Gainers are of two types :
1. Lean mass Gainer
Which contains 40-50% of protein blends along with a carbohydrate matrix. This helps to build lean muscle volume
2. Regular Mass Gainers
Which contains 10-25% of protein with a blend of carbohydrates, fat, and multivitamins. This is mostly used for those who are underweight. This helps to put on body weight faster for hard gainers.