I been working out for the last month trying to pack on muscles, which is working I went from 150 to 154 now I weigh 164. I been taking protein powder gainer, but I actually seen their is creatine in it, which I know they say to drink lots of water with.

Does creatine dehydrate you?

Is it a creatine monohydrate or a different blend? If it is a monohydrate then yes it will dehydrate you. Regardless you can still just drink more water and you are hydrated. Exactly what brand is it?

Its Muscle-tech

Your probably fine. Your water intake will increase with your workout. And as with any supplement, extra water doesn't hurt. I wouldn't necessarily say it dehydrates you, but the supplement will be more effective with more water.

What do those supplements do exactly? Make you thinner or increase you muscle definition?

All it does it make your muscles retain more water, helping with the healing process and possibly able to lift more although I have not experienced that at all.

Personally, I think that unless you're preparing for a show and you need the extra energy you can get during a workout, plus the perceived size gain due to the muscles retaining more water, ditch the creatine.

If you get really sore, go for glutamine because you might be missing it in your diet/overtraining and it can really help with healing.

Creatine: A rough explanation

Creatine is a naturally found substance in your muscles (and small amounts of it are in red meat). As you work out, and the creatine stores in your muscles run out, you fatigue. By taking a creatine supplement, you have an elevated creatine level, thus you don't run out as quickly and can lift more, resulting in more muscle breakdown and more muscle building benefit. Most creatine supplements come with glutamine in it. If you lift 3 or more times a week and take a modern creatine supplement you will see more strength and musclemass gain than you would otherwise.

Glutamine helps with muscle recovery/repair. Although a routine lifter will already have a shorter recovery time.

I been lifting 5 to 6 days a week for about an hour or so.