I have been using Z-Mass PM for about a month now. I actually sleep great on it! I havent seen big results, although I have noticed some. It may also be due to the fact that I am a female. I have been trying to find a supplement in pill or liquid form to increase my muscle mass/tone. That's why I thought I would try Z-Mass. I am so tired of taking protein shakes ALL the time, plus my schedule and time doesnt permit the making and drinking of the big thick shakes as much as it requires. So if any of you have any info or advice to help a woman increase muscle mass and tone with certain supplements (other than the shakes), please do let me know! Thanks.