I bought this on recommendation from someone who use to sell health supplements and I mentioned I was looking for Essential Amino Acids and he highly recommended Advanced Amino. I am glad I bought it, although I still find it a push to do my regular exercise routine at the gym, I think it has made a difference. I seem to be pushing through my exercise better. I should note I am in medical menopause and I take whatever I can, after some research, to help me deal with moods, lost energy etc. I notice my brain fog is not quite as bad as it was pre the aminos. The guy who recommended this to me looked fantastic for his age so that made the decision to try it a little easier.