I aint gonna lie, a year ago I tried that trash, got a really good high and went on a 4 week tweak binge and believe me the chemicals and lack of sleep will turn you into a monster. Man if your bro is back on that sh*t there isnt much you can do for him except encourage him to stay off of it, other than that its gonna have to be his choice to quit. See the thing with tweak is that you smoke it or snort it and feel good, talkative and somewhat more concentrated than normal. I've drawn landscapes with great detail on that sh*t and I suck at drawing, but when you come down it really sucks, you feel the opposite of how you felt before and this causes your body to want more to be energized again in a false manner, and overtime it becomes a very vicious cycle and it can be very difficult to drop the habit without a strong mind. and whats f*cked up is that some people use it and see that it helps when it comes to going to work. You work way better on it, but this also fuels the cycle and it sucks.
I quit that sh*t as soon as I saw that it quickly was making me feel more irrate, less confident, and my limbs and flesh began to feel cold, numb and uncomfortable, and my lips felt all crusty and nasty, and man that sh*t will f*ck your world up..And I've seen a few of my friends start that crap and they really ruin their normal routine in life and some have ruined it and ended up in jail, rehab, or shot...I HATE METH, and the smell I hate the worst