How Chantix Works

How Chantix Helps You Quit Smoking

Stockbyte/Getty Images

What is Chantix and How Does it Work?

Varenicline tartrate is a prescription medicine that was developed by Pfizer, Inc. specifically to help people quit smoking. Marketed as Chantix, it works on two levels.

First, Chantix partially activates sites in the brain known as nicotinic acetylcholine receptors that are affected by nicotine. This gives new ex-smokers mild nicotine-like effects and eases symptoms of nicotine withdrawal.

Second, Chantix has the unique ability to neutralize the effects of nicotine if a person smokes while using this drug.

We'll take a look at how that occurs, but first let's review what happens when nicotine enters the brain.

How Nicotine Affects Brain Chemistry

Nicotine provides users with an almost immediate "kick" of euphoria that is the result of rapidly changing brain chemistry, and it starts within 7 seconds of the first puff on a cigarette.

When nicotine enters the brain, it docks with nicotinic acetylcholine receptors.  The nicotine molecule is very similar in shape to a neurotransmitter called acetylcholine, which affects many bodily functions, including breathing, heart rate, learning and memory. Acetylcholine also affects other neurotransmitters that have influence over appetite, mood, and memory. 

In the brain, nicotine binds with nerve cell receptor sites in places where acetylcholine would, creating the same effects.

Once attached, a release of dopamine is triggered.  

Dopamine is the neurotransmitter thought to be responsible for reinforcing the pleasure/reward associations people have with smoking. 

It is this chemical process that is thought to be responsible for addiction. Other addictive drugs such as cocaine, amphetamines and opioids also trigger the release of dopamine.

The acute effects of nicotine wear off within minutes, so people continue dosing themselves frequently throughout the day to maintain the pleasurable effects of nicotine and to prevent withdrawal symptoms.

How Chantix Affects Nicotinic Receptors

When Chantix is introduced into the brain, it targets a specific type of nicotinic receptor called alpha4beta2 nicotinic receptors.   It docks with these receptors, triggering a release of dopamine in the same way nicotine would, though not quite as much.  For ex-smokers, the effect is equal to a low to medium dose of nicotine that lasts until the drug wears off, which is several hours. 

In this way, Chantix helps to relieve symptoms of nicotine withdrawal that people experience when they quit smoking.

The added bonus here is that while Chantix is docked at these receptor sites, nicotine cannot do the same.  So, if a person decides to smoke a cigarette while they have Chantix in their system, the cigarette will not offer its usual "feel good" dopamine boost. Smoking will be a flat / dull experience, and quitting hopefully easier to achieve.

Is Chantix Effective?

Six clinical trials involving 3659 chronic cigarette smokers were used as a basis for the effectiveness of Chantix as a therapy for smoking cessation.

Five of the trials were randomized, placebo-controlled studies.  They showed that Chantix was more effective than a placebo to help people quit smoking. In two of the five trials, people using Chantix therapy (22 percent) were more successful at quitting smoking than those using Zyban (bupropion hydrochloride) (16 percent) as a quit smoking aid. For those taking a placebo, abstinence at the one year mark was approximately 8 percent.

In a study published in the Journal of the American Medical Association in January of 2016, researchers looked at 1086 people who quit smoking using one of the following three methods: Chantix,  the nicotine patch, or the patch and nicotine lozenges used in combination.

The results indicated that the three quit methods were similar in success rates at both six months and one year. 

At six months, 23 percent of participants who used the patch were still smoke-free, compared to 24 percent of those using Chantix, and 27 percent of people who used a combination of the patch and lozenges.  At one year, the success rate was 21 percent for the patch, 19 percent for Chantix and 20 percent for the combination method.

Other research has also shown that a combination of Chantix and the nicotine patch was more effective than using Chantix alone, though more studies are needed.

While the success rate may not seem like great odds, keep in mind the sheer number of people who are addicted to nicotine and dying because of it today. Globally, smoking-related disease causes nearly 6 million deaths every year.

Put another way, tobacco claims a human life every 5 seconds somewhere in the world. A drug that has the potential to help approximately 25 out of every 100 people using it to quit smoking is worth considering.

It's also important to have quit aid choices available to people who want to stop smoking, because what works for one might not work for the next person. Greater choice equals a greater chance for success, ultimately.

Is Chantix Safe to Use?

In the years since Chantix became available, a number of serious health concerns associated with its use have been identified:

Chantix is a prescribed medication because there can be significant side effects for a small percentage of the population.

If you're interested in using Chantix, have a discussion with your doctor to decide whether it might be a good choice for you.

What Do Ex-Smokers Who Have Used Chantix Think?

These comments were gathered from members of our smoking cessation support community who used Chantix to quit smoking.

Read through these testimonials with the perspective that they are personal opinions rather than hard facts.  Your experience with Chantix may be different than those offered here.

We are fortunate to live in a time when advances in medicine offer smokers more choices than ever before to quit smoking successfully. Nicotine addiction kills, plain and simple, and prescription quit aids like Chantix offer hope to those who might not have been able to quit smoking otherwise.


U.S. Food and Drug Administration. FDA Approves Novel Medication for Smoking Cessation. Accessed June 2016.

JAMA. Efficacy of Varenicline Combined With Nicotine Replacement Therapy vs Varenicline Alone for Smoking Cessation. July 9, 2014.

JAMA. Three Common Approaches to Smoking Cessation are Roughly Equal in Efficacy. January, 2016.

Pfizer. Chantix Safety Information.

Continue Reading