Why is there now a conditioner for the Plantur 21 Nutri-Caffeine Shampoo? Does the shampoo not contain enough conditioning ingredients?

The Plantur 21 Nutri-Caffeine Shampoo contains sufficient conditioning agents for normal use. However, if the hair is very damaged, e.g., due to straightening, blow-drying, highlighting and dyeing, the hair’s scaly layer is not fully closed after it is washed. The Plantur 21 Nutri-Conditioner closes the rough hair structure. The hair's natural shine is restored and can be brushed very easily.