Sounds like Datura, It doesnt really belong in this forum, BUT, heres what I know.
It's very difficult to measure out a safe doseage.
I went to a party (when I was much younger & a whole lot stuider) & Datura tea was being passed around, I took a couple of sips & really dont remeber much.
I was very lucky in having two very close friends 'tripsitting' (beleive me you need it!).
6 of my other friends were not so lucky & ended up in ICU for a few days, one guy was in there a week & It really fucked with his personality.
So that was just one party, I know people who have gotten naked in the snow & ended up with frostbite, getting into police cars thinking they were god knows what, etc.
It effects your vision for a few days , maybe in larger dosages permanatly, I dont know.
My advice from first hand experience, dont take it!
If you absolutely must then have a couple of close, SOBER friends with you the whole time. It's hardly worth it , apart from maybe eding up in a coma , you wont remember much.