This is from Mary
'I am trying to fix my issue with severe dry hair. After I deep condition my hair, it is ok for 2-3 days but after that there is nothing that I can do apart from washing my hair all over again that will give it moisture. I do use a leave in conditioner after the deep condition but moisturisers do not seem to work at all for me. Can you recommend some products?'
A: In my view there is no difference between a leave in and a moisturiser. The purpose of a leave in is to add ingredients that improve the humidity around the hair (humectants such as glycerin, aloe vera etc and water) and ingredients to help seal in that moisture (oils, silicones etc). This is what a moisturiser would also contain.
My question would be why not just wash your hair after 2 days if that help you retain moisture?
The lesson: Leave ins and moisturisers are essentially very light conditioners. If your hair needs a heavy conditioner (ie rinse out conditioner, conditioning mask or deep conditioner) to feel moisturised, why not use them?