Instead of taking pills I would suggest you to focus on eating a healthy diet for weight gain and also for proper nourishment which you can get only from food. Have a diet consisting of whole grain cereals like whole wheat products, oats, pasta, rice and breads, good quality proteins from milk and milk products like curd/cheese, if non-vegetarian you can include meat/fish/poultry and eggs. Legumes, pulses and beans will also provide proteins in a vegetarian diet. Include fruits and vegetables in your daily diet for vitamins and minerals as you seem to be malnourished due to anorexia. You can have them as vegetable (mixed vegetables like spinach, carrots, tomatoes, beetroot, celery etc.) soups and fruit juices/fruit milkshakes with added sugar/glucose and milk powder for extra energy and proteins also. Have nuts and dried fruits as healthy snacks. They have good fats, vitamins and minerals. Have wholesome foods instead of pills or supplements to ensure you regain health lost due to anorexia. Weight gain pills give results which are temporary and you can t possibly have them forever. So focus on gaining weight through good nourishing foods.