^^Too true, 2c-i seemed to ignite my body, lots of twitches, feelings of cramping, involuntay movements, jaw clenching, nystagmus, sweating, involunatry swallowing- most stimulants/ phens I think induce a 'strong' or 'heavy' body load.
Marijunana is very much a body load type of drug- half the high is in how your body feels.
I consider LSD 'clean' when it has little body load which is most of the time. This is what has lead me to beleve LSD is non-toxic (besides all I've read)- it barely sets of any physical responses in the body, whereas most drugs inadvertantly do.
Body load can feel good or bad- on 2c-i the felings were based on euphoria and being ultra-energised which felt great

. But I find with speed, where I'll exhibit similar symptons, this is more based on over-stimulation and nervous/ fight or flight/ adrenalin responses which directly affect the physical body and make me feel awful.
I guess the cause of 'body load' would be side effects or direct effects of a drug- most amphets weill cause a large body load due to the relase of stress hormones. DMT and salvia cause very physical responses, but it is hard to draw the line between pyschedelic hoo ha and genuine physical senstaion.
Its hard to actually think of a drug that causes no body load . . .