I'm taking LSD for the first time ever this Sunday, have some concerns.

I'm sure the tab that I bought is real, my cousin gave it to me and he has great experience with psychedelics. He's already tried the tabs before and had a great experience so far. The thing is that he doesn't know how much ug is in each tab. He says it's somewhere below 200ug each, but he's not too sure. Should I split the tab to play it safe or just take the tab? He told me he gave one to this other girl who's like 5 foot flat and she reported back with a good trip, it lasted her 12 hours. So I've been thinking since she's been okay taking one tab then I should be okay as well? What do you guys think?