Dr Clare Morrison

Article by Dr Clare Morrison

How Does Champix Work?

What is Champix?

Champix – or Varenicline – is a prescription-only medicine that helps adults stop smoking.  Champix is based on a plant extract found in a variety of plants. It can also assist in reducing cravings and withdrawal symptoms that happen when you decide to stop smoking. Champix doesn’t contain nicotine and isn’t addictive.

How does Champix work?

Champix works by reducing the cravings and withdrawal symptoms associated with quitting smoking and blocking the effects of nicotine – which gives you a sense of pleasure when activated. When you smoke, the nicotine you inhale attaches to these receptors, sending a message to a different part of your brain to release a chemical called dopamine, which gives you a feeling of pleasure.

What are the side effects of Champix?

As with many drugs, Champix doesn’t come without any problems. Side effects tend to be mild and usually appear in the first week of taking the medicine. They include:

  • Mild nausea
  • Stomach or bowel problems
  • Headaches
  • Dizziness
  • Insomnia
  • Increased appetite

There have also been reports of heart attack and strokes in some people taking Champix – these can also be caused by smoking. Consult your doctor if you suffer from any of these conditions.

How do you take Champix?

A 12-week Champix prescription involves taking tablets once per day for the first three days and then twice a day until the end of week 12, every morning and evening. Champix should be taken after eating with a full glass (eight ounces) of water.

If you successfully stop smoking after 12 weeks, treatment is often stopped. However, in some cases, 12 weeks of treatment could be advised. In such cases, a tapering off of the dose over a week or so could help. This is because otherwise there could be an increase in irritability, an urge to smoke, depression and/or insomnia. If you haven’t succeeded after 12 weeks, there is little point in continuing with the medication.

Champix is proven to work

  • In a study, over a thousand patients were enrolled to test Champix – and tests were also duplicated in a similar clinical trial.
  • Patients received either Champix 1 mg twice a day, Zyban 150 mg twice a day, or sugar pills twice a day for 12 weeks. Patients were also given a booklet on quitting smoking and received counselling at each visit.
  • In studies, 44 percent of Champix users quit during weeks 9 to 12 of treatment in comparison to 18 percent on the sugar pill and Champix also dampened the urge to smoke. Patients were considered to have quit if they didn’t smoke a cigarette or use other nicotine products for the final four weeks of treatment.

For more information get in touch with MedExpress’s customer service team – they can help you with your queries. You can also purchase Champix.

Dr Clare Morrison
Dr Clare Morrison
Experienced General Practitioner in Hampshire since 1995, with particular interest in Nutrition, Obesity and Smoking Cessation.
Originally published August 17 2017, updated March 10 2020