I'd never taken 25i before that time. I might not be able to tolerate it at all in moderate to large doses.
I've been taking Wellbutrin XL 300mg for a while, including today, and earlier I tried a dose of 10mg 2C-B. I was in a good mindset before dosing, with a low heart rate, but right after dosing I started to feel anxious and my heart rate jumped to 100, so I took .5mg Xanax. Overall it was a slightly dysphoric experience. The psychedelic effects expected from a low dose were mostly there, but the physical effects were more than I would have liked and much more than I'd experienced on a higher dose before Wellbutrin. Sore neck (vasoconstriction?), tense muscles, and a bit of body load. I've definitely felt the feeling in my neck before when combining psychs and Wellbutrin. Blood pressure normal (125/79) and heart rate 105 a few minutes after taking a walk, 90 lying on the couch watching TV. Didn't feel any real anxiety during the trip, but I did take the Xanax beforehand. My mood actually got worse as I was coming up, but I'm not sure why & don't think it could be related Wellbutrin.
I think I was right to stick with the low dose. I might have had a panic attack at 20mg. I'm not sure if I'll repeat this experiment for as long as I'm on Wellbutrin - maybe in a different setting. Compared to my positive experiences with shrooms and Wellbutrin, the psychedelic effects were not enough to make up for the physical side effects (but might have been if the drug had elevated my mood).
I think Wellbutrin is likely to increase physical side effects on psychedelics, but since some report not having these problems, I may be more susceptible to them. That, combined with increased anxiety while on Wellbutrin, makes me think I should avoid psychedelics for now.
EDIT: What would the effect of skipping a Wellbutrin dose or two be? I've stopped for days at a time before, back when I was on 150mg XL, and the withdrawal is minimal. Half-life data:
Wellbutrin itself: 12–30 hours, each of its metabolites:15–25, 23–43 and 24–50 hours. Clearance: 4–12 days. Could skipping Wellbutrin on Friday and Saturday morning be enough to make Saturday night a little safer for psychedelics?