How does Champix work?

The active ingredient is varenicline which blocks the pleasurable effects of smoking and at the same time reduces cravings. It does this by attaching to and partially blocking nicotine receptors in the brain.

How long should I take Champix?

A course of Champix is 12 weeks including an initial build up period of 7 days. Smoking is stopped on a specific quit day during the first two weeks. People who have previously failed to stop when they took Champix for 12 weeks can try again using a longer course 24 weeks. Taking Champix for longer improves the chance of quitting permanently.

Why do I need a starter pack?

Champix is started at a low dose (0.5mg) and built-up over the first 7 days. The starter pack contains the necessary tablets and instructions for the initial two weeks.

Will Champix work if I smoke while I take it?

Smoking should be stopped completely after the initial 2 week build-up period. Most people who smoke and take Champix at the same time are likely to fail. However, people who have failed to stop with a 12 week course could try again with reduced smoking during the first 12 weeks and stopping completely whilst continuing treatment for a further 12 weeks.

Can pregnant women take Champix?

Caution should be applied when taking any medicine whilst pregnant or breastfeeding. Champix is not recommended during pregnancy or breastfeeding. Instead nicotine replacement products are preferred. Your midwife or doctor can usually advise and refer you to specialist 'support to stop smoking' services.

Can I use nicotine substitutes and Champix at the same time?

No. Champix blocks nicotine receptors. Nicotine substitutes such as gum, patches, or vaporisers will be ineffective and counterproductive.

Can everyone take Champix?

No. People taking some prescribed medicines and with pre-existing medical conditions should not take it. Checks are carried out during online consultations. People with a history of significant psychiatric conditions, particularly depression, should not take it. Consult your doctor if you are unsure. People taking some prescribed medicines including antidepressants should not take Champix.

Why is there a low dose 0.5mg Champix tablet and a standard dose 1mg tablet?

Some people find the standard Champix strength 1mg tablets too strong and do better with the lower strength 0.5mg tablets. After the initial build up, most people take a 1mg tablet twice daily for 12 weeks, which can be reduced to 0.5mg twice daily for those who experience troublesome side effects. See list of side effects in the patient information leaflet supplied with tablets.

What is nicotine withdrawal?

Nicotine triggers the release of pleasure chemicals, including dopamine in the brain. The brain quickly becomes habituated to the nicotine effect and when it is removed, there are symptoms of discomfort which encourage further intake of nicotine to relieve those symptoms. Many of the so-called 'positive' effects of smoking are in reality caused by the reduction of nicotine withdrawal symptoms. The strength of the withdrawal symptoms alongside the strong habit formation around smoking, leads to a very strong addictive effect.

Data from NICE, 2021, What withdrawal symptoms is a person likely to experience when they stop smoking?
Symptom of withdrawal How many affected How long it lasts
Cravings for nicotine 70% > 2 weeks
Appetite increase 70% > 10 weeks
Restlessness 60% < 4 weeks
Poor concentration 60% < 2 weeks
Depression 60% < 4 weeks
Irritability, anger, aggression 50% < 4 weeks
Poor sleep 25% < 1 week
Light headed 10% < 48 hours

Why does smoking cause addiction?

Smoking addiction has a two fold mechanism including the physical effects of nicotine withdrawal symptoms which are relieved by the next smoke, and the strong habit formation often around social situations, the routine of lighting up and often sharing a smoke.

What is meant by cravings?

Cravings are powerful urges to smoke. As well as being triggered in the situations where you would normally have smoked, they can be triggered by stress, seeing other people smoking, or becoming intoxicated (alcohol or drugs).

How can I handle cravings?

Before quitting, make a list of your own potential triggers and trigger situations, and how you can avoid them. Have a plan and be prepared to deal with the cravings and temptation.

Suggestions include:

  • Keeping busy.
  • Playing a game on a mobile phone.
  • Looking at the Smoke Free app or another 'support to quit' app.
  • Drinking a glass of water.
  • Changing the environment, for example going into another room or going outside.
  • Taking some brisk exercise.

Try not to relieve cravings by eating or having a sweet/biscuit/chocolate. Stopping smoking itself can often increase your general appetite, which can lead to unhelpful weight gain.

It can also be helpful to concentrate on the benefits of stopping smoking, both to your general health and your bank account. Remember the amount of money you are saving. Some people find it helps to have a plan to save that money towards something new or a holiday.

What cancers are linked to smoking?

Tobacco smoke causes about 90% of all lung cancers and 1/5th of all UK cancer diagnoses each year. More than 16 different cancer types are linked to smoking, including cancer in the nose and sinuses, mouth, lips, tongue, throat, voice box (larynx), gullet (oesophagus), lung, bladder, kidney, liver, stomach, pancreas, leukaemia, bowel, ovary, and cervix. Over a quarter of UK cancer deaths are linked to smoking. Newer research also links smoking with Hodgkin's lymphoma, prostate cancer, and cancer in the womb, vagina, and vulva.

What other health risks are there from smoking?

Smoking has also been shown to be among the main causes of heart disease, strokes, and circulation problems including aortic aneurysms. One year after stopping smoking the risk of having a heart attack is reduced by a half.

Several studies link smoking to the development of most types of dementia, including Alzheimer's disease.

Apart from lung cancer, the lungs can also be damaged causing bronchitis, COPD (chronic obstructive pulmonary disease), and pneumonia.

Smoking can make other chronic diseases like diabetes, asthma, many skin conditions and multiple sclerosis worse. Other smoking related health risks (heart disease, strokes, aneurysms, dementia etc.) are even higher in people who smoke and suffer from other chronic diseases including alcoholism.

I've smoked for years - isn't it too late to stop now?

It is never too late to stop smoking. A man of 30 who gives up smoking will live on average 10 years longer than if he continued to smoke. Stopping at 40 years of age adds 9 years, at 50 it adds 6 years, and at 60 will add 3 years to life expectancy. It does not matter at what age smoking is stopped it will always improve the chances of a longer life.

Does Champix contain lactose or gelatine?

No, there is no lactose or gelatin in Champix tablets.

Are there any health risks from e-cigarettes and vaping?

There have been some health concerns specific to e-cigarettes and vaping, due to the flavours, other additives and oil used in the vape liquid. Some additives including those causing so called 'popcorn lung' have been banned from UK vape fluids.

There are an increasing number of reports of young people who vape developing lipoid pneumonia, and lung damage due to inhalation of oils. As vaping and e-cigarettes are relatively new, further research is still needed to establish if there are long term health risks. Tobacco smoking had been established in the UK for 300 years before the serious health risks were proven!

Some e-cigarettes have been reported to explode or to catch fire.

Buy Champix tablets
Dr Amanda Wood

Authored 13 June 2022 by Dr A. Wood
MB ChB Manchester University 1984. NHS GP in Bristol. GMC no. 2855422

Reviewed by Dr C. Pugh, Dr B. Babor
Last reviewed 13 June 2022
Last updated 19 January 2024