Yes, you can use the CLINICAL Pro Retinaldehyde Dual-Retinoid Treatment with a nighttime moisturizer. Using a moisturizer or the Moisture Renewal Oil Booster can help minimize potential irritation and dryness caused by retinoids. Applying a moisturizer after the retinoid treatment can help to replenish moisture and maintain skin hydration, which is particularly important when using retinoids, as they can sometimes cause dryness and irritation. You can apply your retinoid treatment first then apply your nighttime moisturizer.