My hallucinogen history: I have taken LSD, 2CP, 2CE, 2CT7, 5-MEO-DMT, Mushrooms, HBWR seeds, DXM, 5-MEO-AMT, DIPT, 4-ho-DIPT, and DPT.
The only ones of these drugs that have given me stomach discomfort was my first experience with HBWR, and my 4 experiments with 5-meo-amt.
I had heard that the yopo seeds are very painful to snort (I imagine that it's pure hell, just like snorting the 2C compounds).
I had the seeds lying around for a month, because I had heard of the body discomfort that they can cause. 2 days ago, I got the desire for a journey, but I didn't feel like taking the enormous journey that salvia provides.
I slowly heated 2 yopo seeds until they popped, and then I de-shelled them. I crushed them up and put them into my favorite glass bong. I took all the smoke in one big hit, and it didn’t taste too bad. Kinda nutty. I awaited the effects, but none came. 10 minutes later, I tried again with 3 larger seeds. I made sure to hold the smoke in for 20 seconds or so, then I exhaled, and went into my bedroom, so I could lay down and relax. About 2 minutes later, my stomach started churning. After another minute, the churning sensation had developed into full-fledged nausea. It felt even worse than the 5-meo-amt nausea.
I was very glad that I was already lying down, because moving my body caused the nausea to increase. Upon closing my eyes, I saw faint patterns, sort of like a colorful chain-link fence. Mostly, however, I was focused on the horrible stomach pain.
About 15 minutes later the pain faded, and I decided to never ingest those evil seeds again.