the last couple of times my running mate and i have done our normal doses, we've both fallen out to differing degrees. the first time, i weighed out our doses, i shot first, and was fine. stronger than usual, but nothing i couldn't handle. he, on the other hand, went full under: lips blue, fucked up breathing, unresponsive, all from the same dose and tolerance level. i had to hit him with some narcan, which luckily i had just gotten at the exchange. i suspected the reason was that he had used my same tin and cotton, perhaps adding a bit more to his shot, or maybe had taken a benzo or some other medication i didn't know about, potentiating his high.
the second time, same situation. same dope, same weight, i went first. what happened next i had to hear from my friend, who told me that i had gone under, started drooling, remained unresponsive for 5 minutes or so, and finally was brought back around by him smacking and shaking me. now this time i know i had no other medications in my body, though it had been some time since i'd eaten.
now THIRD TIME, by far the strangest. it was NYE and i had to work (catering) and had been rolling meth bowls on the job as i did so. i ate plenty, did not drink alcohol, and took a 2mg klonopin at some point. now by this time i was exhausted but drove over to my buddies place anyways at about 4am to fix. i decided that i would lower my normal dose from .15 down to .1 due to the benzo in my system. despite my plead for him to split his dose, my buddy stuck with his usual .2. so i hit myself about 6am, get rid of my rig and clean myself up, start to nod, and the next thing i know it's 3 HOURS later, my buddy is next to me on the nod with the rig still in his arm, almost all of his second shot in his veins. i take it from his arm, smack him awake, try to piece together what was going on, and the next thing i know i began to sweat UNCONTROLLABLY. like, nodding in and out, zombie leaning, shirt off, and literally sweat dripping off my face. i laid down and was fucked up for hours. my buddy on the other hand, was totally fine.
after these experiences i've definitely started underdosing my first time around, and then bumped up as needed. those 3 experiences were just too weird for me, and i still can't explain them, except to say that they sufficiently scared the shit out of me. i'd never seen an OD before, nor had i ever had such a shitty reaction to such a small amount of dope (.1). lately my reactions have just been all over the map, so i figure better safe than sorry.