I've only been using MD hair for a couple weeks now. However, after the first wash using the shampoo I could definitely feel a big difference in my hair I just felt thicker and a little bit more volume. Then I used next time before I wash my hair I use the oil and rubbed it all in my scalp and I was really surprised that my hair wasn't oily. I haven't yet used the Marine collagen this so I don't know if it's a sample pack or that's actually what it is I haven't used that yet but I've been using the shampoo and the oil for your scalp for a couple weeks and I only wash my hair like every other day but I definitely feel a difference I think it's a little too soon to notice any like new hair growth or anything but I definitely like it a lot. I'm looking forward to the next few months I'm trying to grow my hair out it's right above shoulder length right now and for the next nine months I'm going to try and let it grow and grow and grow until we go to the Dominican Republic and then I want to get some braids put in my hair! So I'm hoping this product will grow my hair faster and thicker within the next 9 months. I have very fine flat super straight hair that you can't do anything with it and if there's any humidity whatsoever it's going to go flat and straight again and then I just put it up in a ponytail. So I'm really hoping that I really see a big difference I'm already feeling the difference but I want to see the difference!