Is it better to use the full K18 routine?

Yes, it is better to use the full K18 routine for optimal service and molecular repair results.
To achieve the best cumulative results, we recommend using these routines: 

• When you need to repair damage: detox shampoo + mask
• When you need to protect against daily damage:DAMAGE SHIELD shampoo + conditioner
  every day: molecular repair hair oil
• Between wash days: AirWash™ dry shampoo
• Before K18 molecular repair mask, our PEPTIDE PREP™ detox shampoo tackles buildup + metals to create the cleanest, healthiest hair canvas. With our molecular repair formulas, you get maximum damage repair plus additional styling benefits with the oil. 
• Use the DAMAGE SHIELD shampoo + conditioner to protect hair from daily damage between K18 mask days–and keep healthy hair going in-between salon appointments. Use AirWash™ dry shampoo to refresh hair between washes with an instant, weightless clean.