Zyban (bupropion) is one of only two prescription medications that are FDA-approved to help people quit smoking. (Varenicline, marketed as Chantix, is the other.) Zyban is the formulation of bupropion that is approved for smoking cessation, and unlike nicotine replacement products like the patch, it does NOT contain nicotine.
(Wellbutrin is an antidepressant medication with bupropion as the active ingredient.)
Meta analytic research, which computes the outcomes from multiple high-quality research studies, showed that about twice as many people who got bupropion were able to quit and stay quit compared to people who got a placebo or 'fake' medicine. In these studies, the participants in both the treatment group and in the control group were on a behavioral plan in addition to the drug or placebo.
A Note About Effectiveness
The most effective of all of the stop smoking aids or drugs have shown about a 'doubling' effect. That means that if you use an 'effective' medication or aid, on average you are about twice as likely to quit successfully as someone who tries to quit without it. What it DOES NOT mean is that the medication alone will "make" you quit.
For example, only about 5% of people who try to quit cold turkey are successful. So if you use a medication that doubles your chances and then try to quit cold turkey, your chance of quitting successfully ― even WITH the medication ― is only about 10%.
I mention this here because it's important to understand what the word 'effective' means when it comes to quit smoking medications, including bupropion. The bottom line is, to increase your chances of quitting successfully, you'll need to combine whatever you choose with the best quit smoking plan or program you can find. See 'My Recommendations' below for more advice and links related to this.
How It Works
Bupropion was originally developed as an antidepressant (brand name Wellbutrin) and only later discovered to help people quit smoking. 'Zyban' is the brand name of the bupropion formulation that is approved for smoking cessation. How it works exactly to help people quit smoking hasn't been proven, but it may work by partially reducing the effect of nicotine in the brain, and reducing some withdrawal symptoms. An explanation of its chemical properties provides some clues.
Warning: The information below may fall into the category of 'Way More Than You Wanted to Know' about bupropion. If you're not interested in a technical explanation of the possible mechanism of action, feel free to skip ahead to 'How to Use Zyban'...
Bupropion acts on two types of neurotransmitters: norepinephrine and dopamine. For both norepinephrine and dopamine, bupropion acts as a 'reuptake inhibitor' [that is, it keeps the cell from taking the neurotransmitter back in] which has the effect of keeping that neurotransmitter circulating, and increasing its effect. You can think of the effects of norepinephrine and dopamine as similar to adrenaline - both dopamine and norepinephrine act on the sympathetic nervous system to increase heart rate, glucose release, and other sympathetic nervous system responses. Bupropion increases these effects. It's not clear how these effects contribute to bupropion's ability to help people quit smoking, but it may be related to the dopamine effect.
Nicotinic receptors in the brain (those that respond to nicotine), when stimulated, act in part to stimulate the mesolimbic dopamine system, which scientists believe is the neuronal mechanism for the 'reward' experienced upon smoking. It may be that the dopamine-related effect of bupropion acts to mask the effect of this stimulation, thereby reducing the 'reward' experienced as a result of nicotinic stimulation, which ultimately should make it easier to quit.
Keep in mind that the 'reward' of nicotine in the brain is only one part of the physical and psychological addiction to nicotine and smoking more generally.
(BTW, you may read elsewhere that bupropion acts as a nicotinic antagonist - however, the clinical pharmacology information on bupropion published by the FDA does NOT indicate this.) [enter 'zyban' into the search box.]
Using Zyban is pretty simple: It comes in pill form that you take once a day initially, and then twice a day. Generally you begin taking it a week or two before the day you plan to quit in order to build up to its maximum effect. Your doctor may have you continue on Zyban for another 2 to 3 months after you quit.
Of course, you shouldn't expect the little pill to do all the work by itself ― you'll want to combine it with a good behavioral program for quitting, as well. (See My Recommendations below for more on this.)
The most common side effects of Zyban (bupropion) are headaches, nausea, dry mouth, and sleep disturbances. For most people these are relatively minor effects that go away when they quit taking the medication.
An important potential risk with bupropion is increased risk of seizures. If you suffer from epilepsy, alcoholism, or any psychiatric condition, including an eating disorder, or if you're on any other medication, especially other antidepressants or antipsychotic drugs, you will want to share that information with your doctor so that the two of you can make an informed decision about whether or not Zyban (bupropion) is a good option for you.
The FDA also recently issued a warning that, for children and teenagers, any antidepressant may increase the risk of thinking about suicide. Even though Zyban is formulated as a smoking cessation medication, its active ingredient, bupropion, acts as an antidepressant, so it will be important to discuss this with your doctor if you are a teenager, or are considering asking your doctor to prescribe it to a teenager in your care.
Pros and Cons
What are the pros and cons of using bupropion to help quit smoking?
The success rate for Zyban is at least as good as other 'effective' quit smoking aids such as nicotine replacement products.
Unlike nicotine replacement products, Zyban and Chantix allow you begin the treatment a week or two prior to your quit attempt. This allows you to integrate a quit smoking program with the treatment while you are still smoking, and may help you with a natural tapering or 'nicotine fading' technique that can help minimize withdrawal symptoms.
It's easy to use -- it is simply a pill that you take a couple of times a day. (However, don't be fooled into thinking that the pill will do the job all by itself.)
Zyban (bupropion) requires a doctor's prescription, so it may be less convenient than some of the other options. Cost to you depends upon whether you have insurance that will cover the doctor visit and all or part of the cost of the prescription.
As with most medications, Zyban (bupropion) has some side effects and risks associated with it, and is not recommended for people with certain conditions, especially anything that increases your risk of seizures. (See side effects, above.)
Bupropion is one of the two prescription quit smoking medications that have been shown to be effective, so as long as you aren't one of the people who should NOT take it (primarily because of increased risk of seizures), it may be worth exploring this option with your doctor. You may want to also read about Varenicline (Chantix) for comparison purposes.
Of course, it will be important to decide on a behavioral program for eliminating the psychological dependence on smoking, too. Remember that a 'doubling' of the usual 5% cold turkey success rate only yields a 10% success rate. Stack the deck in your favor as much as possible by using a good behavioral program, too. As much as we'd all like it to be, bupropion is not a 'magic pill' for quitting smoking.