Painful injections could become a thing of the past thanks to new technology.
Some patients fear injections
Harvard University researchers found that instead of inserting a needle into the skin, it is possible to fire a stream of gas at the skin's surface.
The gas contains sharp particles which remove the surface layer of the skin and create tiny holes allowing a drug to be administered.
The development could benefit people such as diabetics who need regular injections, campaigners said.
The technique, known as microscission, bombards small areas of the skin with a stream of gas holding tiny crystals of inert aluminium oxide.
The rough surface-layer of the skin is removed, creating tiny holes - microconduits - in the underlying layers of the skin.
The crystals and loosened skin are taken away with the gas flow and the whole process takes less than 20 seconds.
The researchers at Harvard-MIT Division of Health Sciences and Technology tried the technique by giving a local anaesthetic to volunteers.
After creating four of the microconduits, a pad soaked with an anaesthetic was applied.
Volunteers said there was a loss of feeling, showing the anaesthetic had been successfully delivered.
They said the microscission itself was much less painful than a needle and simply felt like a gentle stream of air against the skin.
Dr James Weaver and his team at Harvard found that the onset of the anaesthesia was quicker in shallower microconduits than in deeper ones.
This could be because the deeper ones produce some blood and this may impede the introduction of the anaesthetic.
However, deeper microconduits could be useful for patients with diabetes who have to regularly check the glucose level in their blood.
Debbie Hammond, diabetes care advisor at Diabetes UK, said: "A needle-free way to administer insulin or obtain blood for blood glucose testing would be a very useful alternative for people with diabetes, especially for those who are uncomfortable with needles and traditional methods of injecting."
However, she warned that widespread use of the technique might still be some way off.