Yon-ka Serum Omega
A serum with 33 ingredients, including vitamin E.
This hydrating serum is formulated around Glycine Soja Oil to hydrate skin.
Worth noting
Contains EU-listed fragrance allergens, including Lavandula Angustifolia Extract and Lavandula Oil/Extract.
We independently verify ingredients, backed by peer-reviewed research. Suggest an update.
What's inside
Ingredients List
Glycine Soja Oil
EmollientZea Mays Germ Oil
EmollientHelianthus Annuus Seed Oil
EmollientParfum
MaskingEthyl Linoleate
EmollientEthyl Linolenate
EmollientRosmarinus Officinalis Leaf Oil
MaskingEthyl Oleate
EmollientCupressus Sempervirens Oil
MaskingTocopheryl Acetate
AntioxidantEthyl Palmitate
EmollientLavandula Angustifolia Extract
Skin ConditioningThymus Vulgaris Flower/Leaf Oil
MaskingEthyl Stearate
EmollientPelargonium Graveolens Leaf Oil
Tocopherol
AntioxidantLavandula Oil/Extract
Eucalyptus Globulus Oil
Geraniol
PerfumingGeranyl Acetate
PerfumingLimonene
PerfumingCoumarin
PerfumingLinalool
PerfumingCitronellol
PerfumingCitral
PerfumingMenthol
MaskingPinene
MaskingLinalyl Acetate
MaskingCamphor
MaskingBeta-Caryophyllene
MaskingTerpinolene
PerfumingAlpha-Terpinene
PerfumingTerpineol
MaskingGlycine Soja Oil, Zea Mays Germ Oil, Helianthus Annuus Seed Oil, Parfum, Ethyl Linoleate, Ethyl Linolenate, Rosmarinus Officinalis Leaf Oil, Ethyl Oleate, Cupressus Sempervirens Oil, Tocopheryl Acetate, Ethyl Palmitate, Lavandula Angustifolia Extract, Thymus Vulgaris Flower/Leaf Oil, Ethyl Stearate, Pelargonium Graveolens Leaf Oil, Tocopherol, Lavandula Oil/Extract, Eucalyptus Globulus Oil, Geraniol, Geranyl Acetate, Limonene, Coumarin, Linalool, Citronellol, Citral, Menthol, Pinene, Linalyl Acetate, Camphor, Beta-Caryophyllene, Terpinolene, Alpha-Terpinene, Terpineol
Key Ingredients
Benefits
Concerns
Ingredients Explained
Glycine Soja Oil is a plant-derived oil from soybean seeds. Like other oils, it is rich in essential fatty acids (mostly linoleic and oleic) that support skin hydration and barrier function.
The fatty acids are able to integrate into the lipid matrix of the stratum corneum to help soften skin and reduce water loss.
On top of that, soybean oil is rich in vitamins like vitamin E, a potent antioxidant.
Research on soybean's active components also point to anti-inflammatory, collagen-stimulating, antioxidant activity, and protection against UV-induced oxidative damage.
Most of this research applies to the broader soybean plant and not just the oil fraction alone.
This ingredient may not be fungal acne safe due to the oleic acid content.
Learn more about Glycine Soja OilZea Mays Germ Oil comes from corn.
It is an occlusive skin conditioning agent.
Helianthus Annuus Seed Oil is a plant oil derived from the seeds of a sunflower.
It is rich in fatty acids, primarily linoleic acid and oleic acid. This gives it emollient and skin conditioning properties.
The reason this ingredient is so effective is because it forms a thin film on the skin that reduces transepidermal water loss (TEWL) while supplying linoleic acid to the stratum corneum to improve barrier strength.
The high linoleic acid content is particularly noteworthy for acne-prone skin.
Research suggests that acne-prone skin tends to be deficient in linoleic acid in sebum. Topical application may help replenish this to support a healthier follicular environment and less comedone-promoting sebum.
One randomized study found sunflower seed oil preserved skin barrier integrity in adult volunteers with and without atopic dermatitis (outperforming olive oil).
This ingredient is well-studied, gentle, and an effective emollient suitable for most skin types.
On fungal acne: This ingredient may not be Fungal acne (Malassezia folliculitis) safe. This is because it contains fatty acids with carbon chain lengths in the C11-C24 range.
Learn more about Helianthus Annuus Seed OilParfum is a catch-all term for an ingredient or more that is used to give a scent to products.
Also called "fragrance", this ingredient can be a blend of hundreds of chemicals or plant oils. This means every product with "fragrance" or "parfum" in the ingredients list is a different mixture.
For instance, Habanolide is a proprietary trade name for a specific aroma chemical. When used as a fragrance ingredient in cosmetics, most aroma chemicals fall under the broad labeling category of “FRAGRANCE” or “PARFUM” according to EU and US regulations.
The term 'parfum' or 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term.
For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance by INCI standards.
One example is Calendula flower extract. Calendula is an essential oil that still imparts a scent or 'fragrance'.
Depending on the blend, the ingredients in the mixture can cause allergies and sensitivities on the skin. Some ingredients that are known EU allergens include linalool and citronellol.
Parfum can also be used to mask or cover an unpleasant scent.
The bottom line is: not all fragrances/parfum/ingredients are created equally. If you are worried about fragrances, we recommend taking a closer look at an ingredient. And of course, we always recommend speaking with a professional.
Learn more about ParfumEthyl Linoleate is a fragrance and isn't fungal acne safe.
Ethyl Linolenate isn't fungal acne safe.
Rosmarinus Officinalis Leaf Oil is an essential oil also known as rosemary essential oil. In skincare, it is a skin conditioning agent and also acts as a natural fragrance that gives products a fresh/herby smell.
The oil is a mix of over 100 volatile compounds with 1,8-cineole, α-pinene, camphor, and verbenone usually leading the pack.
Lab studies credit this oil with antioxidant, anti-inflammatory, and antimicrobial activity. Some research even show rosemary compounds calming acne-related inflammation.
The Cosmetic Ingredient Review (CIR) has concluded rosemary-derived ingredients to be safe when formulated to be nonsensitizing.
Since this is a fragrant essential oil, the main concern is for fragrance-sensitive folks.
Learn more about Rosmarinus Officinalis Leaf OilEthyl Oleate is a fragrance and isn't fungal acne safe.
Cupressus Sempervirens Oil is an oil.
Tocopheryl Acetate is a stable, shelf-friendly form of vitamin E.
Formulators love it because plain vitamin E oxidizes quickly once it hits air. This acetate version stays stable and resists going off, helping to extend a product's shelf life.
It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.
One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.
Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.
Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.
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.
Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.
The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.
Most leave-on skincare keeps it at the lower end, often between 0.5-1%.
Learn more about Tocopheryl AcetateEthyl Palmitate is a fragrance and isn't fungal acne safe.
Lavandula Angustifolia Extract comes from the flowers and leaves of the lavender plant. It's mostly used in skincare for its scent plus a bit of skin conditioning properties.
Lab research credits it with soothing, antioxidant, and wound-supporting effects. This is largely thanks to a compound called rosmarinic acid.
Rosmarinic acid has been shown to calm inflammation signaling in skin cells (the same pathways that flare up in conditions like eczema and psoriasis). It also has real antimicrobial and antifungal activity in test-tube studies.
This ingredient is typically used in low concentrations (generally well under 1%) where it acts as a light fragrance + mild skin soother extract.
The main thing to know is that lavender contains two naturally fragrant molecules: Linalool and Linalyl Acetate. Some people's skin does perfectly fine with fragrance while others don't.
Just be sure to patch test if you have reactive skin or known plant allergies.
Linalool and Linalyl Acetate are gentle when fresh but oxidize into compounds that can cause allergic contact dermatitis when exposed to air. Patch-test studies of patients already being investigated for skin allergies found about 5-7% of patients had reactions to oxidized linalool, and 2.8% of patients reacted to oxidized lavender oil.
Learn more about Lavandula Angustifolia ExtractThymus Vulgaris Flower/Leaf Oil is an oil.
Ethyl Stearate is a fragrance and isn't fungal acne safe.
Pelargonium Graveolens Leaf Oil is an oil.
Tocopherol 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 TocopherolLavandula Oil/Extract is an oil.
Eucalyptus Globulus Oil is an oil.
Geraniol is used to add fragrance/parfum to a product. It is the main component of citronellol. It is a monoterpenoid and an alcohol.
Monoterpenes are naturally found in many parts of different plants.
Geraniol can be found in many essential oils including Rose Oil and Citronella Oil. The scent of Geraniol is often described as "rose-like". Many foods also contain Geraniol for fruit flavoring.
Geraniol can irritate the skin when exposed to air. However, irritation depends on the ability of geraniol to penetrate into the skin. In general, geraniol is not able to penetrate skin easily.
Geraniol is colorless and has low water-solubility. However, it is soluble in common organic solvents.
Like citronellol, it is a natural insect repellent.
2,6-Octadien-1-ol, 3,7-dimethyl-, (2E)-
Learn more about GeraniolGeranyl Acetate is a fragrance. It can cause irritation.
Limonene is a fragrance that adds scent and taste to a formulation.
It's found in the peel oil of citrus fruits and other plants such as lavender and eucalyptus. The scent of limonene is generally described as "sweet citrus".
Limonene acts as an antioxidant, meaning it helps neutralize free radicals.
When exposed to air, oxidized limonene may sensitize the skin. Because of this, limonene is often avoided by people with sensitive skin.
The term 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term. For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance.
Learn more about LimoneneCoumarins are a group of substances found naturally in plants. There are over 1300 types of coumarins identified. It has a natural vanilla scent.
Coumarin is an identified EU known allergy, meaning it may cause an allergic reaction when applied to the skin.
In many countries, coumarin is banned as a food additive. However, it can be found in soaps, tobacco products, and some alcohol drinks.
Plants use coumarins as a chemical defense. Some plants that have coumarins include lavender, tonka beans, and yellow clovers.
Learn more about CoumarinLinalool is a fragrance and helps add scent to products. It's derived from common plants such as cinnamon, mint, citrus, and lavender.
Like Limonene, this ingredient oxidizes when exposed to air. Oxidized linalool can cause allergies and skin sensitivity.
This ingredient has a scent that is floral, spicy tropical, and citrus-like.
Learn more about LinaloolCitronellol is used to add fragrance/parfum to a product. It is often derived from plants such as roses. In fact, it can be found in many essential oils including geranium, lavender, neroli, and more. The scent of Citronellol is often described as "fresh, grassy, and citrus-like".
Since the Citronellol molecule is already unstable, Citronellol becomes irritating on the skin when exposed to air.
Citronellol is a modified terpene. Terpenes are unsaturated hydrocarbons found in plants. They make up the primary part of essential oils.
Citronellol is not able to be absorbed into deeper layers of the skin. It has low permeability,
Citronellol is also a natural insect repellent.
Learn more about CitronellolCitral is the molecule responsible for the fresh lemon scent in lemon, lime, and lemongrass. It is a fragrance ingredient that can be created from plant essential oils or synthetically.
Though Citral has documented antimicrobial activity against acne bacteria (which is where the marketing claims about it being good for acne-prone skin originate), real formulas use it at fragrance-level concentrations under 1% so there's likely no skin benefit.
You should know this ingredient is a known EU fragrance allergen.
Animal studies classifies this ingredient as a weak-to-moderate skin sensitizer and clinical patch testing on eczema patients confirmed it to be both a contact allergen and irritant.
The term 'citral' is a collective term for two geometric isomers: geranial/Citral A and neral/Citral B.
The term 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term. For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance.
Learn more about CitralMenthol is a compound found in mint plants, such as peppermint. In its pure form, it is a clear crystalline substance.
Menthol is known for its cooling sensation; however, the cooling is actually from your skin being sensitized. Menthol can worsen rosacea. We recommend speaking with a professional if you have concerns.
Menthol also has antimicrobial properties.
Learn more about MentholPinene is created by distilling the resin of Pinus trees.
It is a known EU allergen. Long term contact with this ingredient can cause dermatitis.
Linalyl Acetate is the acetate ester of linalool and can be naturally found in many flowers and spice plants.
This ingredient is often used to add a scent or mask an unpleasant one in products.
Linalyl acetate is mildly toxic to humans and toxic to fish.
Learn more about Linalyl AcetateCamphor is a waxy solid with a strong scent. It is made using turpentine oil.
This ingredient is used for medicinal purposes due to its cooling effect. In medicine, camphor is a common anti-inflammation ingredient.
Camphor also possesses antibacterial and antifungal properties.
One study found camphor to be a potential anti-wrinkle ingredient. This might be due to its ability to increase elastin and collagen production. Collagen and elastin are responsible for plump and youthful looking skin.
It is best to use cosmetics with a small amount of camphor under 11%. Using topical camphor may induce irritation and redness.
In the past, camphor was traditionally made by distilling the wood of the camphor tree.
Learn more about CamphorBeta-Caryophyllene is a fragrance. It can cause irritation.
Terpinolene is a fragrance. It can cause irritation.
This ingredient is a fragrance ingredient known for having a fresh, citrus/piney scent.
Though this ingredient has shown antimicrobial activity in lab contexts, it is typically present in low levels in cosmetics.
It is regulated in the EU as an EU allergen. This means it if is present above a threshold, it must be included in the label.
Learn more about Alpha-TerpineneTerpineol is a fragrance. It can cause irritation.
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Where it's from
Yon-ka is a French 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 December 8, 2025 • Added by max8