0.5% Retinol Serum

cos.kim

Where to buy Possibly in stock

About this product

The cos.kim 0.5% Retinol Serum is a serums, essence, ampoule. Our analysis of its 13 ingredients (11 low-risk) rates it Excellent (89/100). Based on its ingredients, it looks well-suited to oily / acne-prone and dry skin.

Vegan-friendly Reef-safe

Summarised from our ingredient analysis — not brand marketing copy.

At a glance

Type
Serums, Essence, Ampoules
Ingredients
13
Low-risk
11
Fragrance
Fragrance-free
Origin
Türkiye
Data updated
May 2026

The evidence

Quick Product Notes

Paraben-Free Sulfate-Free Alcohol-Free Silicone-Free EU Allergen-Free Fungal Acne (Malassezia) Safe Minimal Ingredients

Notable Effects & Ingredients

No Notable Effects & Ingredients

Ingredients Related to Skin Types

Good   Bad — tap a skin type to see which ingredients · estimated from ingredient functions
Dry Skin 3/2
Good for dry skin
Acetyl Hexapeptide-8 Sodium Hyaluronate Hyaluronic Acid
Caution for dry skin
Xanthan Gum Polysorbate 20
Oily/Acne-Prone Skin 1/0
Good for oily/acne-prone skin
Retinol
Sensitive Skin 1/2
Good for sensitive skin
Allantoin
Caution for sensitive skin
Phenoxyethanol Retinol

Ingredients list

13 total
Lower hazard (1) Higher hazard (9)
All13 Skin Conditioning14 Humectant3 Hair Conditioning2 Skin Protecting2 Viscosity Controlling2 Antistatic Agent2 Viscosity Increasing Agent2 Emulsion Stabilising2
EWG CIR Ingredient Name & Cosmetic Functions Notes
1
Water
(Solvent)
1
A
Niacinamide
(Hair Conditioning, Skin Conditioning, Smoothing)
9
A
Retinol
(Skin Conditioning)
Bad for Sensitive Skin
Bad for Sensitive Skin
3
B
Polysorbate 20
(Emulsifying, Surfactant)
Fungal Acne
Fungal Acne Trigger
1
A
Sodium Hyaluronate
(Skin Conditioning, Humectant)
Good for Dry Skin
Good for Dry Skin
1
Acetyl Hexapeptide-8
(Humectant, Skin Conditioning)
1
A
Panthenol
(Antistatic Agent, Hair Conditioning, Skin Conditioning)
Good for Dry Skin
Good for Dry Skin
1
A
Hyaluronic Acid
(Skin Conditioning, Viscosity Increasing Agent, Antistatic Agent, Humectant, Moisturising)
1
A
Ethylhexylglycerin
(Deodorant, Skin Conditioning)
4
A
Phenoxyethanol
(Fragrance, Preservative)
Paraben
Paraben
1
A
Xanthan Gum
(Binding Agent, Emulsion Stabilising, Skin Conditioning, Surfactant Emulsifying Agent, Viscosity Increasing Agent, Binding, Gel Forming, Viscosity Controlling)
1
A
Allantoin
(Skin Conditioning, Skin Protecting, Soothing)
Good for Oily Skin
Good for Oily Skin
Good for Sensitive Skin
Good for Sensitive Skin
1
A
Disodium EDTA
(Chelating Agent, Viscosity Controlling)

My Ingredient Notes

No personal ingredient notes yet. Save ingredients to your profile to get good/bad alerts here.

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No close formula match yet — browse other products like this

Key ingredients

Antioxidants
Shields skin from free radical damage.
Retinoid
Visibly reduces the signs of aging.
Vitamin E
Protects skin and soothes irritation.

Benefits

HydratingBoosts hydration and relieves dry, tight skin.
Reduces IrritationEases discomfort and supports skin resilience.
Redness ReducingSoothes visible redness and calms irritation.
Scar HealingImproves the look of marks and scars.
Barrier RepairStrengthen and restore your skin's natural barrier.
BrighteningRestores radiance to dull, tired skin.
Good For Oily SkinBalances oil and helps reduce shine.
Anti-AgingSoftens lines and helps skin look youthful.

Concerns

Contains paraben
Not fungal acne (malassezia) safe
Retinol — higher EWG
May not suit sensitive skin

EWG flags hazard, not real-world risk — ratings don't account for how much of an ingredient a product contains. Treat these as things to research, not verdicts. How we score →

Ingredients explained

Water
Solvent
Low-hazard ingredient.Read moreShow less
EWG 1 Solvent
Niacinamide
Hair conditioning, Skin conditioning
Low-hazard ingredient.Read moreShow less
EWG 1 CIR A Hair conditioningSkin conditioningSmoothing
Acetyl Hexapeptide-8
Humectant, Skin conditioning
Low-hazard ingredient.Read moreShow less
EWG 1 HumectantSkin conditioning
Hyaluronic Acid
Skin conditioning, Viscosity increasing agent
Low-hazard ingredient.Read moreShow less
EWG 1 CIR A Skin conditioningViscosity increasing agentAntistatic agentHumectantMoisturising
Ethylhexylglycerin
Deodorant, Skin conditioning
Low-hazard ingredient.Read moreShow less
EWG 1 CIR A DeodorantSkin conditioning
Xanthan Gum
Binding agent, Emulsion stabilising
Low-hazard ingredient.Read moreShow less
EWG 1 CIR A Binding agentEmulsion stabilisingSkin conditioningSurfactant -emulsifying agentViscosity increasing agentBindingGel formingViscosity controlling
Disodium EDTA
Chelating agent, Viscosity controlling
Low-hazard ingredient.Read moreShow less
EWG 1 CIR A Chelating agentViscosity controlling
Retinol
Skin conditioning
Potentially a skin irritantRead moreShow less
EWG 9 CIR A Skin conditioning Bad for Sensitive Skin
Polysorbate 20
Emulsifying, Surfactant
Low-to-moderate hazard.Read moreShow less
EWG 3 CIR B EmulsifyingSurfactant Fungal-acne trigger
Sodium Hyaluronate
Skin conditioning, Humectant
Low-hazard ingredient.Read moreShow less
EWG 1 CIR A Skin conditioningHumectant Good for Dry Skin
Panthenol
Antistatic agent, Hair conditioning
Low-hazard ingredient.Read moreShow less
EWG 1 CIR A Antistatic agentHair conditioningSkin conditioning Good for Dry Skin
Phenoxyethanol
Fragrance, Preservative
Low-to-moderate hazard.Read moreShow less
EWG 4 CIR A FragrancePreservative Paraben
Allantoin
Skin conditioning, Skin protecting
Low-hazard ingredient.Read moreShow less
EWG 1 CIR A Skin conditioningSkin protectingSoothing Good for Oily SkinGood for Sensitive Skin

How to use

How to use

  • 1 Where it fits: Apply after toner and before moisturiser — thinnest to thickest.
  • 2 Evening: Use at night — start 2–3× a week and build up as your skin tolerates it.
  • 3 Wear SPF the next day: Acids and retinoids increase sun sensitivity — daily sunscreen is a must while using this.

General guidance from this product's category and active ingredients — always follow the directions on the package.

Trust & honesty

Pregnancy & breastfeeding

Contains ingredients some choose to avoid or double-check while pregnant or nursing.

Often avoided
Retinoids (Vitamin A) (Retinol)

Topical retinoids (retinol, retinaldehyde, retinyl esters) are widely advised against in pregnancy as a precaution. The strongest evidence is for ORAL retinoids; topical absorption is low, but most clinicians err on the side of caution.

This is general information, not medical advice. Pregnancy guidance varies and depends on concentration and your individual situation — always check with your doctor, midwife or pharmacist. How we flag this.

Effective levels — general guide

The concentrations these actives are typically effective at in research — not a measurement of this product.

Retinoids (Vitamin A) 0.01–1%

Most studied between 0.1% and 1%. Higher is not automatically better — irritation climbs with dose, so a well-formulated lower strength is often the sweet spot.

Retinol

Niacinamide 2–5% (up to 10%)

Most research uses 2–5%; some formulas go to 10%. Very high levels can cause flushing in sensitive skin.

Niacinamide

INCI lists don't disclose amounts, and we don't claim to know this product's levels — these are the ranges these ingredients are usually effective at, so you can tell a real formula from "fairy-dusting" a marketed active. How we estimate this.

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