What does the serum feel like, and does it leave a sticky finish?

It has a lightweight, watery texture that absorbs quickly and leaves a non-sticky finish.

Is the 13% serum suitable for a vitamin C beginner and everyday use?

Yes. COSRX identifies it as the beginner-friendly option for mild daily brightening and hydration, while the Vitamin C 23 Serum is intended for more experienced users seeking intensive care.

Where does this serum go in my routine, and how much should I apply?

Use it after cleansing and toner. Apply a few drops or a small amount evenly, avoiding the eye area, then gently massage until absorbed.

Can I apply it during the day?

Yes. When you use it during the day, follow with sunscreen.

How should I store the serum after opening?

Keep it away from high temperatures and direct sunlight. Refrigeration is recommended if you do not use it daily and can help maintain freshness. Use the serum within two months of opening.

Is the serum supposed to have a yellow tint?

Yes. The serum has a slight yellow tint from its pure vitamin C content.

Does the serum contain added fragrance or have a noticeable smell?

No fragrance is added. You may still notice a characteristic odor from the formula's raw materials.

How is The Vitamin C 13 Serum different from COSRX's Vitamin C 23 Serum?

The 13% serum is lighter, more refreshing and designed as a mild daily option for beginners. The 23% serum is positioned for experienced vitamin C users seeking more intensive brightening care.