The hair, just like the skin, reflects the internal state. Lack of sleep, poor nutrition or a too sedentary life take their toll and affect the hair.
Dryness, product accumulation, environmental factors, chemical damage, nutritional deficiencies and application of inappropriate products are all causes of dull hair. The ideal routine to add shine is a difficult battle because there is no one-size-fits-all approach and it varies due to factors ranging from hair type to environmental humidity or the way you brush.