Replenix All-Trans-Retinol Smoothing Serum 3X - 1 fl oz by Replenix. Save 13 Off!. $55.40. Smooth, firm, and clear your skin all at the same time. Replenix Retinol Smoothing Serum 3x is strong enough to clear your skin of acne blemishes and reduce signs of aging, yet wont irritate or dry out your normal skin.