I have to confess- this is my second time taking Centra Peak. After having taken the product for some time, I decided to try something different. THAT was a mistake!! After bouncing around and trying different supplements (and not seeing the results I did with Centra Peak)- I finally made my way back!! I know...I know. Thing is that I'm not a big fitness junky that is looking to build up massive biceps- no, I'm just a regular 52 year old man that has regular 52 year old man problems. Low energy, trouble sleeping, concentration issues. And within a couple of weeks after stopping Centra Peak- all of those issues returned. I went through a flurry of trying different supplements that promised to improve all of those issues, but all fell short. Shoot- some of them had me taking up to 6 pills/supplements per day. After a while, I finally realized that I had stopped the one supplement that actually helped me. Now, I'm no brain surgeon, but it doesn't take a genius to figure out what I needed to do. I have now been back with Centra Peak for roughly six months and can definitely tell a difference!! I can sleep again!! That's huge! My energy stores are up and continuing to improve. It's easier to concentrate now (getting more sleep absolutely helps with that). Heck, I've actually gotten enough energy back now that I'm seriously thinking of getting back into my workout routine!! Gentlemen, I can't speak for everyone, but what I can say is that I can't recommend Centra Peak highly enough. Do yourself a favor and give it a shot. I recommend you purchase the 4-pack or the 8-pack and try it out. It has a cumulative affect, it's not like you can take one bottle for a month and see the complete benefits. Yes, you'll see "some" benefit, but in my opinion- if you order the 4-pack (which is actually a 3-pack with a FREE month) that will give you sufficient time to see what Centra Peak has to offer!! Give it a try- you'll see what I mean.