According to Manofmany.com: Shampoo is soap and soap is good. That might lead some men to ask why they can’t use shampoo every day. The answer has to do with the relationship between shampoo and the oils necessary to maintain healthy hair. Every day the scalp produces nourishing oils that keep the hair from drying out. And while these oils aren’t affected by water and moisture (in fact it’s recommended you rinse and exfoliate your hair and scalp daily), they are affected by shampoo. The absence of healthy oils can dry your follicles out at their roots. That means excessive shampooing might keep your hair clean but it will potentially weaken it structurally in the process.
Naturally, there are variables. In fact, when some industry experts were asked how often should men shampoo their hair, they explained that men who use lots of hair product should actually be shampooing more. That’s because too much hair product can lead to clogged pores. Hence, the overuse of shampoo becomes a lesser of two evils whereas it combats the overuse of hair product. Again, this is for men who use lots of hair product. If you’re simply applying a small amount each day, then a solid rinse will take care of it. Meanwhile, men who produce a healthy amount of natural oils and have exceptionally resilient hair should consider cutting their shampoo routine down to just once or twice a week.