Withdrawal usually begins within days of stopping and fades over weeks
Symptoms, which can include shock-like electrical sensations, tend to start within days of stopping. Most clear within weeks; for a minority they last months, for some over a year.
What the study found
Venlafaxine withdrawal starts within days and usually lasts weeks
In 61 reports on stopping drugs in venlafaxine's class, symptoms began within days and cleared over weeks even with gradual tapering; a minority ran longer. The label lists 27 symptoms, including electric shocks, and severe, drawn-out cases. For some, says the Royal College, over a year.
The caveat · 23 of 61 are single case reports
Twenty-three of the 61 reports were single case reports, and no pooled figure exists for how many people get a prolonged course. The label's drawn-out cases come from voluntary reports with no denominator. NICE puts the usual course at one to two weeks, occasionally months.