COSRX The Blue Copper Peptide Bakuchiol Serum, Glow & Plumping

What is this product?

COSRX's Blue Copper Peptide Bakuchiol Serum (50ml) pairs a disclosed 0.5 percent copper peptide with 0.25 percent bakuchiol and five named signal peptides, an oil-free, water-and-silicone formula with no fragrance. The blue naming checks out: copper tripeptide-1 really is there at a meaningful dose. The glow-and-plumping half is plausible rather than proven, since no brand-run test for this exact serum was found, and bakuchiol sits below the concentration most often studied in the literature. A declared ethanol entry midway down the list is worth knowing if drying alcohol is a concern.

What makes it different?

Two independent collagen-relevant mechanisms in one formula, copper tripeptide-1 and bakuchiol, both at disclosed doses, is the structural fact that sets this apart from a single-active peptide serum. Five further signal peptides at ppm-level disclosures back the plumping half of the name further, though none of them comes with a product-specific test result. The formula is entirely oil-free, built on water, glycols and dimethicone, and carries a declared ethanol entry, worth a note for anyone avoiding drying alcohol even though its position in the list suggests a supporting rather than dominant role.

What is in it?

The full ingredient list as the brand publishes it, in the printed order. Each name links to what we know about that ingredient.

This brand publishes its ingredient list in Korean only. Names below are the matching INCI names from the Korean Cosmetic Association ingredient dictionary.

Key ingredientWorth a closer look

• Water
• Butylene Glycol
• Glycerin
• Dipropylene Glycol
• Niacinamide
• 1,2-Hexanediol
• Betaine
• Diethoxyethyl Succinate
• Ammonium Acryloyldimethyltaurate/VP Copolymer
• Dimethicone
• Copper Tripeptide-1
• Polyglyceryl-6 Caprylate
• Polyglyceryl-4 Caprate
• Bakuchiol
• Hydrogenated Lecithin
• Alcohol
• Sodium Methyl Stearoyl Taurate
• Ethylhexylglycerin
• Hydroxypropyl Starch Phosphate
• Disodium EDTA
• Adenosine
• Caprylyl Glycol
• Tocopherol
• Dipeptide Diaminobutyroyl Benzylamide Diacetate
• Acetyl Hexapeptide-1
• Acetyl Heptapeptide-4
• Panthenol
• Inositol
• Acetyl Hexapeptide-8
• Sodium Hydroxide
• Propanediol
• Beta-Glucan
• Sodium Hyaluronate
• Hyaluronic Acid
• Sodium Hyaluronate Crosspolymer
• Hydrolyzed Collagen
• Hydrolyzed Hyaluronic Acid
• Sodium Acetylated Hyaluronate
• Acetyl Octapeptide-3

Ingredients with no mark are ones we found nothing notable about, and when marks overlap on one ingredient we show the caution first.

We could not place these in the list above: 폴리글리세릴-6카프릴레이트, 폴리글리세릴-4카프레이트, 하이드로제네이티드레시틴, 소듐메틸스테아로일타우레이트

Did the ad claims hold up?

We checked 2 lines this product advertises against the ingredient list and public documents. One of them holds up. The rest are only partly right or have nothing behind them.

Claims translated from Korean, originals preserved.

Each line is quoted as the brand published it, and each one was read on its own against the ingredient list and the documents the brand publishes.

How we read these lines

Which articles cover it?

Articles on this site that write about this product.

• Bakuchiol or retinol: the gentle one is the one you cannot checkRetinoid labels print a level 19 times out of 34. Bakuchiol labels print one twice out of 19. That asymmetry decides which of the two you can shop for.
• Peptides on a Korean label, and the billion fold range between themFive Korean products that print every peptide level they hold. The highest is half a percent and the lowest is two thousandths of a part per billion.