Withdrawal: The Science
Withdrawal is the body and brain readjusting after nicotine is removed. This section covers each major symptom: what it is, why it happens, typical timing and duration, what research documents, what varies between people, and what may help.
The core evidence
The time-course is documented by the landmark Hughes review — see R-007:
- Most physical symptoms peak in the first week and substantially resolve within 2–4 weeks.
- Craving is the exception — it declines slowly and can persist for months in waves.
- Symptoms vary widely between individuals in both intensity and duration.
Symptom overview
| Symptom | Typical onset | Typical duration | Page |
|---|---|---|---|
| Craving | Immediate | Weeks–months, in waves | cravings |
| Irritability | Day 1–3 | Peaks week 1, resolves ~2–4 weeks | irritability |
| Anxiety | Day 1–3 | Usually 2–4 weeks | anxiety |
| Low mood | Day 1–3 | Usually 2–4 weeks | low-mood |
| Sleep problems | Day 1–7 | Usually 2–4 weeks | sleep |
| Concentration problems | Day 1–7 | Usually 2–4 weeks | concentration |
| Restlessness | Day 1–7 | Usually 2–4 weeks | restlessness |
| Increased appetite / weight change | Week 1+ | Months for weight | appetite-weight |
| Cough | Week 1+ | Weeks–months (may transiently worsen) | cough |
| Headache | Day 1–7 | Usually 1–3 weeks | headache |
| Fatigue | Day 1–7 | Usually 2–4 weeks | fatigue |
| Constipation | Week 1+ | Usually 2–4 weeks | constipation |
Timings are typical patterns from the research literature and clinical descriptions, not guarantees — individual variation is the rule.
Important boundary
Withdrawal symptoms are usually mild-to-moderate and self-limiting. Some symptoms — chest pain, blood-streaked phlegm, persistent fever, severe or worsening breathlessness — are not typical withdrawal and warrant medical evaluation. The practical, plain-language version lives on the main site.