CytoGainer (Vanilla Shake) is an excellent product for fast weight gain. It has more protein per shake than most products, but has a lot of carbs too. I felt results in 2-3 weeks and started to gain weight after 3 weeks. I drank one Vanilla milkshake every night before bed, which helped my body process all the protein. I think it recommends 3 shakes a day but I personally didn't need that much. I highly recommend CytoGainer if, and only if, you do cardio with your routine, if you don't you'll probably gain fat too. It has a lot of carbs, but they seem to easily burn off. My strength went through the roof too. Great stuff for people who are just starting out or if you've plateaud your weight or strength. Also if your one of those who has a hard time gaining weight. The Vanilla tastes better than all the vanillas I've tasted too!