Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Works as advertised

Taking one pill on an empty stomach should have an effect, if so try taking the full two pill dose next time, if not then I suppose it won't work for your physiology. If it does work for you as it does for me, try experimenting with combing it with other nootropics such as Lion's Mane, l-theanine, etc... I suspect I'll continue to use this in some form.