermentation to create a bio-identical and stable form suitable for all formulations.
When lactic acid shows up near the end of an ingredient list, it usually means the brand added just a tiny amount to adjust the productâs pH.
Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.
Lactic acid is truly a gentle multitasker: it exfoliates, hydrates, strengthens, and brightens. It's a great ingredient for giving your skin a smooth, glowing, and healthy look without the harshness of stronger acids.
Read more about some other popular AHA's here:
Learn more about Lactic AcidReviews
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Where it's from
Cerko is a Polish brand
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The data we've presented on this page has been verified by a member of the SkinSort Team.
Read more about us¡ Updated April 10, 2026 • Added by leonkamiski