The Independent Pharmacy

How Does Champix Work? What You Need To Know About The Smoking Treatment

Scott McDougall
Scott McDougallMPharmDirector & Registered Manager

Reviewed on 19 Aug 2022

Quitting smoking is hard, but these days there are many different kinds of treatments available over-the-counter or on prescription that can help you to beat your addiction, like Champix. If you’re thinking about using Champix tablets, you’re probably wondering: how does Champix work?

That’s why we’ve created this Champix guide — so that you can find out more about this popular prescription-only smoking cessation treatment.

We’ll be covering everything from how Champix works, to the Champix success rate and comparing it to other treatments like Zyban.

What is Champix?

Champix is a prescription-only medicine which is used to stop smoking, by helping to reduce withdrawal cravings and blocking the rewarding effects of nicotine when you smoke.

The active ingredient that Champix contains is varenicline. We’ll go more into how this drug works in the section below.

Champix is a popular treatment for those wishing to stop smoking because it is so effective. Using this medicine as part of a smoking programme dramatically increases your chances of quitting.

Champix is available as a starter pack which contains 0.5mg and 1mg tablets, as well as a continuation pack (which contains just 1mg tablets). To find out more about the different strength tablets of Champix, visit our Champix dose page.

You can buy both types of Champix packs here from The Independent Pharmacy following a free online consultation with one of our medical team.

Champix Tablets
Champix Tablets
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How does Champix work?

If you’re considering taking this medicine, you’ll probably want to know how it works to stop you from smoking. So how does Champix work?

Champix works in two ways:

  • It reduces cravings for nicotine in the same way that NRTs (Nicotine Replacement Therapy) do
  • It blocks the rewarding and reinforcing effects of smoking

When you smoke, nicotine from your cigarette attaches itself to receptors in the brain, which releases dopamine (a ‘happy’ chemical) and gives you the euphoric feeling associated with smoking.

Champix works in a similar way — by attaching to the same receptors and releasing dopamine too. This mimics the effect of nicotine on the body, and stops you from feeling the withdrawal symptoms and cravings that are associated with quitting smoking.

Champix also blocks the effects of nicotine. Because varenicline (the active ingredient in Champix) is already attached to the receptors in your body, nicotine is prevented from attaching properly. So even if you have nicotine in your system from smoking, it can’t create that happy feeling that smoking normally elicits.

The result of this is that there is no big increase in dopamine levels after you smoke, which stops the normal feelings of pleasure after a cigarette, ultimately reducing the rewarding and reinforcing effects of smoking.

Champix also has very few side effects. You can find out more about possible adverse effects and what to expect on our Champix side effects page.

Does Champix work?

Yes, Champix does work very well when it comes to quitting smoking. In the section below, you’ll be able to read more about Champix success rates and how effective it really is.

Don’t just take our word for it, either. To read reviews and feedback from real users, head to our Champix reviews page. We’ve collected all of the feedback about this medicine from customers of The Independent Pharmacy so that you can read up on what people are saying and get a feel for how most users get on with Champix.

Champix success rate

The Champix success rate is among the highest success rates of any smoking cessation aid.

Research suggests that Champix is the most effective medicine for people looking to stop smoking, which is why it is so popular.

According to clinical study data, Champix has been shown to more than double your chances of quitting smoking permanently. About one in five people succeed in stopping smoking with Champix, compared with about one in 10 who try to stop without using Champix.

How long does Champix take to work?

Champix is normally a 12-week course of treatment. Therefore, this is how long Champix takes to work.

In some cases, it may be necessary to continue your Champix treatment course for another 12 weeks. This is generally if you have not found your treatment course successful and you are still struggling to quit smoking. If this is the case, speak to your doctor or pharmacist — they may suggest extending your treatment.

In other situations, your doctor may recommend tapering down your Champix dose slowly over the course of a week to help reduce the risk of side effects or smoking urges.

In general, you should be able to feel the effects of Champix after the first week, as the drug starts to build up in your body, helping to reduce cravings and blocking the effects of nicotine if you do smoke.

By the time you have set your ‘stop date’ between day 8 and day 14 of treatment, there will be enough Champix in your system to prevent cravings and withdrawal symptoms.

Is Champix good for quitting smoking?

Yes, Champix is good for quitting smoking. As you can see in the Champix success rate section above, using Champix is shown to more than double your chances of quitting smoking for good.

However, you still need to have willpower to quit smoking, even with Champix. Using this medicine alone — or any other smoking cessation treatment — doesn’t guarantee success. You have to be able to resist the temptation to smoke and halt your usual smoking habits.

Zyban or Champix: which is best?

There are two main prescription-only smoking cessation options: Champix and Zyban.

Zyban — which is the brand name for the drug Bupropion — can also help you to quit smoking by reducing your withdrawal symptoms and smoking urges. It isn’t clear exactly how this medicine works when it comes to quitting smoking, but it is thought to alter chemicals in the brain so that nicotine is less effective.

Zyban can be a good option for a smoking cessation treatment but it isn’t as effective as Champix.

Champix has a higher success rate, so it is considered better than Zyban and recommended by doctors and pharmacists as the first choice for smoking cessation medicine.

What happens when you stop taking Champix?

Nothing should really happen when you stop taking Champix.

Once your full treatment course of Champix is complete, you can stop taking it and it is not generally necessary to taper down the dose.

However, some people may want to gradually reduce their Champix dose towards the end of their treatment course rather than stopping suddenly. This can help to fight the urge to smoke as well as decreasing the possibility of side effects such as increased irritability and sleep disturbance.

Speak to your doctor or pharmacist about this — they may suggest steadily coming off Champix if suitable for you.

Why is Champix not working?

As we’ve mentioned above, although Champix makes giving up smoking easier, it is no substitute for willpower.

Unless you are motivated to do so, you are unlikely to be able to completely quit smoking while taking Champix.

If you’re going to stop smoking, you need to be committed to following your treatment programme, which includes setting a ‘stop date’, completely committing to not smoking even in times of stress, and getting support from your GP, pharmacist or a trained stop smoking advisor.

How long before Champix leaves your system?

Champix takes roughly five to seven days to leave your system.

The elimination half-life of Champix is approximately 24 hours. The half-life of a medicine is the time it takes for the amount of it in your body to be reduced by half. This means it takes roughly a day after the last time you take Champix for you to eliminate 50% of the drug from your system.

Based on this, it is estimated that at least some Champix will remain in your system for an average of five to seven days after your last dose. After this, it will be completely out of your system.


Champix is an effective prescription-only medicine which is used to stop smoking. The active ingredient in Champix is varenicline.

It works in two ways: by helping to reduce nicotine cravings and blocking the rewarding effects of smoking. Champix does this by attaching to the same receptors in the brain that nicotine normally does, which helps to stop ‘cold turkey’ feelings and withdrawal symptoms.

Champix is a popular smoking cessation treatment because it is very effective — using this medicine has been shown to more than double your chances of quitting smoking for good.

You can buy Champix tablets here at The Independent Pharmacy. It’s quick and easy to do — you just need to answer a few questions via our online consultation form. Once you do, one of our qualified prescribers can approve your order and get your treatment prepared for delivery the very next day.


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