Have been using the unflavoured marine collagen for several months. The first noticeable improvement was in my skin (I'm 60). Facial skin plumper with fine lines on the face far less noticeable, very happy! Secondly, nails stronger, haven't noticed any improvement in my hair as yet. Am now purchasing on a subscription. My only issue is that the recommended serve is written as 2 teaspoons (10 ml). This is totally inaccurate as using this measure my first container lasted 48 days not 18 days as per the directions. I've found I need to use 2 NZ Tablespoons per day (30 ml). I've discovered a tablespoon is 15ml in NZ, UK, SA, USA. A Australian tablespoon is 20ml. Either way the instructions are misleading. The directions need to reflect a volume relevant to all nations where the product is sold.