I know this is an old thread but this must be said. Is 15mg dangerous? Well, when the doctors were first setting the prescription dosage they took their testing as high as 90mg. So, no, in that way it isn't dangerous. The problem comes since Ambien is a hypnotic you can find yourself doing things while you are asleep such as driving a car without remembering a thing about it. Or going shooting and not have a clue what you're shooting at. So, will it hurt you? Not likely but it could kill someone else and you'd wake up in the morning with no memory of killing them so no way to defend yourself. You could spend the rest of your life in prison just because you wanted a little high you were told was safe! I took a prescribed dose of 10mg and was on my motorcycle in my pj's and robe ready to leave the garage. Good thing my wife stopped me, and I remembered nothing but a dream of me on my bike! With Ambien you should always start at 5mg (with someone else around) and work up from there, if needed. Ambien can start very fast, as little as ten minutes so be careful with it. If you are looking for a high there are safer ways to get it.