Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Does not seem to work

I have been taking L-Citrulline for several months. I have been using a capsule product by a well know vendor and always can feel the effects within an hour.Under certain circumstances as a male I take two or more and this has always been highly effective. This hard pill version gives no effect, I don't even know if I have taken it.Very, very, disappointed and I am a Source Naturals fan. I will not re-order unless I find that I got a rare mistake that was either too old or not stored properly.