No problem, actually I don't know. My son is in his twenties this year. He has a cold all the year round, and he usually gets over it in ten days to half a month. He is also losing weight, and said that protein powder can increase immunity. He always drinks a cup of protein powder after every exercise, and his cold is really gone. But you don't have to worry, it will be better to drink it within an hour, and you won't gain weight. My son has lost weight, and drinking protein powder only increases immunity.