Its completely safe unless your diet has too much protein in it already which could be hard on your kidneys. Whey is from milk. Milk is 20% whey and 80% casein. Getting whey protein in a shake makes it more available. It saves you from having to have a meal ready after every frickin workout which is time consuming and unnecessary. Whey is used primarily for post workout protein intake since it is a fast digesting protein with a really good amino profile. I recommend, if you have the discipline, depending on what your goals are, taking whey within no longer than an hour after working out with a 3:1 ratio of simple carbs and protein. The carbs help in the digestion of the protein including allowing you to recover better. Also, when it comes to protein intake try to get at 3 solid meals a day. All in all 5 to 7 small meals is the best way for the best gains. A good rule of thumb I go by is protein every 2 1/2 to 3 hours. Another thing is people like to take a drink before they workout. There are added benefits, but in my opinion it is really unnecessary as the most important is post workout. Anyways, this is what I can think of off the top of my head. Im sure I could tell you more, but I am very tired and figured I'd be nice enough to help out. Hope all this can assist you a good way. Any questions feel free to ask.