This deadly poison is promoted as if it's a routine, safe, procedure but little is known of the long-term effects.
I've always wondered why women would inject poison into their faces in an attempt to look younger.
It's surprised me, too, that health officials would approve a procedure that involves injecting poison into people's faces three or four times a year.
But since it was approved for cosmetic use in 2002, the Botox injection has become the world's most popular cosmetic procedure. Thousands of New Zealand women have Botox injections every three or four months, and it's becoming popular with men too.
A Botox injection paralyses the facial muscles into which it is injected by blocking a group of nerves, so the muscles can no longer move or 'frown'. The effects last for about three months, which is why most Botox users have a top-up injection about four times a year.
In our looks obsessed culture, being injected with Botox is promoted as if it's a routine, safe, non-surgical procedure that anyone who wants to avoid looking old, or developing facial lines, should use.
But you can't help wondering how safe Botox really is, when it's made from a toxin that's produced by the bacteria Clostridium botulinum, a deadly neurotoxin that can cause botulism, a rare and life threatening paralytic illness.
When used cosmetically, it's injected in tiny amounts. But in large doses it's one of the most powerful poisons known to man.
The Consumer Medicine Information on the Ministry of Health website warns that it can spread from the site of the injection and cause difficulties in breathing and swallowing which, it notes, "can be life-threatening".
Other side-effects listed on the website include: numbness, droopy eyelids; double or blurred vision, trouble speaking. If this is not off-putting enough, it mentions that Botox "contains albumin, an extract of human blood, and it carries an extremely remote risk for transmission of viral diseases."
The Medicines Data sheet mentions that there have been rare reports of death from Botox, and that excessive doses may produce muscular paralysis, including of the respiratory muscles.
It points out that its safe use depends on it being properly stored, given in the right doses and properly administered by a qualified doctor.
But do it yourself Botox kits are on sale on the internet, and there are reports of people who are left with disfigured faces from inexperienced applicators injecting Botox, or giving it to the wrong muscles or in the wrong amounts.
Botox manufacturers claim that side-effects are uncommon and fleeting. But that's not what is said on a website devoted to supporting Botox users suffering from side-effects. It makes for sobering reading, with women reporting muscle weakness, nerve damage, headaches, pain, stiffness and other adverse effects.
Another concern is that repeated Botox injections over several years can weaken and shrink affected muscles, or even adjacent muscles, giving the face a distorted look.
Overuse can result in a frozen, immobile face that looks like a startled Barbie doll, and can eventually destroy a person's ability to make normal facial movements such as lifting an eyelid.
A nerve or muscle that's being routinely injected with Botox may not be able to absorb all of the toxin, and it can end up in the blood stream. It can also cause nerve damage, or migrate from the injection site to other parts of the body.
Some fear it could move within the nervous system and even end up in the brain. An Italian animal study found it can attach itself to nerve cells within rats, opening up the possibility that it could do the same in humans, and travel to the brain.
The scientist who conducted the animal experiment says not enough is understood about how the toxin migrates in the human body, and more research is needed.
Dr Peter Misra, a leading London neurologist, agrees that the long-term effect of botulism on the brain, nervous system and muscles are unknown. He says it's being used ahead of clear scientific evidence, on the basis of small-scale studies, and that its growing use means more patients are at potential risk.
There have been no studies of the long-term health effects of routinely injecting low doses of this rather nasty poison over many years, as safety studies only examined its use over a couple of years. Dr Stewart Jessamine, head of Medsafe, acknowledges that "we don't actually know if there are long-term side-effects. This is a relatively new medicine, and it is a potent poison. It's not been used for prolonged periods."
If this is the case, it begs the question, what might the long-term consequences be for women who get repeat injections every three months for years on end, and intend to do so for the rest of their lives? And how is the widespread use of this toxin being monitored in New Zealand?
The answer, surprisingly, is that nobody is really monitoring it at all. Most cosmetic surgery takes place privately, with little oversight or regulation. It's a prescribed medicine, and patients can report adverse effects to the Medicines Advisory Committee, or complain to a disciplinary body. But aside from that there's no official monitoring of how it's administered, or what its potential long-term effects may be.
In Britain there are calls for tighter regulation of cosmetic procedures such as dermal fillers and Botox injections, with many arguing that they should only be carried out in licensed premises, by accredited and properly trained doctors.
Surely the rules should be tightened here too, so we can avoid a repeat of previous health disasters, such as the silicon breast implant fiasco, in which 50,000 women were given faulty implants.
In the meantime, it's a case of 'buyer beware'. Perhaps the last word should go to actress Drew Barrymore who said recently: "To all those women putting botulism in their faces -we don't know what the long term effects are, so stop! I'd rather look like a basset hound than do that to my face."
Sue Kedgley is a former Green MP.