If your skincare wishlist includes plumper-looking skin, a healthy glow and a little anti-aging magic, this K-beauty serum deserves a spot on your radar.

I’ve been testing K-beauty products for years upon centuries at this point (and have tried most of what COSRX has to offer), so I’m always interested when the brand comes out with something that combines multiple buzzy skincare ingredients in one formula.

Enter the COSRX The Blue Copper Peptide Bakuchiol Plump Glow Serum, a multitasking treatment that brings together peptides, bakuchiol and skin-loving hydrators for what sounds like a pretty dreamy complexion cocktail.

And the best part? You can find it for under $20 on Amazon, making it an especially tempting addition to an already well-stocked skincare shelf.

Let’s talk ingredients, because this formula has quite a bit going on. First up is copper tripeptide-1 (GHK-Cu), a popular ingredient in the anti-aging skincare conversation. Copper peptides are prized for their ability to support skin’s natural repair processes and help improve the appearance of firmness and elasticity. In other words, they’re a great ingredient to look for when you’re after skin that looks smoother, bouncier and more resilient.

Then there’s bakuchiol, a plant-derived ingredient often described as a gentler alternative to retinol. It’s loved for its potential to improve the appearance of fine lines, uneven texture and other early signs of aging, without the same reputation for irritation that can come with traditional retinoids. The combination of these two ingredients makes this serum particularly interesting for anyone looking to get more out of their daily routine.

But COSRX doesn’t stop there. The formula also features a five-peptide complex, collagen, five types of hyaluronic acid, niacinamide and panthenol. That’s a pretty impressive supporting cast. Hyaluronic acid helps attract and retain moisture, giving skin a fuller, more hydrated appearance, while niacinamide helps improve the look of uneven tone and texture. Together, these ingredients make the serum about more than just anti-aging: It’s also designed to deliver that coveted fresh, dewy, glass-skin finish.

I haven’t personally put this particular serum through its paces just yet, but COSRX is a brand I’ve come back to time and again throughout my K-beauty explorations. And clearly, shoppers are paying attention, too. The Amazon listing has been attracting at least 10,000 monthly purchases, which is no small feat for a skincare product.

My take? If you’ve been curious about copper peptides, want to explore bakuchiol or simply love a multitasking serum that prioritizes hydration and glow, this under-$20 COSRX find is worth adding to your K-beauty wishlist. Sometimes the best skincare cocktail doesn’t require a luxury price tag.

What does COSRX The Blue Peptide Bakuchiol Serum do?

It’s a daily anti-aging serum that improves elasticity, fine lines and radiance using 0.5% copper tripeptide-1 and 0.25% bakuchiol.

Why is the serum blue, and does it have dyes?

The natural blue color comes directly from copper tripeptide-1. The formula contains no synthetic dyes, artificial colorants or added fragrances.

How does bakuchiol compare to traditional retinol?

Bakuchiol delivers similar firming and texture-smoothing benefits as retinol without causing typical redness, peeling or sun sensitivity.

How should this serum be applied in a routine?

Apply one to two pumps daily to clean skin before heavier creams. Always follow with sunscreen during the daytime.

Can it be layered with vitamin C or exfoliating acids?

Avoid mixing copper peptides directly with strong vitamin C or AHA/BHA acids. Use acidic products in the morning and this serum at night.

What is the return policy and warranty for this product?

Purchases via Amazon follow standard 30-day return policies. COSRX does not provide a separate extended manufacturer warranty for cosmetics.

This article was written by Victoria McDonnell, New York Post Commerce Journalist & Content Strategist, who has spent countless hours researching, testing hundreds of products and comparing the latest makeup, skincare, hair and beauty items and trends to determine what’s truly worth your hard-earned cash. She evaluates formulas, textures, ingredients and more, in addition to consulting medical and industry experts. Some of Victoria’s latest conquests include testing the best sheet masks on the market, and a rinse-and-repeat review of the best shampoos for all hair types and budgets. Victoria, who received a beauty industry essentials certification from the Fashion Institute of Technology, has been creating shopping guides for the New York Post since 2021 and previously held positions at Insider Reviews and CNN Underscored.