HI, thanks for using healthcare magic You may not need to use pills to gain weight. Persons can gain weight by increasing the amount of calories ( energy in food and drink) that you use. Person lose weight by decreasing the energy input and therefore weight can be gained by increasing energy input. To do this you would need to increase the caloric value of your meals by (1) increasing your portion sizes (2) adding extra cheese, butter, dressings, peanut butter (3) use high calorie snacks such as nuts (4) choose foods that are high in calories like potatoes, avocadoes, fish, poultry, red meat (5) avoid fidgeting, it burns energy (6)start a weight lifting program to build muscle If you wish you can use a multivitamin supplement as well. I hope this helps