This listing is included in the 5 for $25 offer. Bundle any 5 listings marked 5 for $25 and send an offer for $25! Sunday Riley A* High Dose Retinod Serum is an advanced-strength serum that delivers a 6.5% blend of retinoids and retinoid alternatives to fight the signs of aging, and improves the look of congested and UV damaged skin, without the drawbacks of traditional retinol. Sample size. See pics with quarter for size comparison. New & unused! 1 LEFT‼️