Stem cells have been hailed as a potential aid for conditions ranging from Alzheimer's disease to diabetes.
Stem cell treatments are likely to be years away
But leading fertility expert Lord Robert Winston has warned the immediate benefits of the therapy have been "over-hyped".
His comments raise the issue of how science is presented to the public - which may then expect speedy results when actual advances are likely to be many years away.
Stem cells have been the focus of a great deal of scientific, media and public attention in recent years.
They are the body's "master cells" and have the ability to produce all kinds of tissues.
Scientists working in many fields are looking to use stem cells to replace the failed cells responsible for many conditions.
Lord Winston told the British Association's Festival of Science in Dublin on Monday that there might be a backlash against science if stem cell research failed to deliver quickly - and that a major part of the problem was how scientific findings were presented to the public.
'No absolute promises'
Speaking on BBC Radio 4's Today programme, he said: "Scientists need to be very careful about how they engage with the public. It's dangerous in the long term to exaggerate.
"To raise public expectation too high carries grave risks."
Lord Winston, president of the British Association, added: "If you make claims that can't be justified, or the public perceive that they can't be justified, of course that mistrust grows and that can't be good for science.
"We can't make absolute promises about how things are going to turn out."
A spokeswoman for the Parkinson's Disease Society said there was some encouraging progress being reported in stem cell research.
But she said there was concern about how the 120,000 people with the condition, and their relatives, perceived new findings.
"We know there is a real danger that researchers can give out over-optimistic messages and mislead vulnerable people who may be anxious for a new treatment.
"There are still many difficult scientific questions to be answered regarding the potential use of stem cells in therapies and there is a long way to go before any clinical trials can be considered."
And Professor Clive Ballard, director of research at the Alzheimer's Society, said: "Whilst we do not feel that the potential benefits stem cell research could bring have been 'hyped', we believe it will be some time before this area of research delivers a realistic treatment for Alzheimer's disease in clinical practice."
But Dr Stephen Minger, director of King's College London Stem Cell Biology Laboratory, said he did not think the potential of stem cell therapies was over-exaggerated.
"I can't think of any instances where stem cell scientists are over-hyping their findings. We try very hard to promote the idea that it's going to take a long time.
Stem cells may aid some brain conditions
"And we're not talking about cures, or saying that stem cells will be able to help every disease under the sun."
Dr Minger said the UK media also behaved responsibly in not over-exaggerating the potential benefits of the therapy.
But he added: "I get tens of calls and letters a week from people asking for stem cell therapy for various conditions.
"Maybe scientists have not been forceful enough in saying how long it's going to take for stem cells to work and which conditions they will work for.
"And perhaps we need to be more straightforward about our message."
Other scientists said stem cells offered other benefits which were more immediate, such as the ability to use them to assess medicines.
Dr Anne Bishop, of Imperial College London, said: "We can test drugs to see whether they work properly on these cells, and can see whether they react to toxins.
"And we may be able to do away with lots of animal experiments because we can test on these cells."