Yes, you can use the CLINICAL Pro Retinaldehyde Treatment with a nighttime moisturiser. Using a moisturiser or the Moisture Renewal Oil Booster can help minimise potential irritation and dryness caused by retinoids. Applying a moisturiser 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 moisturiser.