Strengthen and moisturize your hair with Nioxin’s three part System 5 Scalp Therapy Conditioner for Chemically Treated Hair with Light Thinning. Nioxin Scalp Therapy System 5 Conditioner 5.07 fl oz. Strengthen and moisturize your hair with Nioxin’s three part System 5 Scalp Therapy Conditioner for Chemically Treated Hair with Light Thinning. Thanks to its Smooth Plex technology, this professional hair care product helps retain moisture balance and provides smoothing control. Lightweight, Nioxin conditioner is specially indicated for chemically treated hair with light thinning and leaves it thicker, fuller-looking. Nioxin’s density-protecting Scalp Therapy Conditioner is the second step of a three part Nioxin regimen, designed to strengthen the hair and amplify hair structure.