Though this stage only lasts about 1 to 3 days, it is the most painful. People will begin to experience withdrawal effects about 6 to 8 hours after they last used the drug if it was a regular-release medication. If, however, the drug was an extended-release type, they may not begin to experience withdrawal effects until 10 or 12 hours after their last dose. The symptoms experienced here normally include pain in the joints, bones, and muscles, flu-like symptoms, and anxiety.