Champix

What is Champix?

Champix is a prescription medication that helps to manage cravings and other withdrawal symptoms when you stop smoking.

It’s a tablet you take every day, and it’s given in 12 week courses. When you successfully stop smoking while taking it, a clinician may give you another 12 week course after the first one, just to make sure the job is completely done.

Before you start taking it, you’ll decide on a date where you stop smoking. This is usually between day 8 and 14 of treatment. You’ll start on a lower dose for the first few days and gradually build up to a maintenance dose by day 15.

Champix was temporarily withdrawn from the market in 2021, but it made a comeback in July 2025 after Pfizer, its manufacturer, updated the formulation to make sure it meets safety standards.

How does Champix work?

Champix works by blocking the receptors in the brain that are affected by nicotine. This means nicotine no longer produces the ‘feel good’ hormone response of dopamine.

With nicotine being blocked, the short term pleasurable effects from smoking which cause cravings are prevented. This makes it easier to avoid smoking until the cravings pass and you can consider yourself a non-smoker.

And if you do smoke while taking Champix, it doesn’t produce the same feeling in the brain, so it helps to make smoking less appealing.

How effective is Champix?

Clinical studies have shown that Champix is effective at helping people quit. People taking it were more likely to have abstained from smoking after a year of starting it, compared with a placebo. It’s also been found to be more effective than nicotine patches at promoting abstinence during treatment, and at one year following treatment.^[1]

Champix can be particularly helpful if you’ve tried other ways of quitting smoking before but these have been unsuccessful. By managing the cravings and reducing the withdrawal symptoms — the things that most people find difficult when quitting smoking — it increases your chances of success.^[2] You’ll still need some degree of willpower, but it can give you that extra bit of breathing space to get through the most difficult moments.

Some research also suggests that combining counseling with stop smoking treatments can help to further increase your chances of successfully quitting. ^[3]

How to use Champix

Champix instructions

Read the leaflet that comes with the medication before you take Champix. This should tell you everything you need to know about taking it, but if you’re unsure of anything, ask our clinician. Before you start Champix, you’ll need to plan your quit date where you actually stop smoking. This is usually during the second week of taking it. You’ll begin Champix on a low dose and increase this over the first couple of weeks.

How to take Champix

In your Champix starter pack you’ll get white tablets and light blue tablets. The white tablets carry 0.5mg of the active ingredient, varenicline, and the light blue tablets carry 1mg.

• On days 1-3 of treatment, take one white tablet once a day, at the same time each day.
• On days 4-7 of treatment, take one white tablet twice a day, one in the morning and one in the evening, at the same times each day.
• From day 8 onwards, take one light blue tablet twice a day, one in the morning and one in the evening, at the same times each day.
• You can take your tablet with or without food.
• Swallow your tablet whole with a glass of water.

After you’ve completed the starter pack, you’ll move on to the maintenance pack that only contains 1mg light blue tablets. A course of Champix lasts for 12 weeks. If you manage to give up smoking successfully during this time, you might be prescribed another 12 week course to increase your chances of staying quit. If you aren’t successful at quitting when using Champix, it can sometimes help to take a break from the treatment and try again once you’ve been able to address the other factors that caused you to smoke.

Do some people need a lower dose of Champix?

The maintenance pack is available in a 0.5mg dose in addition to the 1mg dose. These lower dose packs contain all white tablets, which you take in the same way as the higher dose pack: one tablet, twice a day. You might be recommended the lower dose of Champix if you’re older, or you’ve had a sensitive reaction or side effects when using the higher dose. Your clinician will always advise you on the best dose to use.

What if I miss a dose when taking Champix?

Let us know if you forget to take your tablet. If your next scheduled dose is more than four hours away, you can take the missed tablet as soon as you remember and take your next one at the usual time, and continue. If you forget to take Champix and your next dose is due in less than four hours, skip the dose you missed and carry on taking it as normal.

When can I stop taking Champix?

During your time taking Champix, you’ll have continuous monitoring with a clinician to make sure it’s working for you. If you successfully quit, your clinician will advise you on the best time to stop taking it (to minimize the risk that you’ll get cravings and want to start smoking again). You should continue taking Champix for as long as recommended by your clinician. But tell your clinician right away if you get any side effects or think that you need to stop taking Champix immediately.