I have been using this product for 4 years after trying many other weight gainers/protein supplements and seeing very little weight gain. I am very skeptical of most products in the market, so I want to share my experience with this product.I am 27 years old, 6'3" and my body weight without exercise and lifting is 154 pounds. My metabolism is through the roof and I have a hard time putting on weight no matter how much I lift or eat. I tried a few different products to supplement working out (I mostly lift high weight, low to medium reps) and never had much success. With heavy lifting I could get to 168 pounds or so but could never break past that point.After trying Russian Bear 4 years ago, I noticed that I was gaining weight pretty quickly without changing my workouts. I bought a second jug and by the end of it I had put on another few pounds. Not only that, but I was feeling stronger, lifting more, and even eating more. I would take 2 scoops with about 24 ounces of whole milk after every workout, 1 scoop with 14 ounces of whole milk every morning, and half a scoop with 8 ounces of whole milk before bed (important to not go to bed on an empty stomach). Using this routine, I haven't found a legal product that can put more weight on me. I don't lift or take Russian Bear from April-October, and my weight ALWAYS goes back to 154 pounds by November when I begin lifting again. With the help of Russian Bear, I am able to go from 154 up to 182 pounds in a 4 month lifting cycle. Before Russian Bear I couldn't rise above 168 no matter how hard I worked at at, now I can make it 14 pounds above that mark over the same time frame. It should be noted that my fat % stays consistently around 6%, so I do not gain fat while taking the product. Russian Bear gives my muscles the extra fuel they need to build mass, without putting fat on me.Many people make the point that you should just eat more and bigger meals in combination with weight lifting if you want to gain healthy weight. I agree with this, but I cannot control my hunger levels. There is only so much I can eat in a day without making myself sick. This shake goes down easy after a meal, and allows me to maximize my caloric intake, something I really need with my high metabolism. I eat like I always have, and the shakes are the bonus that gets me over the hump.I recommended this product to 2 friends who trusted my advice, both had success and liked the taste/consistency of the product. I will continue to recommend and use this product as long as it is available. I have only had Russian Bear in chocolate, I like it so well I don't have any interest in trying another flavor.* The only downside to this product is the recommended serving size is absurd, so the advertised calories per serving are very skewed. I have noticed no gain in fat from using Russian Bear, but my metabolism is not normal. An average weighted or heavier person might want to avoid this product altogether, or just take a scoop after a heavy workout. Cytogainer is another great protein supplement, with low fat intended for building lean muscle mass, individuals that gain fat easily should look in that direction. *