Botox treatment to rid yourself of unsightly wrinkles may be addictive, research has found.
Botox is gaining in popularity
Doctors found 40% of patients using Botox expressed a compulsive desire for further treatments.
People need to keep having jabs otherwise the effects of the treatment - which paralyses the muscles - rapidly wears off.
The research will be presented at a meeting of the British Association of Aesthetic Plastic Surgeons.
There was a 50% increase in the number of people treated with Botox injections in the UK during 2005.
Mintel, the market research group, estimates more than 100,000 treatments are now given in Britain each year.
Fear of ageing
The study was carried out by Dr Carter Singh, who has a degree in psychology and is based at Derbyshire Royal Infirmary, and the consultant plastic surgeon Martin Kelly, of London Plastic Surgery Associates.
They surveyed clients at 81 clinics, and compared Botox users to people who used other, less invasive beauty treatments.
- Over 50% of those who use Botox expressed a lack of control over the natural ageing process
- Nearly 50% expressed anger at people criticising them for Botox use
- Over 40% expressed a compulsive motive for using Botox repetitively
- Over 50% of people using Botox reported actually "feeling" younger, rather than just looking younger.
Dr Singh said regular Botox users seemed to have a greater concern about the ageing process, and their inability to control it.
He said: "Botox has a good safety profile, but it also has potentially addictive qualities.
"Botox changes the physical appearance of a person's skin or face, and that ultimately leads to improved body image.
"This enhances psychological well-being. It is easy to see how people could become addicted."
Colin Angus, a celebrity agent who has regularly used Botox, said: "When I first had it done the changes were tremendous, but I think probably now I have just got used to the way I look.
"In my job, image is very important. No matter what anybody says, you have to look good."
Botox is a highly purified and much diluted form of the botulism bacterium, responsible for deadly food poisoning.
It blocks the transmission of acetylcholine from the nerves to the muscle.
Acetylcholine is a neurotransmitter which send a message to the muscle telling it to contract or tense up.
With the flow of acetylcholine blocked or significantly reduced, the muscle can no longer retract and it relaxes. As a result, the wrinkled areas smooth out and soften.
However, the effect wears off after four to six months.
Women who are pregnant or breastfeeding should not use Botox.