I never noticed increased weight or bloat on MK but the pumps in the gym were definitely much greater than without. Gains on MK677 may be a little better than natural but I wouldn't expect to gain pounds of muscle in a hurry. I have to concur it's better as an aid to maintain muscle mass with reduced body fat than to build considerable muscle. Seems I was able to hold onto more size at a lower bodyfat % on MK677