Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Puts me to sleep but not sure about other benefits

This is my first experience using ZMA. These NOW brand ZMA capsules definitely produce a biological effect for me. I'm about halfway through the 180 caps. From my experience so far, two of the capsules put me to sleep like a baby. Three of the capsules put me to sleep but cause me to wake up midway through the night. As for the claimed muscle growth effects, it's impossible to tell at this point if I've made any mass gains. But, improved sleep has to help improve muscle recovery. From my research, the scientific literature seems to indicate that ZMA does not provide substantial muscle gain. I'm not sure if I'll continue to take these tablets after my supply runs out.