Men have been given unrealistic expectations of the benefits of Viagra, researchers have said.
Viagra has been widely covered
Erectile dysfunction sufferers who took the drug but found it did not work were left demoralised.
A study of 40 men by the Royal Hampshire Hospital, published in the British Medical Journal, showed most had high hopes for the treatment.
The media's "sensational reporting" of Viagra was blamed for the distress caused when it failed to work.
Researchers interviewed a random sample of 40 men with an average age of 52 who had been prescribed Viagra and had attended a men's health clinic in the year before the study.
Erectile dysfunction caused serious distress to all those men who suffered from it, with marked effects on their self-esteem and well-being.
There was generally an improvement in well-being when Viagra, the generic name for which is sildenafil, was successful. But when it failed the distress was severe.
Many of the men said this was the fault of media hype.
The researchers at the Royal Hampshire Hospital's men's health clinic said: "The media have had a major effect on expectations of sildenafil, and in retrospect, less sensational reporting would have lowered those expectations to the patients' benefit."
Health professionals also needed to be aware of the extreme distress erectile dysfunction could cause, they said.
Ann Tailor, director of the Sexual Dysfunction Association, said: "There was a very high expectation of Viagra. It was portrayed as a wonder drug in the press - take this and get the best sex life.
"For many people who have taken it, it has been safe and effective, but there have been a number of men who it has not worked for."
The reasons why it had not worked were not always understood, she said. The drug should not be taken after food or alcohol and sexual stimulation is still required for it to have the desired effect.
Mrs Tailor added that if patients had psychological problems because of the failure of the treatment, or the erectile dysfunction itself, they should seek sexual therapy.
Prof Dinesh Bhugra, at the Institute of Psychiatry in London, said: "There is no doubt that people who invest a lot of hope in a particular kind of treatment, when it does not work, they feel much worse because it makes them stand out.
"They think, if it works for everyone else I must be much worse."
However, the reality was that there were a number of factors in individual cases, both physical and psychological, Prof Bhugra said.
Health professionals should consider a range of treatments suitable to the patient, he said.