Irish women are 'guinea-pigs' for a new breast enhancing injection which costs €3,500, but only lasts for a year, a leading specialist has said.

It's called the 'boob-job-in-a-jab', but hundreds of women taking the new treatment in Ireland are unaware that Macrolane, a simple injection which instantly increases your cup size, has not been tested by any independent body.

Christopher Caddy, British plastic surgeon and member of the British Association of Plastic, Reconstructive and Aesthetic Surgeons, warned that there was very little in the way of evidence that it is a safe product.

"The only study that was done was supported by Q-Med. Anyone who has Macrolane now will be recruited into Europe-wide research, and will be the guinea-pigs. I am not going to use an untried product on my patients."

It's a beauty treatment in a money-making industry. In 12 months you are left with nothing."

Dr Patrick Treacy, director of the Ailesbury clinic, one of only three clinics in Ireland offering the treatment, said he did not think there was any reason to worry about it.

"Macrolane consists of Hyaluronic acid which already exists within your body, and so is not recognized as a foreign substance.

"The body gradually meta-bolises the acid, which eventually is completely eliminated. Patients will need further treatments to retain volume, probably within a year," he said.

"It came to Ireland in February and has already gone through the roof. Only three clinics in the country are trained to offer it."

Treacy said he believes the popularity of the new treatment is down to the fact that it is scar-free, and can be done in about 15 minutes. "For the first time we can do things that are quick and safe."

New to the European market this year and manufactured by Q-Med, a bio- technology company which primarily manufactures and sells medical implants, it says the compound is completely safe as it has been used to fill facial contours for years.

The product is also being used for penis enlargement at Castleknock Cosmetic Clinic, at the cost of €1,000.