A new anti-impotence drug that works like Viagra but is effective for 24 hours is expected to reach Hong Kong within two years.
The pill allows men to respond to sexual stimulation for up to a day after taking it.
At present, Viagra users have to plan when they are going to have sex and then take their tablet at least an hour beforehand. The drug then works for between four and six hours.
The new drug, called Cialis and developed by the makers of Prozac, is in the final stages of testing. A spokesman at manufacturer Eli Lilly's Shanghai office said it was expected to be available in Hong Kong within about two years.
Cialis trials have so far involved more than 4,000 men.
A meeting of the American Urological Association in California last weekend heard that 212 previously impotent men were able to have sex, on average, within 16 minutes of taking Cialis. They could still perform the next day, because the effects of the drug had not worn off.
Side effects were reported by a minority of the men and were similar to those experienced by Viagra patients - headaches, aching muscles and facial flushing.