I have been using this shampoo and conditioner set for 2 years now and my hair still responds to it like the first day I used it. It has made my dry, slighty frizzy hair "soft", silky and smelling wonderful. I always buy the 1 litre bottles (both shampoo and conditioner) because it's cheaper in the long run. If I couldn't use this ever again I may as well chop my hair off!