as jackie said, there are a lot of variables at play. for me day 3 was always the hardest, the one i'd almost inevtiably relapse on. i was addicted to heroin so can comment on that- day 1 would be crappy but i'd be mentally prepared and not lost my motivation yet, the worst symptoms wouldn't have kicked in yet. day 2 would get worse, by day 3 the symptoms that caused me the most pain, RLS and 'stomach issues,' would be peaking and they were just relentless. plus i'd done 2 days without so deserved a treat, right? if i made it past day 3, and i can count the times on one hand, despite having got to day 3 probably at least 30 times, day 4 things would be slightly better. day 5 slightly better again, stomach would be calming, still horrendous night sweats, rls, lethargy, depression. at this point i'd be physically able to do things like pop to the shops. the lethargy would linger longest and i'd still get intermittent night sweats over the next few weeks.