My stomach is very sensitive to MDMA, got much worse after first time, I narrowed it down last night and what's causing it is a big shot of adrenaline that I think my stomach triggers in response to the MDMA's initial come-up, I get thrown into a panic attack and will projectile vomit unless I already have taken some kind of OTC or Rx proton pump inhibitor (omeprazole, prevacid, etc.) the day before AND I also gotta take a tablespoon of Baking Soda (one of the best antacids you can take) in a shot glass with water to make sure my stomach is basic before I get the Achalaysia (LES or muscle that lets your stomach contents flow into your intestines to get absorbed) which freezes this muscle and prevents the MDMA from getting to where it needs to go to get fully absorbed. I've got a script of calcium channel blockers that should also prevent the Achalaysia in the future which is the worst problem aside from stomach acid because this will keep you nauseous and force your stomach to absorb a harsh salt that your body is forcing to reject. Sorry for reposting but if anyone else is like me this is what causes 100% of my nausea from MDMA and many other drugs and some random substances/herbs.