Instruct: Classify an Amazon review into positive or negative sentiment.
Query: Not much energy

I took these for a week . The first day I first got the chills then became really warm, that happened the first 2 days. In the week I took it I didn't have any extra energy and my heart certainly didn't feel strained and wasn't beating any faster like some people said happened to them. My appetite wasn't suppressed any. I didn't get much from these so I stopped taking them.