It is different for everyone, and depends on amount
of use, over what period of time, what substance and your own body chemistry. If you taper (i.e. start slowly reducing your usual dosage) you can limit (but not totally eliminate withdrawal). If you take 3 a day, one every 8 hrs, try taking .75 every 8 hrs for 3 days, then .5 every 8 hrs. for 3 days, and so on until the end. If you have minor withdrawal symptoms, clonidine can help (it is a blood pressure med.