I'm reviewing this copper peptide serum that's all the rage in Korea

Visit copper peptides have become one of the hottest anti-aging ingredients right now. And this Korean serum doesn't hold back: it combines 0.5 % of Copper Tripeptide-1 (GHK-Cu), 0.25 % of bakuchiol, niacinamide, and a whole range of peptides.

📌 See also: I'm reviewing Bioderma's Sebium Mat Control cream—what does the Beautydecoded analysis reveal?

On paper, the blue peptide formula from Cosrx is impressive. The brand promises firmer, plumper skin, less visible pores, and even an improvement in dark spots.

A useful clarification right off the bat: when a brand lists «0.5 % of copper peptide,» this figure usually refers to the concentration of a commercial solution, not that of pure GHK-Cu in the finished product.

0.5 % of copper peptide: the number that immediately catches my attention

Visit Copper Tripeptide-1, also known as GHK-Cu, is a peptide that naturally forms complexes with copper.

It is probably one of the most biologically interesting cosmetic peptides. In particular, it is being studied for its role in tissue repair and extracellular matrix remodeling mechanisms.

The second key ingredient: 0.25 % of bakuchiol

The serum also contains 0.25 % of bakuchiol.

It is often referred to as «plant-based retinol,» but that term is a bit misleading.

Bakuchiol is not a retinoid, and its chemical structure is completely different from that of retinol.

Nevertheless, there is some interesting evidence suggesting that it may affect certain mechanisms involved in skin aging and, in particular, improve the appearance of wrinkles and hyperpigmentation.

The association GHK-Cu + bakuchiol is therefore, in my opinion, much more interesting than simply listing a bunch of peptides on the packaging.

And niacinamide ranks very highly

Another great feature: the Niacinamide is listed fifth on the INCI list.

Unlike several peptides listed much further down in the formula, its position suggests that it is used in a truly significant concentration.

A particularly comprehensive moisturizing base

Before we even get to the assets anti-aging, this serum has an excellent moisturizing base.

Very early in the formula, we find:

• Butylene Glycol
• Glycerin
• Dipropylene Glycol
• Betaine

Then further down the panthenol, from beta-glucan and, most importantly, several forms of hyaluronic acid: Sodium Hyaluronate, Hyaluronic Acid, Sodium Hyaluronate Crosspolymer, Hydrolyzed Hyaluronic Acid, and Sodium Acetylated Hyaluronate.

In fact, it contains not just one, but several peptides

In addition to Copper Tripeptide-1, the formula contains:

Diaminobutyroyl Benzylamide Diacetate Dipeptide, often nicknamed Syn-Ake, as well as Acetyl Hexapeptide-1, Acetyl Heptapeptide-4, Acetyl Hexapeptide-8, and Acetyl Octapeptide-3.

The product therefore contains several peptides designed to reinforce its anti-aging benefits.

Can it really tighten pores?

This is probably one of the marketing claims that requires the most nuance.

A cosmetic product does not physically «close» the pores.

On the other hand, several elements of this formula may reduce their appearance.

Hydration and the plumping effect can make the skin’s texture appear more even. Niacinamide may also be beneficial for skin that tends to produce a lot of sebum. So, does this serum deserve its popularity?

So, does this serum deserve its success?

Yes, it's a really good deal.

What I particularly appreciate is that it isn't based solely on a long list of peptides used as a marketing gimmick.

The structure is consistent:

GHK-Cu + bakuchiol + niacinamide + numerous humectants + several complementary peptides.

In my opinion, its main purpose is to combine hydration, plumping effect, and help with visible signs of aging with a light texture.

My verdict

This serum is one of those products where The concept is more compelling than just the passing trend surrounding K-Beauty.

Its main strength, in my opinion, is its versatility : While most copper peptide serums focus entirely on anti-aging, this one combines GHK-Cu with niacinamide and bakuchiol—two active ingredients that also work, albeit more subtly, to even out skin tone and improve the appearance of blemishes.

So while it may not be the most powerful copper peptide serum for anti-aging, it's probably one of the most versatile. It’s important to keep in mind that this effect on blemishes and pores is a fundamental, gradual, and secondary benefit—not the result of a targeted treatment.

Scan your mattifying cream in 3 seconds

A well-placed silica ingredient doesn't tell the whole story about a formula. To find out if your «oily skin» cream is truly lightweight or just mattifies the surface  Download the Beauty Decoded app (iOS and Android) Scan your products, decipher their INCI listings, and compare what the packaging promises with what the formula actually contains.