Cosmocost Gentle Vitamin C Custom Serum
A serum with 10 ingredients, including vitamin C and vitamin E.
Overview
What it is
Serum with 10 ingredients that contains Vitamin C and Vitamin E
Cool Features
It is reef safe
Suited For
It has ingredients that are good for anti aging, dry skin, brightening skin, sensitive skin, reducing pores, scar healing, dark spots and better texture
Free From
It doesn't contain any harsh alcohols, common allergens, fragrances, parabens, silicones or sulfates
Fun facts
Cosmocost is from United States.
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
Key Ingredients
Benefits
Ingredients Explained
Squalane is the hydrogenated and shelf-stable form of squalene (a lipid that naturally occurs in human sebum).
It is an emollient and skin conditioning agent that is able to integrate seamlessly into the skin's lipid barrier without clogging pores.
This is due to how structurally similar it is to what your skin already produces.
Though it is mostly an emollient that helps soften and hydrate skin, it also has some humectant and occlusive action. Humectants help the skin retain moisture while occlusives seal it in, making squalane a triple-threat moisturizer.
Research shows it has antioxidant capabilities that help protect against stressors like UV exposure, specifically UVA induced oxidative stress. This study also found that it supports collagen biosynthesis in human dermal fibroblasts.
No clinical study has reported significant adverse effects and irritation reactions are very rare from this ingredient (even at 100% concentration).
Overall, it's a fantastic ingredient for hydration and is suitable for all skin types.
This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.
Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.
Read more about squalene with an "e".
Though squalane is often called an oil, itâs technically not one. It is a hydrocarbon, meaning it is only made of carbon and hydrogen. True oils are triglycerides and made of fatty acids and glycerol.
The term âoil-freeâ isnât regulated so companies can define it however they want. Some exclude all oils, while others just avoid mineral oil or comedogenic oils.
Squalane has a comedogenic rating of 1 from the original 1972 study that tested raw ingredients under occlusion on rabbit ears. This system is not standardized or peer-reviewed, and using the raw ingredients is very different from how diluted cosmetic formulations are used on human skin.
A comedogenic rating of 1 means it is "unlikely to clog pores" according to the original rating system.
The overall formula of a product matters more than the individual ingredients on whether or not it will cause clogged pores.
Learn more about SqualaneTetrahexyldecyl Ascorbate (THD) is a stable and oil-soluble form of Vitamin C.
THD is special in that it has the ability to travel deeper into skin than traditional ascorbic acid while maintaining the same skin benefits (double win!).
Because itâs oil-soluble, THD dives deep into your skinâs fatty layers (think ceramides and cholesterol) to fight off the kind of free radicals that mess with your skin barrier. This makes it a great pair with water-based vitamin C (ascorbic acid) that mainly works on the surface.
Even at just 0.1%, THD is already showing great antioxidant activity. When used up to 2%, it helps keep your skin happy and calm, especially when itâs stressed from pollution or sun.
Want to fade dark spots or tackle hyperpigmentation? Youâll want 5% or more. Pairing it with brightening buddies like niacinamide or licorice root gives even better results. One study even used 30% THD with other brighteners and saw real results on stubborn discoloration, even in melasma-prone skin.
A note on THD: Itâs has a slightly silky, oily texture and usually shows up colorless or pale yellow (though the exact shade can vary by supplier).
While you can sneak it into water-based formulas, it really shines when paired with silicones or oils, which help your skin soak it up better.
THD is pretty stable, but itâs still vulnerable to degradation like ascorbic acid. Too much light or heat (above 113°F / 45°C) can break it down over time. Go for dark and opaque packaging that keeps it safe and shady!
Read more about other types of Vitamin C:
Learn more about Tetrahexyldecyl AscorbateDimethyl Isosorbide is a low-irritation solvent that helps deliver actives into your skin. It is created from glucose.
Research shows how well this ingredient works depends on the active and formulation rather than the concentration alone. This means adding more Dimethyl Isosorbide does not guarantee better penetration of ingredients into the skin.
C12-15 Alkyl Benzoate is made up of Benzoic Acid and long chain alcohols. It has a low molecular weight.
C12-15 Alkyl Benzoate is an emollient and texture enhancer. Due to its solubility, it is often used in sunscreens to help evenly distribute active ingredients.
As an emollient, C12-15 Alkyl Benzoate helps soften and hydrate your skin. Emollients create a film on your skin that traps moisture within.
This ingredient has been reported to cause eye irritation.
Learn more about C12-15 Alkyl BenzoateThis ingredient is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping the skin prevent moisture loss.
It helps thicken a product's formula and makes it easier to spread by dissolving clumping compounds.
Caprylic Triglyceride is made by combining glycerin with coconut oil, forming a clear liquid. Though it behaves like an oil, it is not technically one due to its chemical composition. 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. Be sure to 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.
Learn more about Caprylic/Capric TriglycerideSambucus Nigra is known as the black elderberry.
Black Elderberry contains flavonoids, which are antioxidants. Antioxidants help fight free-radicals. Free-radicals are molecules that may damage your skin cells.
Glycyrrhiza Glabra Root Extract is an extract of the roots of Licorice. It has been found to have several benefits such as skin hydrating, conditioning, and soothing.
One component, glabridin, has extra potent antioxidant and soothing properties. It has also been found to block pigmentation from UVB rays in guinea pigs.
Licorice Root also contains a flavonoid. Flavonoids are a natural substance from in plants. Flavonoids also have antioxidant properties.
Another component, glycyrrhizin, has been found to have anti-inflammatory and antimicrobial benefits. This may make licorice root extract effective at treating acne. However, more research is needed to support this.
Liquiritin is one of the flavone compounds found in licorice. It has been found to help lighten skin by preventing tyrosinase from reacting with tyrosine. When the two react, protein is converted to melanin. Melanin is the substance in your body that gives your features pigmentation.
Learn more about Glycyrrhiza Glabra Root ExtractThis ingredient is the oil from the apricot.
Apricot Kernel Oil is an emollient and helps soften skin. This is due to its fatty acid components. Some of these fatty acids include linoleic and oleic acid.
This ingredient also has antioxidant properties from Vitamins A, C, and E. Antioxidants help fight free-radicals. Free-radicals are molecules that may damage your skin cells. Besides being antioxidants, these vitamins provide plenty of skin benefits as well.
Learn more about Prunus Armeniaca Kernel OilTocopherol is a fat-soluble antioxidant known as Vitamin E.
You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.
Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.
It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.
This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.
This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.
In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.
Concentrations usually range from 0.1-1% in most leave-on products.
Learn more about TocopherolAcetyl Zingerone is an antioxidant from ginger. It is able to fight many types of free-radical damage.
Acetyl Zingerone is stable in sun and is able to disrupt UV damaging processes on the skin.
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Where it's from
Cosmocost is a American brand
We're dedicated to providing you with the most up-to-date and science-backed ingredient info out there.
The data we've presented on this page has been verified by a member of the SkinSort Team.
Read more about us· Updated June 4, 2026 • Added by TiredSkincareEnthusiast