For short-acting opioids like heroin, withdrawal symptoms typically begin 6-12 hours after the last dose, peak at 48-72 hours, and improve substantially by days 7-10. For longer-acting substances like methadone, onset is delayed to 24-36 hours, with peak symptoms occurring around days 4-6 and persisting longer.
Common withdrawal symptoms include:
Muscle aches and bone pain
Nausea, vomiting, and diarrhoea
Abdominal cramps
Anxiety and restlessness
Insomnia and sleep disturbance
Sweating and goosebumps
Increased heart rate and blood pressure
Post-acute withdrawal symptoms—including mood disturbances, cravings, and sleep problems—may persist for weeks or months, requiring ongoing support.