COSRX The 6 Peptide Skin Booster Serum

COSRX The 6 Peptide Skin Booster Serum

Boost hydration, firmness, and overall skin radiance with the COSRX The 6 Peptide Skin Booster Serum, a lightweight toner-like serum designed to help improve the look of fine lines, uneven texture, dullness, roughness, and loss of elasticity. Its fast-absorbing texture makes it an ideal first-step serum for daily use, helping prep the skin for the rest of your skincare routine without stickiness or heaviness.

Formulated with a 6 Peptide Complex, niacinamide, sodium hyaluronate, N-acetylglucosamine, allantoin, and adenosine, this multi-benefit serum helps support smoother, firmer, and more balanced-looking skin. The peptide blend helps target multiple early aging concerns, including elasticity, texture, and visible pores. Niacinamide helps improve the look of uneven tone and supports a brighter-looking complexion, while sodium hyaluronate helps draw in moisture for plumper, more refreshed-looking skin. Allantoin helps comfort the skin, and adenosine helps support a smoother appearance.

The COSRX The 6 Peptide Skin Booster Serum is a great choice for anyone looking for a K-beauty peptide serum, first-step anti-aging serum, or a lightweight Korean skincare serum that helps support hydration, radiance, firmness, and texture all at once. It layers easily under ampoules, serums, and moisturizers, making it a versatile addition to both morning and evening routines.

Size: 150ml / 5.07 fl. oz

Overview

The COSRX The 6 Peptide Skin Booster Serum is a multi-concern daily booster created to help support firmness, radiance, hydration, skin texture, and tone in one step. Designed as a first-step serum, it helps leave skin looking smoother, stronger, and more refreshed while improving the absorption of the next skincare steps.

Study results

According to the brand's reported clinical testing on 20 subjects, this serum showed:

• 162.5% increase in deep moisture
• 76.4% improvement in skin texture
• 40.1% improvement in skin clarity
• 24.5% increase in radiance
• 22.2% improvement in skin density

The brand also states that the formula is primary skin irritation tested, sensitive skin irritation tested, and non-comedogenic tested on acne-prone skin. Individual results may vary.

Key benefits

• Helps improve the look of fine lines and early signs of aging
• Supports smoother-looking skin texture and tone
• Helps boost hydration, radiance, and firmness
• Formulated with 6 peptides, niacinamide, sodium hyaluronate, N-acetylglucosamine, allantoin, and adenosine
• Lightweight, toner-like texture with a non-sticky finish
• Great as a first-step booster in daily skincare routines

How to use

Use after cleansing as a toner step before ampoule, serum, or moisturizer. Dispense a few drops and gently pat over the face until absorbed. Follow with the rest of your skincare routine.

Why we love it

Most serums ask you to choose — hydration or firming, brightening or texture. The COSRX The 6 Peptide Skin Booster Serum doesn't make you pick. Six carefully selected peptides each address a different aging concern in a single first-step formula: collagen support, texture refinement, sebum and pore control, brightening, sensitivity reduction, and fine line smoothing — all layered into one lightweight serum that feels like a toner and absorbs in seconds. The clinical results — 162.5% increase in deep moisture and 76.4% improvement in skin texture — reflect what users consistently report: this is the kind of product that visibly changes how skin looks and feels within weeks, not months. At BestSkincareUSA.com, it's our top first-step serum recommendation from COSRX for anyone building a results-driven Korean skincare routine around multiple aging concerns at once. The 150ml size makes it one of the best-value peptide serums available in all of Korean skincare.

The 6 peptides — what each one does

• SH-Polypeptide-121 — Collagen boosting and plumping — Stimulates collagen production to support a firmer, more volumized-looking complexion and reduce the appearance of fine lines caused by collagen loss over time.
• Copper Tripeptide-1 — Retexturizing — A copper-peptide complex known for its ability to support skin regeneration and improve surface texture, helping skin feel smoother and more resilient with continued use.
• Dipeptide Diaminobutyroyl Benzylamide Diacetate — Excess sebum and pore care — Works to reduce the appearance of enlarged pores and help regulate sebum production, making this serum as effective for oily and combination skin as it is for dry or mature skin.
• Oligopeptide-68 — Brightening — Targets uneven pigmentation and dullness to support a clearer, more radiant-looking complexion — working alongside niacinamide for a compounding brightening effect.
• Palmitoyl Tripeptide-8 — Soothing and sensitivity reduction — Calms reactive or sensitized skin and supports a more comfortable, less reactive skin response — one of the reasons this serum passed primary skin irritation and sensitive skin testing.
• Acetyl Hexapeptide-8 — Fine line smoothing and firmness — A well-researched peptide that helps relax the appearance of expression lines and improve skin firmness, supporting a more youthful-looking contour over time.

Key supporting ingredients

• Niacinamide for tone, barrier support, and oil balance
• Sodium hyaluronate for deep, lasting moisture (contributing to the 162.5% moisture increase)
• N-acetylglucosamine for gentle exfoliation and skin renewal support
• Adenosine for elasticity and smoothing
• Allantoin for skin comfort and soothing
• Natural moisturizing factor (NMF) amino acid complex for barrier reinforcement and long-term skin health

Who it's for

The COSRX The 6 Peptide Skin Booster Serum is suitable for all skin types — oily, combination, dry, sensitive, and mature — and is particularly well-suited for anyone in their late 20s through 50s dealing with early to moderate signs of aging, including fine lines, texture irregularities, dullness, and loss of firmness. Because it's non-comedogenic tested on acne-prone skin and sensitive skin irritation tested, it's one of the most universally appropriate multi-peptide serums in COSRX's lineup. Use it as the first serum step in any Korean face routine and layer targeted treatments on top.

Pro tips and pairings

Because the COSRX The 6 Peptide Skin Booster Serum is designed as a first step, it works best applied immediately after cleansing on slightly damp skin — the toner-like texture spreads more evenly and absorbs faster. Layer it under the COSRX Advanced Snail 96 Mucin Power Essence for an intensive hydration and barrier-repair stack before your moisturizer. For a brightening-focused routine, follow with the COSRX Full Fit Propolis Light Ampoule to build on the oligopeptide-68 brightening effect with a complementary antioxidant layer. At 150ml, this is a generously sized bottle that holds up to consistent daily use for months — exceptional value for a multi-peptide formula at this level.

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