It is suggested to use a pea sized amount of shampoo with water and massage into ends of hair and scalp. I have to use at least a quarter size of shampoo for it to cover my hair. It does partially lather well. It doesn’t have a great amount of lather but it still covers my hair just fine. It’s not suggested but I do leave it on my hair for a couple of minutes before rinsing. I like to allow some time for the product to soak in. I do follow with the matching conditioner which is great also. The main ingredients help to stimulate hair growth and strengthen the strands of my hair. Being free of harsh chemicals will also help stimulate hair growth. I feel that this shampoo in conjunction with the matching conditioner has made my scalp and hair healthier. I can tell a big difference in the way the strands of my hair feels. It will take time for me to see hair growth of course but I believe this set is the right combination for my thinning hair.