Honestly, nothing has ever worked for me to help with hbws nausea. It's just part of the experience, kind of a trade off if you will. Not every time is bad, but when it's bad it's like 5 hours of nausea/gi issues, and your left with a few hours of actual good tripping unless you doses high.
Take the ticket - take the ride! Most of the time perceived vasoconstriction, is just underlying anxiety - unless you're puking and got diarrhea.