Yolu (or "yoru") means "night" and this is exactly the concept behind the YOLU Calm Night Repair Shampoo & Treatment: two items that take care of your hair and scalp, while you're asleep. All you have to do is use the shampoo like a regular shampoo (wet your hair, apply some, lather well, wash, and rinse thoroughly) and then apply the treatment from the middle of your hair's to the ends, and rinse until you can feel the hair becoming smooth.
