My Signature C Source delivers a multitude of complexion benefits for beautifully healthy skin. Pure Vitamin C fine, brighten, balance, and tone skin for a radiant appearance. | [How to use] After cleansing and toning, apply 2-3 drops gently all over face everyday night as Serum. Applying sunblock is essentially needed during daytime. Slight stimulus may be experienced at the first time to use Vitamin C serum. Mixing with several drops of serum and toner makes your skin refresh without sticky feeling. After absorption, follow with appropriate lotion and cream.