The K-Secret Seoul 1988 Serum is a premium K-beauty facial serum formulated with Retinal Liposome 2% and Black Ginseng Extract. This Costco exclusive duo set includes two 50 ml (1.69 fl oz) pump bottles, providing a generous supply of this highly rated anti-aging treatment.

Retinal — the next-generation form of retinol — works up to 11 times faster than traditional retinol. The encapsulated liposome delivery system enhances ingredient stability and boosts skin absorption for more visible results. The formula targets fine lines, uneven skin tone, and rough texture to leave skin smoother and more radiant.

The Retinal Boosting Complex combines black ginseng extract, bakuchiol, three peptides, and niacinamide to deliver antioxidant-rich support that refines pores, smooths skin texture, and promotes a balanced complexion. Suitable for all skin types including combination, dry, and sensitive skin. Unscented formula for use on face and neck.

For best results, use at night — retinal may oxidize with sun exposure, so daytime use should be followed with sunscreen. Build tolerance gradually by applying twice per week for the first one to two weeks, then increase frequency as skin adjusts. After cleansing and toning, apply an appropriate amount evenly over the face and neck, massage until absorbed, and follow with a moisturizer.