Vaping to Quit Smoking: What Are the Actual Success Rates?

If you’ve spent any time researching how to quit smoking, you’ve probably run into wildly different claims about vaping. One camp says e-cigarettes are a miracle cessation tool. The other says they’re just trading one addiction for another. The truth, as usual, is somewhere in the middle. And it’s backed by some pretty solid numbers at this point.

I’m going to walk you through the clinical data, the real-world observational studies, and all the caveats you need to understand before making a decision. No hype. No scare tactics. Just the numbers.

The Big Study: Hajek 2019 in the New England Journal of Medicine

This is the study that changed the conversation. Published in January 2019 by Peter Hajek and colleagues at Queen Mary University of London, it appeared in the New England Journal of Medicine. That’s not some obscure journal. It’s one of the most prestigious medical publications in the world. So when a vaping study lands there, people pay attention.

Here’s what they did. They took 886 smokers who wanted to quit and randomly assigned them to two groups. One group got e-cigarettes (a refillable tank system with nicotine e-liquid). The other group got conventional nicotine replacement therapy, meaning their choice of patches, gum, lozenges, inhalers, or sprays. Both groups also received weekly behavioral support for at least four weeks.

The results at one year: 18% of the vaping group had quit smoking, compared to 9.9% of the NRT group. That’s roughly double the success rate.

Let that sink in for a second. In a properly randomized clinical trial, vaping nearly doubled the quit rate compared to traditional NRT products. That’s a meaningful difference.

But before you run out and buy an e-cigarette, there are some important details worth noting.

What the Hajek Trial Got Right

First, the study was randomized and controlled. This is the gold standard in medical research. Participants didn’t get to choose which group they were in, which removes a huge source of bias. If you let people self-select, the more motivated quitters might gravitate toward one method over another, and you’d never know if the method worked or if those people were just more determined.

Second, both groups got behavioral support. This is important because it means the comparison was fair. It wasn’t vaping plus counseling versus NRT alone. Both groups got the same level of support.

Third, they verified abstinence biochemically. They didn’t just take people’s word for it. They tested carbon monoxide levels in exhaled breath to confirm people had actually stopped smoking. This matters because self-reported quit rates are notoriously unreliable.

What the Hajek Trial Didn’t Resolve

Here’s where the honest caveats come in.

80% of the vapers were still vaping at one year. Among the people in the e-cigarette group who successfully quit smoking, the vast majority were still using their e-cigarettes at the 12-month mark. In the NRT group, only 9% were still using NRT at one year.

This is the central tension in the vaping-as-cessation-tool debate. Yes, more people quit smoking with vaping. But most of them became vapers instead of smokers. Whether you consider that a success depends entirely on your perspective.

From a pure harm reduction standpoint, switching from smoking to vaping is a massive win. Public Health England’s widely cited estimate is that vaping is roughly 95% less harmful than smoking. Even if that number is debated (and it is), virtually no serious researcher argues that vaping is anywhere close to as dangerous as combustible cigarettes.

From an “I want to be completely nicotine-free” standpoint, the picture is less rosy. You’ve quit smoking, which is great, but you’re still dependent on nicotine delivery through a device.

Other Clinical Trials Worth Knowing About

The Hajek study isn’t the only one. Several other randomized controlled trials have looked at vaping for cessation.

A 2020 study published in the Cochrane Database of Systematic Reviews pooled data from multiple trials and found moderate-certainty evidence that nicotine e-cigarettes help more people quit smoking than NRT. The pooled quit rate advantage was consistent with what Hajek found.

A 2021 trial from the UK, sometimes called the TEC study, looked at e-cigarettes provided alongside brief behavioral support in a stop-smoking service setting. They found similar advantages for e-cigarettes over standard care.

More recently, studies have continued to reinforce the general finding: in controlled settings with support, vaping outperforms traditional NRT. The effect sizes vary from study to study, but the direction is consistent.

Real-World Observational Data: A Messier Picture

Clinical trials are controlled environments. The real world is not. And when researchers look at how vaping performs as a cessation tool in the general population, the picture gets more complicated.

Several large observational studies have found that vapers are not more likely to quit smoking than non-vapers. Some studies have even suggested that vaping might be associated with lower quit rates. How is that possible when the clinical trials show the opposite?

A few reasons.

Selection bias. In the real world, people who pick up vaping are not a random sample. They might be heavier smokers, less motivated to quit, or more likely to be dual users (smoking and vaping at the same time). When you compare them to non-vapers, you’re comparing apples to oranges.

Dual use. This is the big one. In the Hajek trial, people were given e-cigarettes as a replacement for smoking, with support to help them make the switch. In the real world, a huge percentage of vapers continue to smoke alongside their e-cigarette use. Studies consistently show that anywhere from 30% to 70% of adult vapers are also current smokers, depending on the country and the study.

Dual use doesn’t help you quit. If anything, it might delay quitting by giving you just enough nicotine to take the edge off without fully committing to dropping cigarettes. The people in the clinical trials were told to switch completely. That’s a fundamentally different approach than using a vape when it’s convenient and smoking when it’s not.

No behavioral support. The clinical trials included counseling and follow-up. Most real-world vapers get neither. They buy a device, use it however they see fit, and hope for the best. Behavioral support matters. A lot.

The Dual Use Problem

I want to spend a little more time on dual use because it’s the single biggest reason people fail to quit smoking with vaping.

The logic goes like this: you start vaping, but you don’t fully commit to giving up cigarettes. Maybe you vape at work where you can’t smoke, but you still smoke at home. Or you vape during the week but smoke on weekends. Or you mostly vape but still have a cigarette with your morning coffee.

This pattern does almost nothing for your health. Research shows that even cutting down to a few cigarettes per day doesn’t meaningfully reduce your cardiovascular risk compared to smoking a pack a day. The dose-response curve for smoking and heart disease is steep at the low end. Even a small amount of smoking does a lot of damage.

If you’re going to use vaping to quit smoking, you need to commit to a full switch. Not a gradual one over months and months, but a complete replacement. The Hajek trial participants were told to set a quit date, switch to vaping on that date, and stop smoking entirely. That’s the approach that works.

What About Long-Term Vaping Risks?

This is the elephant in the room. E-cigarettes have only been widely used since the early 2010s. We simply don’t have 30 or 40 years of data on the long-term health effects of vaping. Anyone who tells you vaping is completely safe is being dishonest. Anyone who tells you vaping is just as dangerous as smoking is also being dishonest.

What we know so far:

Vaping does not involve combustion, which eliminates the tar and most of the carcinogens found in cigarette smoke.
E-cigarette aerosol is not harmless. It contains some toxic substances, but at levels dramatically lower than cigarette smoke.
Short-term studies show improvements in respiratory and cardiovascular function when smokers switch to vaping completely.
The EVALI outbreak of 2019 was linked to vitamin E acetate in black market THC cartridges, not commercial nicotine e-cigarettes. But it rattled public trust in vaping generally.

The Royal College of Physicians, one of the oldest medical institutions in the world, concluded in 2016 that the long-term health risks of vaping are unlikely to exceed 5% of the risks of smoking. That’s a strong statement. But “unlikely” is doing real work in that sentence. We won’t know for certain until we have decades of follow-up data.

How These Numbers Compare to Other Methods

For context, here’s how vaping’s success rate compares to other cessation methods in clinical trials:

Cold turkey: About 3-5% success rate at one year.
Nicotine patches alone: About 8-10% success rate at one year.
NRT with behavioral support: About 10-15% success rate at one year.
Varenicline (Chantix): About 25-33% success rate at one year in clinical trials.
Vaping with behavioral support (Hajek): About 18% success rate at one year.

So vaping lands somewhere between NRT and varenicline. It’s better than patches and gum, but probably not as effective as Chantix for pure smoking cessation. However, Chantix comes with its own side effects (nausea, vivid dreams, mood changes) and had availability issues due to recalls in recent years.

Who Should Consider Vaping to Quit?

Based on the evidence, vaping makes the most sense for:

People who have tried and failed with NRT. If patches and gum didn’t work for you, vaping is a reasonable next step. The hand-to-mouth action and the throat hit provide sensory satisfaction that NRT can’t match.
People who are not interested in or can’t take prescription medications. Varenicline and bupropion work well, but they’re not for everyone.
People who are committed to a full switch. If you’re going to vape and smoke at the same time, you’re probably wasting your money and not helping your health.
Heavier smokers who need more nicotine delivery. Vaping can deliver nicotine more efficiently than patches or gum, which may help heavier smokers manage cravings better.

Who Should Think Twice?

People who have never smoked. This should be obvious, but vaping is a harm reduction tool for current smokers. It is not a risk-free hobby.
People whose goal is to be completely nicotine-free. Vaping makes that harder, not easier, because most successful quitters end up as long-term vapers.
Pregnant women. The evidence on vaping during pregnancy is very limited. NRT under medical supervision is a safer bet.

The Bottom Line

The clinical data is real and meaningful. Vaping roughly doubles the quit rate compared to traditional NRT when used with behavioral support and a commitment to fully switching. The 18% vs 9.9% result from the Hajek trial has been supported by subsequent research and meta-analyses.

But the real-world picture is messier. Without a clear plan, support, and commitment to a full switch, vaping doesn’t automatically lead to quitting. Dual use is the most common outcome for people who pick up a vape without a strategy, and dual use is essentially failure from a health standpoint.

If you’re going to try vaping to quit, treat it like any other cessation method. Set a quit date. Switch completely. Get support if you can. And have a plan for eventually stepping down and quitting vaping too, if being nicotine-free is your ultimate goal.

The numbers say it can work. But only if you use it right.