STOP SMOKING TREATMENT
Champix (varenicline)
A prescription tablet to help you stop smoking. Varenicline works on the brain’s nicotine receptors to reduce cravings and ease withdrawal, while making smoking less rewarding. It’s taken as a 12-week course, started shortly before your quit date. A prescriber confirms it’s right for you first.
At a glance
Nicotine-free
Contains no nicotine and isn’t addictive.
12-week course
Started 1–2 weeks before your quit date.
Twice daily
A tablet taken with water, morning and evening.
Prescriber-led
Supplied only after a clinical assessment.
What is Champix?
Champix is the brand name for varenicline, a prescription-only medicine that helps adults stop smoking. It contains varenicline tartrate, is not a nicotine product, and is taken as tablets over a 12-week course. Because it’s a POM, it’s supplied only after a prescriber has reviewed your suitability.
Varenicline is one of the most effective stop-smoking medicines, and works best alongside genuine motivation to quit and the right support — something your prescriber can talk through with you.
How it works
Nicotine addiction is driven by nicotine binding to certain receptors in the brain (the α4β2 nicotinic receptors), which triggers a release of dopamine and the sense of reward that keeps smoking going. Varenicline is a partial agonist at these receptors: it partly stimulates them — enough to ease cravings and withdrawal — while at the same time blocking nicotine from binding, so a cigarette becomes far less rewarding. That dual action is what makes it effective.
How to take it
Start Champix 1 to 2 weeks before the date you plan to stop smoking. Swallow the tablets whole with water, with or without food. The dose steps up gradually over the first week:
| When | Dose |
|---|---|
| Days 1–3 | 0.5 mg once a day |
| Days 4–7 | 0.5 mg twice a day (morning and evening) |
| Day 8 to end of course | 1 mg twice a day (morning and evening) |
The usual course is 12 weeks. People who have stopped smoking by the end may be offered a further 12-week course to help prevent relapse. If you miss a dose, skip it and carry on as normal — don’t take a double dose. [REVIEW: confirm dosing, course length and missed-dose advice against the current SmPC.]
Is it right for you?
Who it may suit
- Adults who want to stop smoking
- Ready to set a quit date
- Motivated to quit with support
Tell your prescriber if you
- Have or have had depression or other mental-health conditions
- Have kidney problems
- Have heart or circulation problems
- Have epilepsy or a history of seizures
- Are pregnant, breastfeeding or planning pregnancy
Important: tell your prescriber about all medicines you take. Varenicline may interact with other treatments (for example certain medicines for mood or anxiety, blood thinners, insulin, theophylline for asthma) and shouldn’t generally be combined with nicotine-replacement products without advice. This isn’t a full list — your prescriber reviews your history.
Side effects
As with any medicine, some people get side effects. The most commonly reported is nausea, which is usually mild to moderate and often eases over time. Other common effects include headache, difficulty sleeping, vivid or unusual dreams, dry mouth and constipation.
Mental-health changes: some people have reported changes in mood, agitation, depression or thoughts of self-harm while taking varenicline. If you or those around you notice changes like this, stop and seek medical advice promptly. Seek urgent help for any thoughts of harming yourself, or for signs of a serious allergic reaction (swelling of the face, lips or throat, or difficulty breathing). [REVIEW: confirm neuropsychiatric wording against the current SmPC.]
Summary
| Active ingredient | Varenicline (as varenicline tartrate) |
| Type | Prescription tablet to stop smoking |
| How it works | Partial agonist at α4β2 nicotine receptors |
| Course | 12 weeks (further 12 weeks may be offered) |
| Contains nicotine? | No |
Frequently asked questions
Yes — Champix is the brand name and varenicline is the active ingredient. Generic varenicline contains the same active ingredient and works in the same way.
Start 1–2 weeks before your planned quit date, so the medicine has time to build up and begin reducing cravings before you stop.
The standard course is 12 weeks. If you’ve stopped smoking by then, your prescriber may offer a further 12 weeks to help prevent relapse.
It’s designed so smoking becomes less rewarding, and continuing to smoke can increase side effects. The aim is to stop on your quit date and use the medicine to support that.
No. Varenicline is a prescription-only medicine. You’d complete a short online consultation, and a prescriber checks whether it’s suitable before it can be supplied.
Some people find they’re more sensitive to alcohol on varenicline. It’s sensible to be cautious and discuss your alcohol use with your prescriber.
Clinical review
Medically reviewed by
Muhammad Mahmood
Superintendent Pharmacist · GPhC 2221957
Page status
Last updated: 14/08/26
Checked against the Champix / varenicline SmPC
References & sources
- Champix (varenicline) Summary of Product Characteristics & Patient Information Leaflet — emc (medicines.org.uk/emc).
- NICE / NHS guidance on stop-smoking treatments.
- MHRA Yellow Card scheme — yellowcard.mhra.gov.uk
For UK audiences; general information only, not a substitute for your prescriber’s advice or the Patient Information Leaflet. Always read the leaflet supplied with your medicine.
