Nicole Kidman has finally admitted that she has tried Botox. Well, no surprises there. But what is news – at least in my book  - is that says she's over it now.

"I've tried a lot of things, but aside from sports and good nutrition, most things don't make a difference," Kidman, who is 43, told the German magazine TV Movie. "I have also tried Botox.” Then she added: "I didn't like how my face looked afterwards. Now I don't use it anymore - I can move my forehead again. “

Anyone who has followed Ms Kidman over the last few years will likely agree that she was starting to look a bit strange. But there are compelling health reasons other than appearance and forehead mobility to quit Botox.

A couple of years ago, the results of a study were released showing that injected botulinum toxin can travel to the brain, degrading proteins. The study, published in the Journal of Neuroscience last week, was conducted in Italy. Rats were given injections of botulinum around their whisker muscles and three days later it was found that some of the toxin had reached their brains. It was still there six months later. To be fair, not all of it; most of it remained in situ. The Botox that did reach the brain acted on the nerves and entered the brain cells.

Allergan, the makers of Botox, say that the Italian study is inconclusive. Maybe, but a another study in Canada, this time on cats, revealed that the toxin passed easily into the surrounding muscles and weakened all the muscles in the area. The results support other research that has already shown that botulinum can pass through tissue surrounding muscle.

All of which makes an amusing post on Spoof.com that Nicole and hubby Keith Urban had a second child by a surrogate to avoid “pre-natal Botox poisoning” not all that far off the mark.

More recently, researchers at Barnard College New York claimed that Botox participants (versus a control group that were injected with Restylane "exhibited an overall significant decrease in the strength of emotional experience”. This, they say, is because feedback from facial expressions to the brain can influence the experience of emotions.

And emotions for an actress would be fairly useful , wouldn’t you say.