Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Be very, very careful!!

Be very, very careful when you use this product! When I first used the product I read the product info on the bottle. The product information said use no more than one scoop. I always use caution so I took 1/2 scoop. Within 30 minutes I was shaking like a leaf. This product didn't help me get a pump. I couldn't even lift the weights. I didn't get a wink of sleep that night. It took 36 hours to feel normal again. O.K. I'm not 20 anymore. Maybe if I was young I could take it. But, for me, this product was "NO-help".