To learn more about Oak Essentials, visit OakEssentials.com. Nightly Retinol Serum: Remove pump/dropper from bottle. Pump/squeeze any remaining product from the pump/dropper and rinse thoroughly. Rinse the inside of the bottle with warm water to remove any visible product formula. Dispose of each packaging component (unassembled) into your recycling bin or drop off at your local recycling center.