# COSRX Brightening Boost

Brightening duo: peptide booster serum plus the brightening serum.

- Brand: COSRX
- Product: Brightening Boost
- Price: $25.99
- Availability: Out of stock
- Made in: Republic of Korea
- Category: Serums & Ampoules

## Key benefits

- The booster component lists six peptide entries, copper tripeptide among them
- Niacinamide and adenosine support a smoother, more even look
- Amino acids and sodium hyaluronate keep the base hydrating

## How it works

Uneven tone and a surface that feels less firm are two problems a single serum often cannot fix alone. This serum lists niacinamide sixth, behind the base humectants, with adenosine and a run of peptides, Copper Tripeptide-1 among them, and sodium hyaluronate in the back half. That combination pairs a tone-evening ingredient with a peptide complex rather than one active alone. Consistent use tends to leave skin looking more even and firmer over weeks rather than days. Apply it on toned skin before moisturizer, with steady daily use.

## How to use

1. Use the Brightening Boost after toner and before moisturizer, morning or evening.
2. A few drops pressed over the face and neck, then left a minute to settle.
3. Toner first, this second, then moisturizer, and sunscreen if it is the morning.
4. Once a day to start. Do not use it in the same routine as an exfoliating acid; give that its own evening.

## Ingredients

Water, Dipropylene Glycol, Glycerin, Pentylene Glycol, 1,2-Hexanediol, Niacinamide, Ammonium Acryloyldimethyltaurate/VP Copolymer, Polyacrylate Crosspolymer-6, Butylene Glycol, Xanthan Gum, Ethylhexylglycerin, Adenosine, Polyquaternium-51, Disodium EDTA, Citric Acid, Caprylyl Glycol, Betaine, t-Butyl Alcohol, Sodium PCA, Sodium Lactate, Acetyl Hexapeptide-8, Copper Tripeptide-1, PCA, sh-Polypeptide-121, Serine, Alanine, Allantoin, Sodium Hyaluronate, Acetyl Glucosamine, Glycine, Glutamic Acid, Lysine HCl, Threonine, Dipeptide Diaminobutyroyl Benzylamide Diacetate, Arginine, Tocopherol, Oligopeptide-68, Proline, Dextran, Palmitoyl Tripeptide-8, Glycine Soja (Soybean) Oil, Hydrogenated Lecithin, Potassium Sorbate, Sodium Oleate

## FAQ

### What is the Brightening Boost serum built around?

Niacinamide sits sixth on the list, behind water, dipropylene glycol, glycerin, pentylene glycol, and 1,2-hexanediol, with adenosine and a run of peptides, including Copper Tripeptide-1, Acetyl Hexapeptide-8, and Oligopeptide-68, further down. Sodium hyaluronate also appears in the back half. That combination describes a niacinamide and peptide serum aimed at tone and a firmer surface look rather than a single-ingredient formula.

### Is this serum suitable for sensitive skin looking for a gentle brightening step?

The list has no fragrance, no essential oil, no added silicone, no paraben, and no mineral oil. That profile suits sensitive skin drawn to a fragrance-free serum built around niacinamide and peptides rather than a stronger acid or retinoid. Anyone managing a diagnosed reactive condition should still check the full ingredient list above against their own known triggers first.

### How long does it take to notice a difference in tone or firmness?

Niacinamide's effect on an even-looking tone and the peptides' role in supporting a firmer surface both build with consistent daily use rather than showing up after a single application. Skin dealing with uneven tone or reduced elasticity tends to change gradually over weeks of steady application, not after one bottle. This list does not declare a percentage for niacinamide, so no specific strength is claimed here.

### Can I layer a brightening or retinoid product with this serum?

This particular list does not include vitamin C or a retinoid, so it functions on its own as a niacinamide and peptide step rather than a base built to carry another active. Applying it after toner and before a separate treatment serum is a reasonable order, but how well a specific brightening or retinoid product pairs depends on that product's own formula. Introduce any new combination slowly.

---

Page: https://korean-pharmacy.com/products/cosrx-brightening-boost