The 6 Peptide Skin Booster Serum

COSRX The 6 Peptide Skin Booster Serum is a first-step serum rather than a finishing one. Six peptides in a light, fast-absorbing 150 ml bottle, meant to be spread over the whole face before whatever serum or ampoule you actually came for — so the rest of your routine lands on primed skin.

What it actually does

• Improves several things at once rather than one. COSRX lists pores and sebum, firmness, fine lines, texture, tone and soothing as the areas the six peptides are meant to influence.
• Leaves skin softer and smoother in tone and texture with use, per the brand.
• Absorbs fast and doesn't tack. The texture is described as lightweight and non-sticky, which is what makes it workable as a base layer.
• Built as a booster, not a replacement. COSRX intends it to go on first and be layered several times if you want to amplify the step that follows.
• Brand testing, as stated by COSRX. Dermatologist tested and tested for irritation on sensitive skin, with clinical trials conducted on this serum through Dermacosmetic Skin Science Laboratory Co., Ltd.
• Generous size. 150 ml (5.07 fl oz) — large for a serum, which matters when you're using it as a whole-face first layer.

How to use

1. Cleanse, then reach for this as your opening skincare step.
2. Spread it across the entire face, not just on problem spots — it's a booster layer.
3. Layer it more than once if you want. COSRX says repeat applications can amplify the serum or ampoule that comes next.
4. Follow with your targeted serum or ampoule, then moisturiser.
5. Finish with SPF in the morning.

Is it right for you?

Questions

Is this meant to replace my current serum?

No — it's designed to sit underneath it. COSRX positions it as a first-step booster that pairs with the serum or ampoule you apply afterwards.

What size is the bottle?

150 ml, which is 5.07 fl oz — notably larger than a typical 30 ml serum, because you use it over the whole face.

Has it been tested?

According to COSRX: dermatologist tested, tested for sensitive-skin irritation, and supported by clinical trials run through Dermacosmetic Skin Science Laboratory Co., Ltd. Those are the brand's own claims.

How long does delivery take, and how do I pay?

Delivery takes 3 to 21 working days, depending on availability. Payment options are credit card, debit card, Instapay and mobile wallets — no cash on delivery. See our Shipping Policy.

Can I return it?

For defective, damaged or expired items only, reported within 1 day of delivery. Approved refunds are returned to the original payment method within 15–30 days. See our Return & Refund Policy.