it all depends on individual.
got a friend who felt nauseous n vomitted after inject epi. n felt really really awful (giddy) after delivery.
but for me, i only felt itchy under my skin once injected 'cause of my sensitive skin. so nurse reduced my dosage by half. no other symptoms. i even managed to sleep peacefully thru out the nite.
i only experienced mild contractions, i think once every 5-10 mins.
delivery was natural n ez. i still got energy to kpo around n take pics of my husband n baby,.... only took nap after i'm pushed to normal ward.
the epi injection not painful at all 'cause before that, they'll inject you a GA. but if you have phobia of needles (like me), then it'll b vvvvv scary. the doc will explain the procedure of the injection in detail, unless you dont want to know.
oh ya, i shiver like hell also fr before inject all the way till the liquid is in. after that, no more shivering. but start to feel itchy.
as for long term side effects, i did ask my doc about it. he said that if it's not properly injected (which usu wont happen 'cause the docs r very experienced), then will suffer backaches n stuff. if not, it shld b rather safe except those short term side effects.
actually many mothers suffer backaches not 'cause of epi, but due to not resting enough during confinement, carrying heavy stuff (e.g. baby as they r older) for too long,... of cos our hormones is part of culprit too. loosening our bones. actually giving birth is vvvv detrimental to our health. that's y need lots of rest after that.