I've been using this in conjunction with the Jack Black True Volume Thickening shampoo.  First of all, I have had thinning hair since I was about 26, going on ten years now.  I've tried all kinds of products to try and magically make my hair appear thicker and fuller, but I have finally come to the acceptance that there is no miracle product.  With that said, I believe this is a great conditioner.  It is relatively light, has pleasant citrus smell (smell is subjective), and it leave my hair very soft and manageable.  I'm not going to say one way or the other whether this has made my hair appear thicker... if it has, it's barely noticeable.  But since I keep my hair relatively short, it has made it much more manageable.  I will buy this product again.