As a healthy 21 year old, with no preexisting health conditions, on wellbutrin, (bupropion) is the preworkout C4 safe to use?

Wake UP, Ralph! It's a complete waste of money. Nothing in it you don't already make endogenously or can't get from regular MVIs (multivitamin). Consume stuff your body already makes, all that happens is that you need to make less of it. Excess amino acids etc are burned as fuel and the wastes excreted. So you'll stand there with your fly open & literally watch your money go down the toilet. Be a skeptic, not a sucker, Ralph.