Should I apply it in the morning, at night, or both?

COSRX recommends this serum twice daily, so it fits both morning and evening routines. In the morning, follow it with moisturizer and sunscreen. At night, continue with any compatible active and your usual cream. Start with one daily application if your routine already contains several active products, then increase only if your skin stays comfortable.

Can I use the peptide booster with vitamin C?

Yes. Apply the peptide booster first and let it absorb before your vitamin C serum, moisturizer, and morning sunscreen. COSRX specifically presents the two as a compatible pairing. When combining products for the first time, introduce one change at a time so you can tell which formula is responsible if your skin feels uncomfortable.

Can I use it with retinol?

Yes, it can be used before retinol because the watery booster is the lighter layer. Follow with your retinol product and moisturizer according to that product's directions. If your skin is sensitive or your retinol is new, begin on alternate nights and patch test rather than adding several unfamiliar steps at once.

Is it a toner or a serum?

It sits between the two formats: COSRX calls it a serum, but the thin texture and first-step directions let it work like a toner. You do not need another toner for the routine to be complete. Keep one only if you enjoy it and the extra layer feels comfortable on your skin.

Is it suitable for sensitive or acne-prone skin?

COSRX says the formula was tested for primary irritation, sensitive-skin irritation, and non-comedogenic use on acne-prone skin. That supports broad suitability, not a promise that every person will react the same way. Patch test first, avoid the eye area if it stings, and stop if persistent redness or discomfort develops.

How much should I use?

Use two to three pumps for a light, even layer across the face. Pat rather than rubbing until the watery serum disappears into the skin. COSRX also allows another thin layer when you want more hydration, but a heavier application is not necessary for the booster to sit correctly beneath the rest of your routine.

How long does it take to see results?

COSRX says visible changes are typically noticed after about four weeks of consistent use. Its published clinical findings cover moisture, texture, clarity, radiance, density, and a smoother, more supple feel; the complete figures appear in Real Results below. The practical expectation is gradual refinement, not an overnight transformation from one lightweight layer.

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COSRX

COSRX The 6 Peptide Skin Booster Serum 150ml

Hydrating
Smooths
Brightening
Lightweight

150ml ·$16.99 USD

Hydrating

Smooths

Brightening

Lightweight

PRODUCT DETAILS

COSRX The 6 Peptide Skin Booster Serum is a watery, toner-like serum used immediately after cleansing. Its quick-absorbing texture gives skin an early layer of moisture while helping it feel smoother and look more refreshed, without the weight of a traditional serum. The 150ml pump bottle is designed for daily use, morning or night, before essences, ampoules, moisturizers, or sunscreen.

Six peptides sit alongside niacinamide, adenosine, sodium hyaluronate, allantoin, N-acetylglucosamine, and amino acids. Together, the formula is built around visible texture, radiance, firmness, hydration, and the appearance of pores. Natural moisturizing factors help draw water toward the skin's surface, while the lightweight base layers cleanly under richer steps.

This is a flexible choice for normal, dry, oily, combination, or sensitive skin, especially when dullness, dehydration, rough texture, visible pores, or early fine lines are the concern. It works best as a prep step rather than a rich standalone layer, so very dry skin should still follow with moisturizer. COSRX reports measured improvements across moisture, texture, clarity, radiance, and density in testing of this exact serum; steady use matters more than expecting an overnight transformation.

Learn more

GOES WELL WITH

100 Reedle Shot Stick Pouch$8.09 USD

1025 Dokdo Cleanser$11.99 USD

1025 Dokdo Eye Cream$22.99 USD

1025 Dokdo Lotion$14.99 USD

1025 Dokdo Sleeping Pack$15.99 USD

1025 Dokdo Sun Cream$18.99 USD

1025 Dokdo Cream$24.99 USD

1025 Dokdo Pad$20.99 USD

A light first layer that brings together hydration, smoother texture, brighter tone, and firmness-focused care without heaviness.

Deep, weightless hydration
Smoother-looking texture
Brighter, clearer finish
First-step flexibility
Firmness-focused care

Key Ingredients

Niacinamide

Helps visibly brighten uneven tone and support the skin barrier.

A blush paper ribbon curves across an ivory platform with a pale lavender panel behind.

Peptides

Some exact peptide forms may support smoother, firmer-looking skin; evidence varies by peptide and formula.

Clear hydrogel spheres and droplets on a pale lilac background.

Hyaluronic Acid

Helps hydrate and visibly plump the skin.

Real Results

162.5%Increase in deep moisture¹
76.4%Improvement in skin texture¹
100%Reported smoother, more supple skin¹
40.1%Increase in skin clarity¹
24.5%Increase in visible radiance¹

View all 6 real results

Clear COSRX 6 Peptide Skin Booster bottle with a black pump, white label, and transparent background.

Concerns & Benefits

Your Concerns

1
Dehydration
Skin drinks in each layer yet still feels tight or looks flat before the day is over.
2
Texture
A rough, uneven surface that catches light and makes makeup sit less smoothly.

How To Use

1Use morning and evening on freshly cleansed skin, before heavier leave-on products.
2Pump two or three doses into clean palms.
3Sweep a light layer over the face and press gently until the fluid settles. Keep it away from the eyes if that area is easily irritated.
4Add a second thin layer only when extra moisture feels useful.
5Continue with ampoule or serum, then moisturizer. End daytime routines with sunscreen. Introduce unfamiliar active combinations one at a time. Discontinue use if ongoing burning, redness, or discomfort develops.

Frequently asked questions

Where does the COSRX 6 Peptide Skin Booster go in a routine?

Use it immediately after cleansing, before thicker essences, ampoules, serums, and moisturizer. Its toner-like texture is meant to be the first leave-on layer, so it can replace a traditional toner when you want a shorter routine. If you enjoy using both, apply the thinner product first and let each layer settle before continuing.

Customer reviews

Frequently Bought Together

Buy these products together

This itemCOSRX The 6 Peptide Skin Booster Serum 150ml$16.99 USD

100 Reedle Shot Stick Pouch$8.09 USD

1025 Dokdo Cleanser$11.99 USD

Total price: $37.07 USD

This itemCOSRX The 6 Peptide Skin Booster Serum 150ml$16.99 USD

100 Reedle Shot Stick Pouch$8.09 USD

1025 Dokdo Cleanser$11.99 USD

Total price: $37.07 USD

VT COSMETICS

100 Reedle Shot Stick Pouch

A travel-size evening booster for smoother-feeling, more refined-looking skin.

2 mL × 10$8.09 USD

ROUND LAB

1025 Dokdo Cleanser

Creamy, slightly acidic foam for a comfortable cleanse

150 ml$11.99 USD

ROUND LAB

1025 Dokdo Eye Cream

Lightweight daily eye care for hydration, brightness and smoother-looking fine lines.

30 ml / 1.01 fl oz$22.99 USD

ROUND LAB

1025 Dokdo Lotion

A lightweight, unscented facial moisturizer with three forms of hyaluronic acid for lasting moisture without stickiness.

200 ml$14.99 USD

ROUND LAB

1025 Dokdo Sleeping Pack

A lightweight, unscented overnight gel for hydration and smoother-feeling skin.

100 ml$15.99 USD

ROUND LAB

1025 Dokdo Sun Cream

SPF 50+ PA++++ protection in a lightweight, no-white-cast lotion.

50 ml$18.99 USD

ROUND LAB

1025 Dokdo Cream

A rich, unscented balm moisturizer for lasting hydration and a soft, cushioned feel.

80 ml$24.99 USD

ROUND LAB

1025 Dokdo Pad

Two-sided toner care for tidier texture and balanced moisture.

70 pads / 120 g$20.99 USD

COSRX 6 Peptide Skin Booster Serum 150ml | Sleepy Hello

COSRX

COSRX The 6 Peptide Skin Booster Serum 150ml

Hydrating
Smooths
Brightening
Lightweight

COSRX The 6 Peptide Skin Booster Serum 150ml

150ml ·$16.99 USD

Hydrating

Smooths

Brightening

Lightweight

PRODUCT DETAILS

Learn more

GOES WELL WITH

100 Reedle Shot Stick Pouch$8.09 USD

1025 Dokdo Cleanser$11.99 USD

1025 Dokdo Eye Cream$22.99 USD

1025 Dokdo Lotion$14.99 USD

1025 Dokdo Sleeping Pack$15.99 USD

1025 Dokdo Sun Cream$18.99 USD

1025 Dokdo Cream$24.99 USD

1025 Dokdo Pad$20.99 USD

A light first layer that brings together hydration, smoother texture, brighter tone, and firmness-focused care without heaviness.

Deep, weightless hydration
Smoother-looking texture
Brighter, clearer finish
First-step flexibility
Firmness-focused care

Key Ingredients

Real Results

162.5%Increase in deep moisture¹
76.4%Improvement in skin texture¹
100%Reported smoother, more supple skin¹
40.1%Increase in skin clarity¹
24.5%Increase in visible radiance¹

View all 6 real results

Concerns & Benefits

Your Concerns

1
Dehydration
Skin drinks in each layer yet still feels tight or looks flat before the day is over.
2
Texture
A rough, uneven surface that catches light and makes makeup sit less smoothly.

How To Use

1Use morning and evening on freshly cleansed skin, before heavier leave-on products.
2Pump two or three doses into clean palms.
3Sweep a light layer over the face and press gently until the fluid settles. Keep it away from the eyes if that area is easily irritated.
4Add a second thin layer only when extra moisture feels useful.
5Continue with ampoule or serum, then moisturizer. End daytime routines with sunscreen. Introduce unfamiliar active combinations one at a time. Discontinue use if ongoing burning, redness, or discomfort develops.

Frequently asked questions

Where does the COSRX 6 Peptide Skin Booster go in a routine?

Customer reviews

Frequently Bought Together

Buy these products together

This itemCOSRX The 6 Peptide Skin Booster Serum 150ml$16.99 USD

100 Reedle Shot Stick Pouch$8.09 USD

1025 Dokdo Cleanser$11.99 USD

Total price: $37.07 USD

This itemCOSRX The 6 Peptide Skin Booster Serum 150ml$16.99 USD

100 Reedle Shot Stick Pouch$8.09 USD

1025 Dokdo Cleanser$11.99 USD

Total price: $37.07 USD

VT COSMETICS

100 Reedle Shot Stick Pouch

A travel-size evening booster for smoother-feeling, more refined-looking skin.

2 mL × 10$8.09 USD

ROUND LAB

1025 Dokdo Cleanser

Creamy, slightly acidic foam for a comfortable cleanse

150 ml$11.99 USD

ROUND LAB

1025 Dokdo Eye Cream

Lightweight daily eye care for hydration, brightness and smoother-looking fine lines.

30 ml / 1.01 fl oz$22.99 USD

ROUND LAB

1025 Dokdo Lotion

A lightweight, unscented facial moisturizer with three forms of hyaluronic acid for lasting moisture without stickiness.

200 ml$14.99 USD

ROUND LAB

1025 Dokdo Sleeping Pack

A lightweight, unscented overnight gel for hydration and smoother-feeling skin.

100 ml$15.99 USD

ROUND LAB

1025 Dokdo Sun Cream

SPF 50+ PA++++ protection in a lightweight, no-white-cast lotion.

50 ml$18.99 USD

ROUND LAB

1025 Dokdo Cream

A rich, unscented balm moisturizer for lasting hydration and a soft, cushioned feel.

80 ml$24.99 USD

ROUND LAB

1025 Dokdo Pad

Two-sided toner care for tidier texture and balanced moisture.

70 pads / 120 g$20.99 USD