What is Champix?
Champix (varenicline) is a prescription-only medicine approved by the European Medicines Agency (EMA) to support adults in stopping smoking. It is the most clinically effective pharmacological treatment for smoking cessation currently available in the EU, based on comparative clinical trial data.
Champix is not a nicotine product — it works through a different mechanism from nicotine replacement therapy (NRT). It acts directly on the nicotinic receptors in the brain that are involved in nicotine addiction, both relieving withdrawal symptoms and reducing the satisfaction associated with smoking.
How does Champix work?
Varenicline is a partial agonist at alpha-4 beta-2 nicotinic acetylcholine receptors — the receptors most strongly associated with nicotine dependence and the rewarding effects of smoking.
Its dual mechanism of action is what makes it distinctive:
- Partial agonist activity: Varenicline stimulates nicotinic receptors at a lower level than nicotine, reducing cravings and withdrawal symptoms without delivering a full nicotine “hit”
- Receptor blockade: By occupying the receptor, varenicline partially blocks nicotine from binding if the patient smokes during treatment, reducing the rewarding effect of cigarettes and thereby weakening the positive reinforcement of smoking
This combined action — reducing withdrawal discomfort while also diminishing the reward from smoking — makes varenicline particularly effective at supporting sustained abstinence.
Who is Champix for?
Champix is indicated for adult smokers who are motivated to stop smoking. It is suitable for adults who have tried and failed with NRT, who prefer a non-nicotine pharmacological approach, or who smoke heavily and anticipate significant withdrawal challenges.
Important considerations before starting Champix:
- Patients with a history of psychiatric illness (including depression, bipolar disorder, schizophrenia) should discuss the risks and benefits with their doctor before starting treatment
- Champix should be used with caution in patients with severe renal impairment
- Champix is not recommended for use during pregnancy
- Adolescents under 18 years should not use Champix
The most effective smoking cessation approach combines pharmacological treatment with structured behavioural support, such as counselling or a stop-smoking programme.
Dosage
Champix is taken orally as a tablet, with or after food, and a full glass of water. The dose is escalated gradually to reduce the risk of nausea.
| Phase | Dose | Duration |
|---|---|---|
| Days 1–3 | 0.5 mg once daily | 3 days |
| Days 4–7 | 0.5 mg twice daily | 4 days |
| Weeks 2–12 | 1 mg twice daily | 11 weeks |
| Optional extension | 1 mg twice daily | Up to 12 additional weeks |
Patients should set a quit date, ideally 1–2 weeks after starting Champix, to allow blood levels to build up. Some patients may prefer to start Champix and then choose a flexible quit date within the first month of treatment.
Side effects
Very common side effects (affecting more than 1 in 10 people)
- Nausea: The most frequently reported side effect; typically mild to moderate and often reduces over time. Taking with food helps.
- Vivid, unusual, or abnormal dreams
- Headache
- Insomnia
Common side effects
- Increased appetite
- Fatigue
- Dry mouth
- Constipation or diarrhoea
- Dizziness
Important risks to monitor
- Neuropsychiatric effects: Changes in mood, behaviour, or thinking, including depression, agitation, hostility, suicidal ideation. These have been reported in patients taking Champix; the contribution of nicotine withdrawal versus the medicine is debated. Patients with existing psychiatric conditions should be closely monitored.
- Cardiovascular events: Some data has suggested a possible increase in cardiovascular events in patients with established cardiovascular disease. This should be discussed with the prescribing doctor.
- Seizures: Reported rarely; Champix should be used with caution in patients with a history of seizure disorders.
Champix vs alternatives
| Treatment | Active Ingredient | Mechanism | Prescription Required | Relative Efficacy |
|---|---|---|---|---|
| Champix | Varenicline | Nicotinic partial agonist | Yes | Highest (pharmacological) |
| Zyban | Bupropion | Dopamine/noradrenaline reuptake inhibitor | Yes | Moderate |
| NRT (patches/gum/lozenges) | Nicotine | Nicotine replacement | Generally No | Moderate |
Clinical data consistently shows varenicline to have the highest quit rates among pharmacological interventions. However, individual patient factors — including tolerability, history, and preference — should guide treatment selection.
How to access Champix online in Europe
Champix is a prescription-only medicine in all EU member states. It cannot be legally dispensed without a valid prescription from a qualified medical professional.
Prescrivia operates as a technology intermediary, connecting patients with independent EU-registered doctors for online health assessments. We do not prescribe medicines, employ doctors, or sell medicines directly.
- Complete a health assessment: Provide information about your smoking history, motivation to quit, medical history, and current medications.
- Doctor review: An independent EU-registered doctor reviews your assessment. If varenicline is clinically appropriate, they may issue a prescription.
- Prescription and fulfilment: If a prescription is issued, it is sent to a licensed EU pharmacy partner for dispensing and direct delivery.
Important: Prescrivia does not guarantee that a prescription will be issued. All prescribing decisions are made independently by qualified medical professionals.
Important safety information
Tell your doctor if you:
- Have a history of depression, bipolar disorder, or other psychiatric conditions
- Have or have had kidney disease
- Experience any change in mood, behaviour, or thinking while taking Champix
Driving: Some patients experience dizziness or somnolence with Champix. Do not drive until you know how the medicine affects you.
Alcohol: Patients have reported increased alcohol intoxication or unusual behaviour while drinking alcohol during Champix treatment. Take care with alcohol consumption.
Sources
Medical information on this page is based on the following sources:
- European Medicines Agency (EMA). Champix (varenicline) — Summary of Product Characteristics. ema.europa.eu
- European Medicines Agency (EMA). Assessment report: Champix. EMEA/H/C/000699.
- World Health Organization (WHO). Tobacco — Fact sheet. who.int
This content is reviewed periodically to reflect updated clinical guidance. It is provided for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for advice relevant to your individual health circumstances.
Frequently asked questions
- What is Champix used for?
- Champix (varenicline) is a prescription medicine used to help adults stop smoking. It is a partial nicotinic acetylcholine receptor agonist — it both reduces cravings and withdrawal symptoms and decreases the rewarding effects of cigarettes if the patient continues to smoke during treatment.
- How effective is Champix compared to other stop-smoking treatments?
- Clinical trials reviewed by the EMA indicate that varenicline approximately doubles the likelihood of successful quitting compared to unassisted quit attempts, and shows superior quit rates compared to bupropion (Zyban) and nicotine replacement therapy (NRT) in head-to-head studies. Combination with behavioural support further improves outcomes.
- What are the most common side effects of Champix?
- The most commonly reported side effect is nausea, affecting up to one third of patients. This is usually mild to moderate and often improves after the first few weeks. Taking Champix with food and a full glass of water can help reduce nausea. Vivid or unusual dreams are also commonly reported.
- Can Champix cause mood changes or depression?
- Mood changes, including depression, agitation, and changes in behaviour, have been reported in some patients taking varenicline. It is important to note that nicotine withdrawal itself can also cause mood changes, making it difficult to attribute causation. Patients with a history of psychiatric illness should discuss this with their doctor before starting Champix. Any concerning mood changes should be reported to a doctor promptly.
- How long is the Champix course?
- The standard course of Champix is 12 weeks. Patients who successfully quit smoking during this period may benefit from a further 12 weeks of treatment to reduce the risk of relapse. The total recommended treatment duration is therefore up to 24 weeks for sustained benefit.
Behandlinger
Prescrivia er kun en formidlingsplattform. Vi leverer ikke medisinske tjenester, forskriver ikke behandlinger og utleverer ikke legemidler. Alle medisinske beslutninger tas av uavhengige EU-registrerte leger. Alle legemidler utleveres av lisensierte EU-apotek. Denne plattformen legger til rette for kontakt mellom pasienter og helsepersonell.