So I use this one at night and the double serum in the morning. It has helped restore my skin, my skin is plumper and the fine lines are all but a memory. It has a slightly lighter feel than the double serum, so I'm thinking of swooping them over? Using the biphase in the morning and the double in the evening, followed up with hydra quench lotion in the morning and brightening cream in the evening, my skin looks so different after only three weeks.