I am no expert but have heard lots of talk about SN. What I have heard is that 15-20mg should suffice, but 20mg is obviously more likely to cause you to vomit despite antiemetics. Personally I'm using night night, but have asked someone and for someone of my weight/size, 20mg would be better. I can't imagine the need to go beyond that. I think it would certainly cause you to vomit. Imo, you're best off with MAX 20mg and prepare a second dose in case of vomiting. Hope that helps.