Washing hair before bed

Hair growth is most active during sleep, when growth hormones are secreted. Since it is most desirable for the scalp pores to be clean during this time, it is better to wash your hair at night before going to bed rather than in the morning. Additionally, washing your hair in the morning washes away sebum from the scalp, weakening its barrier function and making the scalp more susceptible to direct UV damage. It is advisable to avoid shampooing in the morning during the summer months, when UV damage is more likely to occur.