Instruct: Classify Amazon reviews into positive or negative sentiment
Query: double it

Not sure how effective this really is, but seems like if you want to have that "nauseous" feeling some other reviewers talked about, then use 2. I had no problem with it falling off - even after exercise and showering. It probably works on a psychological level if you believe it will. It's worth a try to find out for yourself since it's sold at a much cheaper rate on Amazon...I probably won't reorder them, but will use them until they run out...2 at a time!