CHAMPIX: COMPLETE GUIDE TO VARENICLINE FOR SMOKING CESSATION

Quitting smoking ranks among the most challenging health decisions you’ll ever make, but you don’t have to face nicotine addiction alone. While tobacco smoking remains a leading cause of preventable illness worldwide, affecting tens of thousands of people annually, modern medicine offers powerful tools to help you stop smoking successfully.

Champix represents one of the most effective smoking cessation treatments available today, with clinical evidence showing it can help people quit smoking at rates significantly higher than other medications. Whether you’re a regular smoker looking to quit or someone who’s tried stopping smoking before without success, understanding how this prescription medication works could be your vital step toward stopping completely.

This comprehensive guide covers everything you need to know about Champix / varenicline, from its unique mechanism of action to practical information about accessing treatment through NHS stop smoking services. We’ll explore the medication’s effectiveness, safety profile, and how it compares to other smoking cessation treatments and E-Cigarettes available today.

Key Takeaways

• Champix (varenicline) is a prescription medication proven to help people quit smoking by reducing cravings and withdrawal symptoms

• The medication works by blocking nicotine receptors in the brain while partially stimulating them to ease withdrawal

• Clinical studies show Champix helps about 1 in 4 people stop smoking for at least six months when combined with behavioural support

• Treatment typically lasts 12 weeks and should be started 1-2 weeks before your planned quit date

• Champix and varenicline are the same medication - Champix is the brand name while varenicline is the generic version

• The NHS now offers varenicline through Stop Smoking Services after the original Champix was withdrawn in 2021

What is Champix (Varenicline)?

Champix is a prescription-only medication specifically designed to help people quit smoking through a unique approach that directly targets nicotine dependence in the brain. Unlike nicotine replacement therapy options that provide controlled amounts of nicotine, this medication works by interfering with how nicotine affects your brain’s reward system.

The active ingredient in Champix is varenicline tartrate, a compound developed specifically for smoking cessation treatment. Originally created by pharmaceutical company Pfizer, the medication underwent extensive clinical trials before gaining approval in multiple regions worldwide. The drug was initially marketed under different brand names - Champix in Europe and other regions, and Chantix in the United States.

In 2021, the original branded pill was withdrawn from the UK and other markets due to the detection of nitrosamine impurities during manufacturing. However, great news for people seeking cessation treatment: generic medicines containing the same active ingredient are now available. Teva UK has developed a generic version that maintains the same effectiveness as the original formulation, and this is now offered through NHS England’s Stop Smoking Services.

The medication represents a significant advancement in smoking cessation science because it doesn’t simply replace nicotine or act as a general mood stabiliser. Instead, varenicline was designed specifically to target the neurochemical pathways involved in nicotine addiction, making it one of the most targeted approaches to helping people stop smoking available today.

Clinical research has consistently demonstrated that Champix is more effective than other smoking cessation treatments, including bupropion (Zyban) and single-agent nicotine replacement therapies. This superior effectiveness, combined with its specific mechanism of action, has made varenicline treatment a first-line recommendation from health authorities and medical professionals worldwide.

How Does Champix Work?

Understanding how does Champix work requires looking at what happens in your brain when you smoke and how nicotine creates addiction. When you inhale tobacco smoke, nicotine quickly reaches your brain and binds to specific nicotine receptors called α4β2 neuronal nicotinic acetylcholine receptors. This binding triggers the release of dopamine, creating the pleasurable effects that reinforce smoking behaviour and make quitting so challenging.

Champix work through a sophisticated dual mechanism that addresses both sides of nicotine addiction. The medication acts as what scientists call a “partial agonist” at these crucial nicotine receptors. This means it both stimulates and blocks the same receptors that nicotine targets, but in a more controlled way.

When you take varenicline, it binds to the α4β2 receptors with very high affinity - over 500 times more selective for these specific receptors than others. Once bound, it provides moderate stimulation that releases about 50% of the dopamine that nicotine would produce. This partial stimulation helps ease withdrawal symptoms like feeling irritable, anxiety, and difficulty sleeping that make quitting so challenging.

Simultaneously, because varenicline occupies these receptors, it blocks nicotine from binding when you do smoke. This reduces the pleasure derived from cigarettes significantly, making smoking less rewarding and reinforcing. Even if you relapse during treatment, cigarettes won’t provide the same satisfying effects they once did.

The medication’s specificity is remarkable - varenicline is more than 2,000 times more selective for nicotine receptors than for non-nicotinic receptors, minimising off-target effects. Clinical pharmacology studies confirm that this mechanism results in substantially lower dopamine release compared to nicotine itself, effectively reducing cravings while blocking the reward cycle that maintains addiction.

This dual approach of reducing cravings while diminishing smoking rewards creates an ideal environment for successful cessation. Unlike treatments that only address one aspect of addiction, Champix tackles both the physical withdrawal and the psychological reinforcement that makes tobacco smoking so addictive.

How to Use Champix

Starting treatment with Champix requires careful planning and adherence to a specific schedule designed to maximise your chances of success. The standard varenicline treatment course lasts 12 weeks, though some people may benefit from extending treatment to 24 weeks if additional support is needed.

The key to successful treatment is beginning Champix one to two weeks before your planned quit smoking date. This pre-loading period allows the medication to build up in your system and start blocking nicotine receptors before you actually stop smoking. During this time, you can continue smoking normally while your brain adjusts to the medication.

Champix tablets are taken twice daily with food to minimise common side effects, particularly nausea. Taking the medication with meals significantly reduces the likelihood of experiencing stomach upset and can help prevent vivid dreams that some users report. The starter pack typically includes different dosing strengths to gradually introduce the medication to your system.

Here’s the typical dosing schedule:

Days	Morning Dose	Evening Dose	Notes
1-3	0.5mg	None	Starting dose
4-7	0.5mg	0.5mg	Increase to twice daily
8+	1mg	1mg	Maintenance dose

Your quit date should fall between days 8-14 of starting treatment. On your quit date, you stop smoking completely while continuing the medication as prescribed. This timing ensures that varenicline has reached optimal levels in your bloodstream when you face the greatest challenges of nicotine withdrawal.

Consistency is crucial for success. Take your tablets at the same times each day, and don’t skip doses even if you experience minor side effects initially. If you forget a dose, take it as soon as you remember, but don’t double up if it’s almost time for your next scheduled dose.

When completing your course of treatment, gradually tapering the dose is recommended rather than stopping abruptly. This helps minimise the risk of withdrawal symptoms and maintains the medication’s protective effects as your brain fully adjusts to functioning without nicotine.

Effectiveness and Success Rates

The clinical evidence supporting Champix’s effectiveness in helping people quit smoking is substantial, with multiple large-scale studies demonstrating superior results compared to other smoking cessation treatments. The most significant finding across numerous trials is that approximately 1 in 4 people using Champix alongside behavioural support successfully maintain abstinence from smoking for at least six months.

This success rate represents a remarkable improvement over other treatment options. Clinical trials consistently show that varenicline provides nearly double the odds of quitting compared to bupropion (Zyban), another prescription smoking cessation aid. When compared to placebo treatments, Champix demonstrates more than three times the effectiveness in both 12-week and 40-week studies.

One of the most comprehensive studies supporting these findings was the EAGLES trial, one of the largest comparative studies of smoking cessation treatments ever conducted. This research reinforced that varenicline achieves higher rates of continuous abstinence at both 12 and 24 weeks compared to bupropion and nicotine replacement therapy when used alone. (1)

The medication’s effectiveness extends beyond just initial quit attempts. Long-term studies tracking participants for up to a year show sustained benefits, with many people who successfully quit with Champix remaining smoke-free well beyond their treatment period. This durability suggests that the medication provides lasting changes in how the brain responds to nicotine cravings.

Health authorities have recognised these impressive results in their recommendations and projections. The NHS England estimates that widespread varenicline prescribing could help more than 85,000 people quit smoking annually (2). Public health projections suggest this could prevent approximately 9,500 smoking-related deaths over a five-year period, highlighting the significant population-level impact of making this treatment widely available.

The National Institute for Health and Care excellence (NICE) has endorsed varenicline as a cost-effective intervention, noting that the medication’s high success rates justify its inclusion in smoking cessation services. When combined with behavioural support through cessation services, the treatment represents one of the most effective approaches available for people seeking to overcome nicotine addiction.

Side Effects and Safety Information

Like all medications, Champix can cause side effects, though most people tolerate the treatment well throughout their course. Understanding potential side effects helps you prepare for treatment and know when to seek medical advice, ensuring you can complete your smoking cessation journey safely.

The most common side effects include nausea, which affects up to 30% of users, particularly during the first few weeks of treatment. Taking tablets with food significantly reduces this risk and is why healthcare providers emphasise eating before each dose. Other frequently reported effects include headache, difficulty sleeping, and changes in appetite that may overlap with normal nicotine withdrawal symptoms. (3)

Many users experience vivid dreams or unusual sleep patterns during treatment. While these can be unsettling, they typically diminish as your body adjusts to the medication. If sleep disturbances become problematic, taking your evening dose earlier in the day or discussing timing adjustments with your healthcare provider can help.

Some people report nasal or throat inflammation, which usually resolves without intervention. Changes in taste or digestive discomfort may also occur but tend to be mild and temporary. It’s important to recognise that some symptoms commonly attributed to Champix actually represent normal withdrawal symptoms that occur when stopping smoking, regardless of the cessation method used.

Neuropsychiatric symptoms deserve special attention and monitoring. Some users may experience mood changes, increased anxiety, or depression during treatment. While large meta-analyses have found these risks to be lower than initially suspected, particularly in people without prior psychiatric medical history, any significant mood disturbances warrant immediate medical consultation.

The regulatory authority emphasises the importance of monitoring for severe mood changes, including thoughts of self-harm. If you experience depression, anxiety, or suicidal thoughts while taking Champix, contact your healthcare provider immediately. These effects appear to be more common in people with existing mental health issues, which is why careful screening occurs before starting treatment.

Most side effects are manageable with proper preparation and medical guidance. The vast majority of people who experience side effects find them tolerable enough to complete their full course of treatment, leading to successful smoking cessation that far outweighs temporary discomfort.

Who Cannot Take Champix

While Champix represents an excellent cessation treatment option for many people, certain groups cannot safely use the medication due to contraindications and safety concerns. Understanding these restrictions ensures appropriate treatment selection and prevents potential health complications.

The medication is not approved for people under 18 years of age, as safety and effectiveness have not been established in poediatric populations. Young people seeking smoking cessation support should explore other options through specialised youth cessation services that offer age-appropriate interventions and support.

Pregnancy and breastfeeding represent absolute contraindications for Champix use. The medication’s safety during pregnancy has not been established, and animal studies have indicated potential developmental risks (4). Since tobacco smoking during pregnancy poses well-documented risks including foetal oxygen deprivation, low birth weight, preterm birth, and developmental complications, pregnant smokers should prioritise quitting but through safer methods.

The NHS provides specialised support for pregnant smokers, including behavioural interventions and carefully monitored nicotine replacement therapy under medical supervision. These approaches offer safer alternatives that still significantly improve outcomes for both mother and baby compared to continued smoking.

People with known hypersensitivity to varenicline or any tablet ingredients should not use Champix. Allergic reactions, while rare, can be serious and require immediate medical attention. Your healthcare provider will review your allergy history before prescribing the medication.

Mental health considerations require careful evaluation. While Champix is not automatically contraindicated in people with psychiatric conditions, it’s generally not recommended for those with active or untreated severe depression, bipolar disorder, or past suicidal behaviour. However, this doesn’t mean people with mental health conditions cannot benefit from varenicline - rather, it requires careful risk-benefit assessment alongside psychiatric consultation.

People with seizure disorders, epilepsy, or severe kidney disease need special consideration and potentially modified dosing regimens. These conditions don’t necessarily prevent Champix use but require close medical supervision and possible dose adjustments based on individual circumstances.

The key principle is that smoking cessation benefits nearly everyone’s health, but treatment selection must be individualised. If Champix isn’t appropriate for your situation, alternative smoking cessation treatments remain available through smoking services, ensuring you still have effective options for quitting smoking.

Drug Interactions and Precautions

One of Champix’s advantages is its relatively clean interaction profile with most commonly prescribed medications. Unlike some smoking cessation treatments that significantly affect liver enzymes or interact with numerous drugs, varenicline has few clinically significant drug interactions, making it suitable for people taking multiple medications.

The most important interaction to avoid is combining Champix with nicotine replacement therapy products such as nicotine patches, gum, or lozenges. This combination is not recommended because varenicline’s mechanism involves blocking the same nicotine receptors that replacement therapies target. Using both treatments simultaneously may increase side effect risks without providing additional benefits, and varenicline’s receptor blocking action could reduce NRT effectiveness.

If you’re currently using nicotine replacement products, you’ll need to stop these before starting Champix. Your healthcare provider will help you plan this transition to ensure continuous support during your quit attempt without dangerous combinations.

An important consideration that many people overlook is how quitting smoking itself can affect other medications you’re taking. Tobacco smoking induces certain liver enzymes that metabolise drugs, so when you stop smoking, your body may process some medications differently. This particularly affects insulin for diabetes management, theophylline for respiratory conditions, and warfarin for blood clotting.

If you take any of these medications, your healthcare provider will monitor your levels more closely during and after your quit attempt, potentially adjusting doses as your body adapts to functioning without tobacco smoke. This monitoring ensures your other health conditions remain well-controlled while you focus on smoking cessation.

Alcohol interactions deserve special mention. While there are no direct pharmacological interactions between Champix and alcohol, many users report reduced alcohol tolerance while taking the medication. You may find that you feel the effects of alcohol more strongly than usual, so monitoring your alcohol consumption carefully during treatment is advisable.

Some people also report changes in how alcohol affects their mood while taking varenicline. If you notice unusual reactions to alcohol or find that drinking triggers stronger urges to smoke, consider reducing or avoiding alcohol during your treatment period to maximise your chances of success.

Before starting treatment, arm your healthcare provider with a complete list of all medications, supplements, and herbal products you’re taking. This ensures they can identify any potential issues and provide appropriate guidance for your specific situation.

Champix vs Other Smoking Cessation Treatments

Understanding how Champix compares to other smoking cessation treatments helps you make informed decisions about the best approach for your quit attempt. Each treatment option has distinct mechanisms, effectiveness rates, and suitability for different people and circumstances.

Nicotine replacement therapy remains one of the most widely used approaches, delivering controlled amounts of nicotine through patches, gum, lozenges, inhalers, or nasal sprays. While NRT helps manage withdrawal symptoms by providing nicotine without the harmful combustion products in cigarettes, it works differently than Champix. Single-agent NRT typically shows lower success rates than varenicline, though combination NRT (such as patches plus gum) approaches Champix’s effectiveness in some studies.

Bupropion, marketed as Zyban for smoking cessation, represents another prescription option. This medication works primarily as an antidepressant that also reduces nicotine withdrawal symptoms and cravings. However, clinical trials consistently demonstrate that Champix achieves nearly double the quit rates of bupropion, making varenicline the more effective prescription choice for most people.

Cytisine offers an interesting comparison as it works through a similar mechanism to Champix, acting as a partial agonist at nicotine receptors. This plant-derived compound provides a shorter 25-day treatment course and has shown good efficacy in trials. However, cytisine is less commonly prescribed in the UK and has less extensive clinical data than varenicline.

E-cigarettes occupy a unique position in the smoking cessation landscape. Unlike prescription medications, e-cigarettes are consumer products that deliver nicotine through vapour rather than combustion. While some people successfully use e-cigarettes to quit smoking, they’re not regulated as medicines and lack the extensive clinical trial evidence that supports Champix. With that said, the largest review of evidence to-date, conducted by Cochrane, found 'high-certainty' evidence that E-Cigarettes are more effective for quitting smoking than typical nicotine replacement therapy products like patches and gum. (5)

The choice between treatments often depends on individual circumstances, medical history, and preferences. People with certain mental health conditions might be better suited to NRT or bupropion, while those seeking the highest likelihood of success often benefit from Champix alongside behavioural support. Some people may need to try multiple approaches before finding what works best for them.

What sets Champix apart is its specific design for nicotine addiction and its ability to both reduce cravings and block smoking rewards simultaneously. This dual action, combined with robust clinical evidence showing superior effectiveness, explains why health authorities like the National Institute for Health and Care Excellence recommend varenicline as a first-line treatment for smoking cessation. 

NHS Availability and Access

The return of varenicline to UK healthcare represents a significant development for people seeking effective smoking cessation support. After the original Champix was withdrawn in 2021 due to manufacturing impurities, NHS England worked to ensure continued access to this proven treatment through alternative suppliers.

Generic varenicline from Teva UK became available through NHS Stop Smoking Services in 2024, marking the restoration of what many consider the most effective smoking cessation medication. The generic version contains the same active ingredient as the original Champix and has been thoroughly reviewed and approved by the Medicines and Healthcare products Regulatory Agency for safety and efficacy.

Accessing varenicline through the NHS is straightforward and designed to remove barriers that might prevent people from getting help. You can self refer to local smoking services through the NHS Better Health website, which connects you with support in your area. This self-referral process means you don’t need to wait for a GP appointment to begin your quit journey, though involving your regular healthcare provider in your quit plan is always beneficial.

NHS Stop Smoking Services provide varenicline alongside behavioural support, recognising that medication works best when combined with professional guidance and encouragement. These services employ trained specialists who understand both the pharmacological and psychological aspects of smoking cessation, providing comprehensive support throughout your treatment journey.

The cost-effectiveness of providing varenicline through the NHS has been extensively analysed and endorsed by NICE. Health economists project that widespread access to this treatment could prevent thousands of smoking-related deaths over a five-year period while reducing healthcare costs associated with many major health conditions linked to tobacco use.

Different regions may have slightly different processes for accessing varenicline, but the principle remains consistent across England. Some areas offer group support sessions, others provide individual consultations, and many now offer telephone or video support to accommodate different preferences and circumstances.

Making varenicline available through NHS services represents recognition that smoking cessation is a medical issue requiring medical solutions. Rather than viewing quitting as purely a matter of willpower, the NHS approach acknowledges that nicotine addiction involves brain chemistry changes that benefit from pharmaceutical intervention combined with professional support.

The availability of generic versions also helps ensure sustainable access to this treatment. Unlike branded medications that can face supply disruptions or pricing pressures, generic medicines typically offer more stable availability and cost-effectiveness for healthcare systems.

Pregnancy and Breastfeeding Considerations

Pregnancy creates a unique and urgent situation for women who smoke, where the benefits of quitting smoking are enormous, but treatment options become more limited due to safety concerns for the developing baby. Champix is not recommended during pregnancy or while breastfeeding, as its safety in these populations has not been established through appropriate clinical studies.

The urgency of smoking cessation during pregnancy cannot be overstated. Tobacco smoking during pregnancy creates serious risks including reduced oxygen delivery to the developing baby, increased likelihood of low birth weight, higher rates of preterm birth, and various developmental complications. These well-documented risks make smoking cessation one of the most important health interventions during pregnancy.

Animal studies of varenicline have suggested potential developmental risks, which led regulatory authorities to recommend avoiding the medication during pregnancy. While these studies don’t definitively predict human outcomes, the precautionary principle guides medical recommendations when safer alternatives exist.

Pregnant women seeking to quit smoking should access specialised NHS support designed specifically for their situation. These services understand the unique challenges and urgency of pregnancy-related smoking cessation and can provide intensive behavioural support that proves highly effective when properly delivered.

Nicotine replacement therapy may be considered during pregnancy under careful medical supervision, typically when the benefits of successful quitting outweigh potential risks from continued smoking. This decision requires individual assessment involving the woman, her midwife or obstetrician, and smoking cessation specialists.

The NHS provides specialised pathways for pregnant smokers, often involving midwifery teams trained in smoking cessation techniques. These services recognise that pregnancy can provide powerful motivation for behaviour change, and they’re designed to harness this motivation while providing appropriate medical support.

Partners and family members play crucial roles in supporting smoking cessation during pregnancy. If a partner smokes, this significantly increases the difficulty of quitting and the likelihood of relapse. Family-centred approaches that address household smoking behaviours often prove more effective than focusing solely on the pregnant woman.

Planning for pregnancy also creates opportunities for smoking cessation. Women planning to conceive who currently smoke should ideally quit before becoming pregnant, allowing them to use the full range of available treatments including Champix. Pre-conception smoking cessation removes risks to early foetal development and establishes healthy behaviours before pregnancy begins.

Champix: Complete Guide to Varenicline for Smoking Cessation - Conclusion

Champix represents a significant advancement in smoking cessation treatment, offering people a scientifically proven tool to overcome nicotine addiction through targeted brain chemistry intervention. With success rates of approximately 1 in 4 people maintaining abstinence for at least six months when combined with behavioural support, the medication provides hope for those who have struggled with previous quit attempts. Sadly it isn't for everyone and, as there are strong links between smoking and mental illness, the side effects from varenicline could rule it out as a treatment for smokers struggling with their mental health.

The key to success with any smoking cessation treatment lies in combining action with comprehensive support. NHS Stop Smoking Services provide this integrated approach, recognising that overcoming addiction requires addressing both the physical and psychological aspects of nicotine dependence. This is why studies on E-Cigarette use with behavioural support indicate that E-Cigarettes could be up to twice as effective for quitting smoking compared with traditional nicotine replacement products.

So - if you are a smoker looking to quit but are concerned over side effects from varenicline, consider making the switch to E-Cigarettes! E-Cigarettes provide the hand-to-mouth action smokers are so used to, while providing nicotine in a similar way to smoking a cigarette - just with 95% of the harm removed (according to Public Health England) (6). Vaping a flavour you enjoy can really help to make vaping a more attractive choice than smoking - so head on over to our starter kit deals page and grab a SMOKO starter kit for free when you buy a box of refills!

FAQ

Are Champix and varenicline the same medication?

Yes, Champix and varenicline contain the same active ingredient (varenicline tartrate) and work identically to reduce cravings and withdrawal symptoms. Champix was the original brand name developed by Pfizer, while varenicline is the generic version now available through the NHS after the branded product was withdrawn in 2021. Both medications target nicotine receptors in the brain using the same mechanism and deliver the same therapeutic effects. The only difference lies in the manufacturer and branding - the generic version from Teva UK provides the same clinical benefits as the original Champix formulation.

How long does Champix treatment last?

The standard varenicline treatment course lasts 12 weeks, beginning 1-2 weeks before your planned quit date to allow the medication to reach optimal levels in your system. Some people may benefit from extending treatment to 24 weeks if additional support is needed to maintain their quit attempt. Your healthcare provider will determine the appropriate duration based on your individual response and progress. Research shows that completing the full recommended course provides the best chances of long-term success, even if you experience minor side effects during treatment.

Can I use Champix with nicotine replacement therapy?

No, Champix should not be combined with nicotine replacement products such as patches, gum, or lozenges. This combination can increase the risk of side effects without providing additional benefits. Champix works by blocking the same nicotine receptors that replacement therapies target, so using both treatments simultaneously would be counterproductive. The medication’s receptor-blocking action could actually reduce the effectiveness of NRT. Choose one smoking cessation method at a time for both safety and optimal effectiveness. If you’re currently using NRT, you’ll need to stop before starting Champix.

What should I do if I experience side effects?

Contact your healthcare provider if you experience severe or concerning side effects, particularly mood changes, depression, or thoughts of self-harm. Seek immediate medical attention for any psychiatric symptoms, as these require prompt evaluation and possible treatment adjustment. For common side effects like nausea, taking tablets with food often provides relief. Vivid dreams and sleep disturbances typically improve as your body adjusts to the medication. Don’t stop treatment abruptly without medical guidance - your healthcare provider can help you manage side effects or adjust your treatment plan while maintaining support for your quit attempt. Many side effects are temporary and resolve as treatment continues.

REFERENCES

(1) Neuropsychiatric safety and efficacy of varenicline, bupropion, and nicotine patch in smokers with and without psychiatric disorders (EAGLES): a double-blind, randomised, placebo-controlled clinical trial

(2) NHS England offers an improved stop-smoking pill to help people quit

(3) NHS: Side effects of varenicline

(4) Varenicline Pregnancy and Breastfeeding Warnings

(5) Latest Cochrane Review finds high certainty evidence that nicotine e-cigarettes are more effective than traditional nicotine-replacement therapy (NRT) in helping people quit smoking

(6) E-cigarettes around 95% less harmful than tobacco estimates landmark review

ABOUT THE AUTHOR

Written by Dan Overgage 

Dan Overgage is a former smoker of 10 years until he became a client of SMOKO E-Cigarettes.  Dan started working with SMOKO 5 years ago after successfully quitting using our e-cigarettes and works across our Customer Service and heads up our content creation and research with a strong focus on all things quitting smoking.  During his tenure with SMOKO, Dan has written countless blogs and consults with countless clients every day to help them to stay smoke-free.