Hi Thanks for posting on HCM Weight gain is the desire of many slim people.However, weight gain using weight gainers is not always the best. You need to know that you gain weight when you get more energy from food than what you use for your daily activities.The excess energy will be stored as proteins in muscles and fats in adipose tissues.In order to gain muscle you need calories, 300 to 500 calories more calories than you can burn. Weight gain will however be a progressive process, requiring time, sacrifice and patience.Before resorting to weight gainers, i will advise you try the following measure: -Say Good-bye to Low-Cal -Get on a Regular Eating Schedule -Choose Low-Volume, High-Calorie Foods like Nuts, Nut butters, Dried fruit, Fresh/dense fruits, Starchy vegetables, Healthy oils and fats, Wheat germ and flax meal, -Regular fitness exercises with resistance-training protocol will help you build muscle -Take high energy snacks along with exercise. You may as well see a Nutritionist for better explanation on weight gaining diet. Weight gainers should be the last option. Hope this will help Best regards