A simple DNA test could spot which smokers have an addictive gene and would likely benefit from particular quit methods, say scientists.
The test requires a small sample of blood
Smoking cessation treatment could be tailored according to the individual's gene profile, according to the Oxford University Team.
The NicoTest, developed by g-Nostics, can be carried out in the same way that diabetics self-test for blood-sugar.
But at a cost of nearly £100, some say traditional quit methods may suffice.
Others said the claims made for the test were not supported by the scientific evidence.
But g-Nostics said the veracity of the science was perfectly sound.
The Oxford team says those found to have the addictive gene, present in about 35% of all people, have a greater chance of quitting their habit if they use nicotine replacement therapy (NRT).
Those without the gene are likely to succeed if they use other methods nicotine-free methods, according to Dr Rob Walton and colleagues.
They found four in 10 smokers with the "addiction gene" could successfully give up if they used the right NRT - double the number of those without the gene who could quit with NRT.
The test can also give a "metabolic profile" which shows how quickly a smoker is able to clear nicotine from their body, helping to determine the right dose of NRT, say the researchers.
In theory, it could also be used to check which children have the addictive gene and are at risk of becoming addicted to nicotine in the future.
Dr Walton said: "I think many people would like to know whether their children have the gene or not.
"But what we are lacking at the moment is a treatment so if you know you have the gene and you are a child you can prevent yourself becoming dependent on tobacco.
"So there are lots of ethical issues that need to be sorted out before we could offer anything like that."
Mark Tucker, co-founder of g-Nostics, said the test should help more smokers quit successfully.
Staying off the fags
"About 27% of the Nation smokes, which amounts to about 13m people.
"Of those, around 70% would like to quit if they felt they had enough support. Unfortunately around 96% who try to quit actually fail."
He said there would probably be other genetic variations found in the future that they could build into the test to make it even more specific.
A spokeswoman from Action on Smoking and Health said: "I'm a bit sceptical.
"Some people are social smokers and find it difficult not to smoke when out with friends, whereas others are addicted to nicotine.
"I'm not sure people need a gene test to know which type they are.
"Most people know themselves what it is about smoking that they like and what they find difficult.
"However, it might be useful for some people, but it depends how much it costs."
She advised any smoker wanting to quit to visit their local stop smoking service.
"People who go cold turkey and give up on their own, about 5% succeed.
"Whereas if you go to a stop smoking service it can increase the success rate about four-fold so 20% succeed in giving up."
GeneWatch UK said: "The NicoTest could mislead smokers and potentially harm health because people are likely to be given wrong advice about how to best increase their chance of quitting smoking.
"The role of genes in nicotine addiction and treatment is still poorly understood."