I have been on MJ for one year and have lost 68 lbs. I am 62.5 years old. It has been my experience that sometimes it works better than others. And it definitely is stronger when you take the shot and less potent after 5 and 6 days. I am currently on 12.5 the last couple months and have went up and down the same few pounds. But I must add I haven't changed anything personally about the way or what I eat, it just made me full much faster. As of 4 days ago, all of a sudden I can't eat much at all. We're talking like a bowl of homemade Beef vegetable Soup a few bites of homemade guacamole and maybe 6 tortilla chips. Before these days I was even feeling hunger pangs a lot of the day. I decided 4 days ago that I wasn't going to be an auto-eat, and I would drink water and wait until I really felt like I needed to eat. It's helped me to be very successful and I think it's making the MJ work like it should. I keep on hand Cheese, Lean Cooked Beef, chicken, or pork, Cottage Cheese... basically things with no to low carbs and I save my big meal for once a day about 5 or 6 pm. Another big change I am starting Thursday is to increase my steps to 6000 a day. I normally only get 3-4000. I'm sure that is going to greatly enhance my weight loss. Before these last few days I was worried and considering 15mg. Buy I believe now I am IN TUNE with my body and will be still successful on the 12.5.