Redefine Lip Renewing Serum is usually applied at night to take advantage of inactivity during sleep and helps lips look and feel softer and smoother and visibly younger. Essentials Lip Shield is applied in the morning to moisturize, condition and provide sun protection. If you want to use them both in the morning, allow Redefine Lip Renewing Serum to fully dry before applying Essentials Lip Shield.