Botox is a bizarre procedure - paralysing muscles to smooth out expression lines on the face - but it has been embraced by the wealthy and image-conscious around the world. In the US, people have Botox parties, where medics with sharp marketing skills line up clients, lay on the drinks and nibbles, and call in each one for a quick consult and a few jabs in the offending wrinkles. A regular reader thinks her mother in her 50s might be a candidate for cosmetic surgery. She says she has heard a lot about the wonders of Botox, but wants to know if it's safe. She's right to ask. No matter how long a drug has been known to humans, it may never be totally safe. Even aspirin kills if given to the wrong person in the wrong dosage at the wrong time. Botox, although heavily marketed by its makers as a wonder drug, is a poison. It comes from a toxin produced by a bacteria - clostridium botulinum - which causes a lethal form of food poisoning. It acts by poisoning the communication channel between a nerve and the muscle it controls. This prevents signals ordering the muscle to contract from getting through, so the muscle no longer functions. Large doses of botulinum toxin can paralyse your breathing muscles, so if you don't get to hospital quickly you'll die from lack of oxygen. However, the dose of botulinum toxin in Botox is very small. Although there have been cases of leakage that has paralysed muscles around the ones being treated, it hasn't caused lethal side effects. However, four out of 10 people who receive Botox have side effects, mostly the likes of nausea and headaches. Some suffer drooping eyelids on one side of the face for several weeks. Wrinkles are marks on the skin caused by regular muscle movement. We have them everywhere, but we develop them around the muscles we use most. The face takes longer to show permanent signs of muscle movements than other actively moved parts of the body because we're born with a protective layer of fat under the skin. But as we age, the fat layer lessens and the skin becomes less elastic, especially with sun damage, resulting in permanent muscle lines. Chinese people have a genetic advantage in the age stakes because, regardless of body weight, they tend to store their fat just under the skin, keeping their faces smooth for longer. After Botox, the muscles under the wrinkles no longer contract, so the wrinkles don't show. Your face also has less expression, but if you're the type who fears wrinkles you may not mind if your frown isn't so obvious. So, should our reader tell her mother to have Botox? I'm not a fan of unnecessary surgery, because each brings a new set of problems. If the problem they fix is a serious one, the trade-off is acceptable. But cosmetic surgery is never the answer in my view. However, for those who decide that Botox is for them, make sure you to go to an experienced plastic surgeon who specialises in facial problems. The operators in some beauty salons use a 'paint by numbers' approach, injecting the Botox in the same place on each patient, lacking the specialist knowledge to tailor the treatment to each person's needs.