I am 73. I was losing muscle mass...weak and tired. Read the information about Advanced Amino and many of the testimonials. Convinced me enough to give them a try. Glad I did. So far, only good results. More energy, less sore and more lean muscle. In such a short time I'd say those are great results. Went back and read the protein utilization is 99%. Always, read about having to take in huge amounts of protein daily from outside. Never realized with the proper balance of amino acids the body can make plenty of the different kinds of proteins it needs. I'm all for supporting the body doing what it needs to do.