Hope UK was speaking after the Royal College said it supported the use of e-cigarettes as a stop-smoking aid, saying tobacco smokers should be actively encouraged to use them as part of efforts to give up.
The Royal College said e-cigarettes could improve and save millions of lives and that there is little evidence to suggest they are a "gateway" to tobacco or other drugs.
There is debate as to what extent e-cigarettes should be available on the NHS, if at all.
Hope UK has said unless better stop-smoking advice and resources become available to partner e-cigarettes, there is a danger people permanently switch to them from tobacco and never stop smoking.
The charity also said that while e-cigarettes are significantly less harmful than tobacco and do help people quit smoking, they can also be a introduction to tobacco and other drugs like marijuana or heroin.
Paul Coppeard, from Hope UK, told Premier: "At the moment they're [e-cigarettes] not being used in any form of control in trying to help people come off using nicotine.
"I could see that there would be ways of doing that if people really wanted to, were motivated to do so.
"But as with everything all the replacement therapies, are they actually working? There are big questions, really."
Listen to Premier's Aaron James speaking to Paul Coppeard:
