Protein powders are expensive & have many additives. Try incorporating natural sources instead. Long term high protein intake can damage kidneys. Your total protein requirement will vary with duration, type & intensity of workout. For healthy weight gain without any side effects you may follow these simple & inexpensive tips.
1. Have frequent meals at 2-3 hrs intervals rich in nutrients & calories. Ex. Paneer paratha, cheese-potato-tofu sandwich, soyabean cutlet, chicken roll, fish fingers (homemade), egg rice, fruit & nut milkshake/lassi, cow/buffalo milk with skim milk powder, fruit juice, sugarcane juice, thick creamy soup, thicker atta-maida rotis with ghee, rice with ghee.
2. Add home made cereal malt/premix to milk with sugar instead of protein powder.