Nioxin System 6 is great for noticeably thinning natural 4b/c hair. A couple of years ago my edges were badly damaged from wearing poorly installed extensions. I started going to a new hairdresser (Calvina Strothers of Gaude and Gold) and she recommended this product. I tried it for a month and took Biotin supplements and used Profectiv Mega Growth and my edges grew at least 1-2 inches. I swear by this product. Nioxin comes in several systems so you can use a different number system if you have relaxed or fine hair or if your thinning is not as severe. Go to nioxin.com and it will ask you a series of questions about your hair and it will help to find the right system number for you. Nioxin ranges from $30-$80 depending where you purchase it from. It is a lot cheaper to purchase this product online than to purchase it at professional salons.